JP2020056273A - Paving binder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pavement binder and a pavement mixture capable of asphalt pavement having excellent workability and crack resistance after construction. [1] A pavement binder composed of a polyamide resin alone or a mixture of a polyamide resin and asphalt, which is used by blending it in a pavement mixture, and the blending amount of the polyamide resin blended in the mixture is polyamide. A pavement binder having a total amount of resin and asphalt of 90% by mass or more, a softening point of the polyamide resin of 60 to 105 ° C., and a melt viscosity of the polyamide resin at 180 ° C. of 140 to 500 mPa · s. , And [2] a pavement mixture containing the above-mentioned pavement binder and aggregate. [Selection diagram] Fig. 1

Description

  The present invention relates to a paving binder and a paving mixture.

Asphalt pavement using an asphalt mixture is widely used because pavements such as motorways, parking lots, cargo yards, and sidewalks are relatively easy to lay and the time required from the start of pavement work to the start of traffic is short. ing.
In asphalt pavement, a pavement is formed by using an asphalt mixture obtained by combining aggregate with petroleum asphalt (straight asphalt) or polymer modified asphalt obtained by mixing petroleum asphalt with a polymer material such as SBS. ing. With this asphalt pavement, the pavement road and the like have good hardness and durability with relatively simple construction.
However, there is a problem that asphalt pavement deteriorates over time and cracks occur due to fatigue, temperature stress, shrinkage and the like.

  On the other hand, there is a concrete pavement as a pavement method. Concrete pavement is superior in rigidity to asphalt pavement, but has a drawback that cracks easily occur due to temperature changes due to poor flexibility. For this reason, concrete pavement requires joint work to prevent cracks, and the work of flattening the pavement surface is complicated and requires a long curing period. Inferior in terms of

Under such circumstances, an asphalt mixture containing a polyamide resin, a binder for paving, and the like have been proposed.
For example, Patent Document 1 discloses an asphalt mixture containing an aggregate, a polyamide resin, and asphalt, wherein the polyamide resin has a softening point of 60 to 150 ° C., and preferably has a melt viscosity at 180 ° C. of 1000 mPa. Asphalt mixtures that are less than or equal to s are disclosed.
Patent Document 2 discloses a pavement binder used for a pavement mixture, comprising a polyamide resin alone or a binder mixture of a polyamide resin and asphalt. In the case of the binder mixture, the compounding ratio of the polyamide resin is A pavement binder having a polyamide resin and asphalt of 90% by mass or more, a softening point of the polyamide resin of 70 to 100 ° C, and a melt viscosity at 180 ° C of 180 mPa · s or less. It has been disclosed.

JP 2010-236345 A JP 2014-31649 A

In asphalt pavement, further improvement has been desired from the viewpoint of improvement in resistance to severe temperature conditions and traffic loads and convenience in construction.
An object of the present invention is to provide a pavement binder and a pavement mixture that enable asphalt pavement having excellent workability and crack resistance after construction.

The present inventors have found that the above problem can be solved by using a polyamide resin containing a specific amount of a specific polyamine component and having a specific softening point and a specific melt viscosity as a binder.
That is, the present invention provides the following [1] and [2].
[1] A pavement binder which is composed of a polyamide resin alone or a mixture of a polyamide resin and asphalt and is used by being blended into a pavement mixture,
The blending amount of the polyamide resin to be blended in the mixture is 90% by mass or more based on the total amount of the polyamide resin and asphalt;
The polyamide resin has a softening point of not less than 60 ° C. and not more than 105 ° C., and the melt viscosity at 180 ° C. of the polyamide resin is not less than 140 mPa · s and not more than 500 mPa · s,
The polyamide resin is a polycondensate of a carboxylic acid component and an amine component containing a polyamine, and the amine component is at least two of the same or different kinds selected from aliphatic diamines, aliphatic triamines, and aromatic diamines. A pavement binder comprising the above polyamine, wherein at least one is an aliphatic diamine, and the amount of the largest amount of the polyamine is from 51 mol% to 75 mol% with respect to the total amount of the amine.
[2] A pavement mixture containing the above-mentioned pavement binder and aggregate.

  ADVANTAGE OF THE INVENTION According to this invention, the binder for paving and the mixture for paving which enable asphalt pavement excellent in workability and crack resistance after construction can be provided.

5 is a photograph showing the state of the paving mixture obtained in Example 2. 9 is a photograph showing the state of the paving mixture obtained in Comparative Example 6.

[Pavement binder]
The pavement binder of the present invention is a pavement binder which is used by being compounded with a pavement mixture, comprising a polyamide resin alone or a mixture of a polyamide resin and asphalt.
The blending amount of the polyamide resin to be blended in the mixture is 90% by mass or more based on the total amount of the polyamide resin and asphalt;
The polyamide resin has a softening point of not less than 60 ° C. and not more than 105 ° C., and the melt viscosity at 180 ° C. of the polyamide resin is not less than 140 mPa · s and not more than 500 mPa · s,
The polyamide resin is a polycondensate of a carboxylic acid component and an amine component containing a polyamine, and the amine component is at least two of the same or different kinds selected from aliphatic diamines, aliphatic triamines, and aromatic diamines. The above polyamines are contained, at least one of them is an aliphatic diamine, and the maximum amount of the polyamine species is from 51 mol% to 75 mol% with respect to the total amount of the amine.

In the present specification, the “paving mixture” refers to a mixture that includes a paving binder and an aggregate and can be used for pavement construction. The pavement mixture may contain, for example, asphalt additives such as an anti-peeling agent and an intermediate warming agent, a filler, and other components in addition to the pavement binder and the aggregate.
The term "paving binder" refers to a binder for bonding aggregates, for example, the polyamide resin according to the present invention, a mixture of the polyamide resin and asphalt, and further, a tar and various resin components. And the like.

<Polyamide resin>
The polyamide resin is a polymer compound having an amide bond (—CONH—), and is a polycondensate of a carboxylic acid component and an amine component. The polyamide resin can be obtained by a condensation polymerization reaction between a carboxylic acid component and an amine component, a ring-opening polymerization reaction of a cyclic lactam, a self-condensation reaction of an amino acid or a derivative thereof, and the like.

The softening point of the polyamide resin used in the present invention is 60 ° C. or higher, preferably 70 ° C. or higher, more preferably 75 ° C. or higher, further more preferably 80 ° C. or higher, from the viewpoint of crack resistance and workability. And it is 105 degrees C or less, Preferably it is 100 degrees C or less, More preferably, it is 95 degrees C or less.
The melt viscosity at 180 ° C. of the polyamide resin used in the present invention is 140 mPas or more, preferably 150 mPas or more, more preferably 150 mPas or more, from the viewpoint of improving the shape retention and crack resistance of the uncured pavement mixture. Is 160 mPa · s or more, more preferably 170 mPa · s or more, even more preferably 180 mPa · s or more. The melt viscosity is 500 mPa · s or less, preferably 400 mPa · s or less, more preferably 350 mPa · s or less, from the viewpoint of obtaining good workability while ensuring uniform mixing with aggregates and the like. It is.
The measurement of the softening point and the melt viscosity of the polyamide resin can be performed by the methods described in Examples.

(Production method of polyamide resin)
As a typical method for producing a polyamide resin, a method for producing a polyamide resin by a polycondensation reaction between a carboxylic acid component and an amine component will be described below.

(Carboxylic acid component)
As the carboxylic acid component, a monovalent carboxylic acid, a divalent carboxylic acid, and a polymerized fatty acid can be used.
The monovalent carboxylic acid has at least 4 carbon atoms, preferably at least 8 carbon atoms, more preferably at least 12 carbon atoms, and has at most 24 carbon atoms, preferably at most 22 carbon atoms. Carboxylic acids.
Specific examples of the saturated aliphatic monocarboxylic acid include butyric acid, valeric acid, lauric acid, palmitic acid, stearic acid, argidic acid, behenic acid and the like.
As unsaturated aliphatic monocarboxylic acids, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, erucic acid, mixed fatty acids obtained from natural fats and oils (tall oil fatty acids, rice bran fatty acids, soybean oil fatty acids, tallow fatty acids, etc.) And the like.
Examples of the divalent carboxylic acid include aliphatic or aromatic divalent carboxylic acids having 4 or more carbon atoms, preferably 6 or more carbon atoms, and specific examples thereof include succinic acid, alkenylsuccinic acid, adipic acid, and sebacic acid. , Dodecane diacid, phthalic acid, isophthalic acid, terephthalic acid and the like.

The polymerized fatty acid is a polymer obtained by polymerizing a monobasic fatty acid having an unsaturated bond, or a polymer obtained by polymerizing an esterified product of a monobasic fatty acid having an unsaturated bond. Examples of the polymerized fatty acid include those obtained by a dehydration condensation reaction of a divalent carboxylic acid derived from vegetable oil or fat.
Examples of the monobasic fatty acid having an unsaturated bond include unsaturated fatty acids having a total of 8 to 24 carbon atoms having usually 1 to 3 unsaturated bonds, and specific examples thereof include oleic acid, linoleic acid, Linolenic acid, natural dry oil fatty acids, natural semi-dry oil fatty acids, and the like.
Examples of the esterified product of a monobasic fatty acid having an unsaturated bond include an esterified product of the above monobasic fatty acid having an unsaturated bond and an aliphatic alcohol, preferably an aliphatic alcohol having 1 to 3 carbon atoms. No.

The polymerized fatty acid which is a polymer obtained by polymerizing a monobasic fatty acid having an unsaturated bond or a polymer obtained by polymerizing an esterified product of a monobasic fatty acid having an unsaturated bond is mainly composed of a dimer. Components are preferred. For example, as a polymer of an unsaturated fatty acid having 18 or more carbon atoms, the composition is 0 to 10% by mass of a monobasic acid (monomer) having 18 carbon atoms, and a dibasic acid (dimer) 60 having 36 carbon atoms. An acid having a carbon number of from 99 to 99% by mass and a tribasic acid or more (trimer or more) of 30% by mass or less is available as a commercial product.
The above carboxylic acid components can be used alone or in combination of two or more, but it is more preferable to use a monovalent carboxylic acid and a polymerized fatty acid in combination.

Among the carboxylic acid components, a monovalent carboxylic acid is preferable, and the content thereof is from 5 molar equivalent% to 50 molar equivalent% based on the total amount of the carboxylic acid component.
The content of the monocarboxylic acid in the carboxylic acid component is preferably at least 8 molar equivalent%, more preferably at least 10 molar equivalent%, from the viewpoint of improving crack resistance and workability.
When a monovalent carboxylic acid and a polymerized fatty acid are used in combination as the carboxylic acid component, the mixing ratio of the monovalent carboxylic acid is preferably 10 mol% or more, more preferably 15 mol equivalent, based on the total amount of the carboxylic acid component. % And preferably less than 50 molar equivalent%, more preferably less than 40 molar equivalent%. Further, based on the total amount of the carboxylic acid component, the polymerized fatty acid is preferably at least 50 molar equivalent%, more preferably at least 60 molar equivalent%, and preferably less than 90 molar equivalent%, more preferably less than 85 molar equivalent%. It is.
By using a monocarboxylic acid, particularly an unsaturated aliphatic monocarboxylic acid and a polymerized fatty acid as the carboxylic acid component, it becomes easy to adjust the melt viscosity of the obtained polyamide resin.

(Amine component)
Examples of the amine component include polyamines, aminocarboxylic acids, and amino alcohols.The polyamide resin used in the present invention is preferably aliphatic diamine, aliphatic triamine and aromatic diamine from the viewpoint of crack resistance and workability. And at least two or more of the same or different polyamines selected from the group consisting of at least one aliphatic diamine.
The polyamide resin used in the present invention contains at least one aliphatic diamine as an amine component, as two or more polyamines, two or more aliphatic diamines, one or more aliphatic triamines, and one or more aliphatic diamines. It preferably contains two or more polyamines selected from aromatic diamines, and more preferably contains two or more polyamines selected from two or more aliphatic diamines and one or more aliphatic triamines.

As the aliphatic diamine, an aliphatic diamine having 2 or more and 6 or less carbon atoms is preferable, and two or more kinds selected from ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, and the like can be mentioned. Methylene diamine is preferred.
Examples of the aliphatic triamine include diethylene triamine, dipropylene triamine, and benzene triamine, and diethylene triamine is preferable.
Examples of the aromatic diamine include xylylenediamine, diphenylmethanediamine, diaminodiphenylsulfone, and methylenebischloroaniline, with xylylenediamine being preferred.

When the polyamide resin is composed of a single amine component, the polyamide resin shows a high softening point, but by including two or more polyamines having different structures, the orientation of the amide group between polyamide molecules can be adjusted. . Thereby, since the amount of crystallization and hydrogen bonding caused by the intermolecular interaction and the like of the polyamide resin can be reduced, it is considered that shrinkage with the passage of time can be reduced and the occurrence of cracks in the pavement can be suppressed. . Furthermore, by including two or more polyamines having different structures, the softening point of the polyamide resin can be lowered, and the desired softening point can be easily adjusted.
The melt viscosity of the polyamide resin increases as the charge ratio of the monocarboxylic acid component decreases. However, since the molecular weight varies depending on the reactivity of each monomer, the melt viscosity does not depend solely on the charging ratio of the monocarboxylic acid. However, when two or more kinds of polyamines having different structures are used in combination, it is thought that the melt viscosity changes because the molecular weight is different due to the difference in reactivity of each monomer as compared with the polyamide obtained using a single amine. Can be

As the two or more aliphatic diamines contained in the polyamide resin, ethylene diamine and hexamethylene diamine are preferable.
More preferably, the polyamide resin further contains diethylene triamine as the aliphatic triamine. When an aliphatic triamine is contained, its content is preferably at least 3 mol%, more preferably at least 5 mol%, still more preferably at least 7 mol%, and preferably at least 20 mol%, based on the total amount of the amine. %, More preferably not more than 15 mol%, further preferably not more than 12 mol%.

Among the polyamine species contained as the amine component, the largest amount of the polyamine species is preferably an aliphatic diamine, and more preferably ethylene diamine.
The amount of the largest amount of the polyamine species is from 51 mol% to 75 mol% with respect to the total amount of the amine from the viewpoint of improving crack resistance and workability. The amount of the highest polyamine species is preferably greater than or equal to 55 mol%, and preferably less than or equal to 70 mol%, more preferably less than or equal to 65 mol%.

In the differential scanning calorimetry (DSC) according to JIS-K7121, the polyamide resin used in the present invention is heated at 20 ° C./min and cooled at 50 ° C./min from the viewpoint of improving crack resistance. Is preferably 4.2 J / g or less.
The heat of crystallization (ΔHc) is preferably 3 J / g or less, more preferably 2.5 J / g or less, even more preferably 2.3 J / g or less, and preferably more than 0 J / g, more preferably 1 J / g or less. 0.5 J / g or more, more preferably 1.7 J / g or more.
The heat of crystallization (ΔHc) is obtained by raising the temperature of the polyamide resin at a temperature lowering rate of 20 ° C./min, and the temperature of an exothermic peak (crystallization peak) appearing when the temperature is lowered at a rate of 50 ° C./min. Where Tc is the peak area, and the measurement can be performed by the method described in Examples.

(Polycondensation reaction conditions)
The polyamide resin is obtained by subjecting a carboxylic acid component and an amine component, preferably a carboxylic acid component containing a monovalent carboxylic acid and a polymerized fatty acid, and an amine component containing a polyamine to a polycondensation reaction under known reaction conditions. Obtainable.
Polyamide resin used in the present invention, in order to improve the resistance to severe temperature conditions and load conditions, it is preferable to make the molar equivalent ratio of the carboxylic acid component and the amine component substantially equal, specifically, The equivalent ratio (carboxy group / amino group) is preferably in the range of 1.0 / 1.2 to 1.2 / 1.0, more preferably in the range of 1.0 / 1.1 to 1.1 / 1.0. .
The polycondensation reaction temperature is preferably 180 ° C. or higher, more preferably 190 ° C. or higher, and is preferably 250 ° C. or lower, more preferably 240 ° C. or lower.
The desired polyamide resin used in the present invention can be easily produced by adjusting the reaction temperature and the reaction time under conditions of the molar equivalent ratio of the carboxylic acid component and the amine component, and in some cases, by adding a monovalent carboxylic acid or a monoamine. be able to.

<Asphalt>
Various asphalts can be used as the asphalt used in the present invention. For example, in addition to straight asphalt, which is petroleum asphalt for pavement, modified asphalt such as blown asphalt and polymer-modified asphalt, and regenerated asphalt.
The straight asphalt and the blown asphalt refer to “straight asphalt” and “blown asphalt” respectively defined in JIS K2207 “petroleum asphalt”.
The polymer-modified asphalt is asphalt modified with a polymer material such as a thermoplastic elastomer and a thermoplastic resin. Examples of the thermoplastic elastomer include styrene / butadiene / styrene block copolymer (SBS), styrene / isoprene / styrene block copolymer (SIS), and ethylene / vinyl acetate copolymer (EVA).
Examples of the thermoplastic resin include ethylene / ethyl acrylate copolymer, polyolefin such as polyethylene and polypropylene, and polar group-modified polyolefin such as maleic anhydride-modified polyethylene and maleic anhydride-modified polypropylene.
Recycled asphalt is a mixture of recovered asphalt recovered from pavement waste material, a regeneration additive and / or a new replenishment asphalt, if necessary, with the addition of a supplemental agent and the like.

<Blending ratio>
The pavement binder of the present invention can use the above-mentioned polyamide resin alone or a mixture of a polyamide resin and asphalt.
When a mixture of a polyamide resin and asphalt is used, the compounding amount of the polyamide resin is 90% by mass or more, preferably 95% by mass, based on the total amount of the polyamide resin and asphalt from the viewpoint of improving crack resistance and workability. % Or more.
If the blending amount of the polyamide resin is less than 90% by mass, the elastic modulus and bending strength required at a high temperature (60 ° C.) may be insufficient.

[Paving mixture]
And the paving mixture of this invention contains the binder for paving of this invention, and an aggregate. As a result, a pavement mixture having high strength can be obtained, and the crack resistance can be improved.

<Aggregate>
Examples of aggregates that can be used for the pavement mixture include crushed stone, sand, screenings, stone powder, and recycled aggregates described in the Pavement Design and Construction Guidelines (Japan Road Association). Other aggregates such as ceramics can also be used. Further, a fiber reinforcing material, a pavement filler, and the like can be appropriately added to the aggregate.
As the aggregate, any of a coarse aggregate having a particle size of 2.36 mm or more and a fine aggregate having a particle size of less than 2.36 mm can be used. Examples of coarse aggregate include No. 7 crushed stone, No. 6 crushed stone, No. 5 crushed stone, and No. 4 crushed stone. Examples of the fine aggregate include river sand, hill sand, mountain sand, sea sand, crushed sand, fine sand, screenings, crushed dust, silica sand, artificial sand, glass cullet, foundry sand, and crushed recycled aggregate sand. . The fine aggregate may contain a filler such as sand, fly ash, calcium carbonate, slaked lime and the like.
Among these, a combination of coarse aggregate and fine aggregate is preferable.

<Blending ratio of aggregate and pavement binder>
The aggregate that can be used in the paving mixture is mixed with a paving binder in an amount suitable for the aggregate particle size. The amount of the pavement binder depends on the aggregate particle size and the aggregate material, but is preferably from 4% by mass to 8% by mass based on the total mass ratio of the pavement mixture.
The amount of binder for pavement can be determined according to the optimal asphalt amount required from the `` mixing design of asphalt composition '' described in `` Pavement Design and Construction Guidelines '' issued by the Japan Road Association. May be determined by the following method.

The pavement mixture may be used as a heated asphalt mixture containing substantially no water, or an asphalt emulsion is prepared by mixing an emulsifier or water with the pavement mixture, and an aggregate or the like is added thereto. It may be used as a mixture.
From the viewpoint of softening asphalt, the temperature at which the aggregate is mixed with the binder for paving is preferably 130 ° C. or higher, more preferably 140 ° C. or higher, and preferably 190 ° C. or lower, more preferably 180 ° C. or lower. .
The mixing time is preferably 1 minute or more, more preferably 2 minutes or more, and still more preferably 5 minutes or more. The upper limit of the time is not particularly limited, but is, for example, about 30 minutes.

[Asphalt pavement method]
In the asphalt pavement method using the pavement binder and the pavement mixture of the present invention, the pavement mixture can be compacted by the same construction machine knitting and construction system as a normal asphalt mixture.
When used as a heated asphalt mixture, the compaction temperature of the asphalt mixture is preferably at least 100 ° C., more preferably at least 120 ° C., even more preferably at least 130 ° C., and preferably at most 200 ° C., more preferably 180 ° C. ° C or lower, more preferably 170 ° C or lower.
The softening point of the polyamide resin constituting the binder for paving of the present invention is 60 ° C. or more and 105 ° C. or less, and the melt viscosity at 180 ° C. is 140 mPa · s or more and 500 mPa · s or less. And the durability of the pavement after construction can be improved.

Further, since the polyamide resin constituting the binder with the pavement mixture of the present invention does not dissolve in petroleum-based oil, it has excellent oil resistance compared to pavement using conventional petroleum asphalt for pavement. Pavements using the mixture are less likely to erode.
According to the pavement mixture of the present invention, from the viewpoint of high strength and excellent workability, it is also suitably used for pavement constructed on a floor slab of a bridge over a road. Strength can be imparted to the bridge structure. Also, since the construction can be completed in a short period of time, it is advantageous for repair work on bridges that cannot easily make a detour like a road.

In the following Production Examples, Examples and Comparative Examples, “parts” and “%” are “parts by mass” and “% by mass” unless otherwise specified.
In addition, about various physical properties, measurement and evaluation were performed by the following methods.

(1) Measurement of Softening Point of Polyamide Resin The softening point of the polyamide resin was measured by the ring and ball method described in “JIS K2207: 2006 Petroleum Asphalt”.
(2) Measurement of Melt Viscosity of Polyamide Resin The melt viscosity of the polyamide resin was measured at a test temperature of 180 ° C. in accordance with “Petroleum Institute of Japan Standard JPI-5s-54-99: Viscosity Test Method Using Asphalt-Rotation Viscometer”. Was measured.

(3) Measurement of Heat of Crystallization (ΔHc) of Polyamide Resin Using a differential scanning calorimeter “DSC Q20” (manufactured by TA Instruments Japan Co., Ltd.) according to JIS-K7121, a sample of 0.01 was used. ０．０0.02 g was weighed in an aluminum pan, the temperature was raised to 150 ° C. at a rate of temperature increase of 20 ° C./min, and the temperature was lowered to −10 ° C. at a rate of temperature decrease of 5 ° C./min to obtain a crystallization heat generation curve. . The calorific value was calculated from the area of the exothermic peak obtained from the crystallization exothermic curve, and defined as the heat of crystallization (ΔHc).

(4) Evaluation of workability The workability was evaluated based on the scoop workability during construction.
Using a mixture for pavement obtained by heating and melting and mixing a polyamide resin and sand at 150 ° C., workability when pavement was constructed with a scoop was determined according to the following criteria, and the workability was evaluated.
(Evaluation criteria)
：: Scoop workability is better than that of a general dense particle asphalt mixture.
X: The scoop workability is poor and the workability is poor as compared with a general dense particle asphalt mixture.
The dense particle asphalt mixture is a heated asphalt mixture composed of coarse aggregate, fine aggregate, and asphalt, and has a synthetic particle size of 2.5 to 50% through a 35 mm sieve.

(5) Evaluation of crack resistance A polyamide resin melted at 180 ° C. was poured into a metal mold and allowed to cool naturally to room temperature, and the resin was observed to evaluate the presence or absence of cracks.
The test was performed five times, and the average value was determined as follows.
(Evaluation criteria)
：: No cracking occurred.
○: Cracks of less than 1 mm occurred.
X: Cracks of 1 mm or more occurred.

(6) Measurement of the amount of shrinkage of polyamide resin The polyamide resin melted at 180 ° C is poured into a metal mold (inner length 15 cm x inner width 2 cm x inner depth 1.5 cm), and is naturally cooled and solidified to room temperature. Then, the maximum value of the distance between the metal mold and the contracted polyamide resin was measured as the amount of contraction of the polyamide resin.
The larger the amount of shrinkage, the more easily cracks are generated.

Production Example 1 (Production of polyamide resin A1)
Carboxylic acid components including oleic acid (manufactured by Kao Corporation, trade name: LUNAC O-V) and polymerized fatty acids (manufactured by Harima Chemicals, Inc., trade name: Haridimer 250), ethylenediamine (EDA) and hexamethylenediamine (HMDA) ) Was placed in a four-necked round-bottomed flask equipped with a thermometer, a stirring system, a dehydrating tube and a nitrogen blowing tube, and the mixture was stirred, and a slight amount of nitrogen was flown to prevent coloring of the contents. Thereafter, the mixture was reacted at 210 ° C. for 3 hours and further under reduced pressure (13.3 kPa) for 2 hours. After cooling, the mixture was pulverized to obtain a polyamide resin A.
Regarding the content ratio of each component, oleic acid was 0.19 mole equivalent (9.5 mole equivalent% based on all components) and 0.81 mole of polymerized fatty acid per mole equivalent of carboxylic acid component. Equivalent (40.5 mole equivalent% based on all components), and as for the amine component, 0.7 mole equivalent (35 mole equivalent% based on all components) of ethylenediamine (EDA) per mole equivalent of the amine component. , Hexamethylenediamine (HMDA) is 0.3 molar equivalent (15 molar equivalent% based on all components). The ratio between the carboxylic acid component and the amine component is 1.0 / 1.0 in molar equivalent ratio (carboxylic acid component / amine component).
The polyamide resin A had a softening point of 94.0 ° C., a melt viscosity of 180 ° C. of 175 mPa · s, and a heat of crystallization (ΔHc) of 3.97 J / g.

Production Example 2, Comparative Production Examples 1 to 4 (Production of polyamide resins A2, B1 to B4)
In Production Example 1, polyamide resins A2 and B1 to B4 were obtained in the same manner as in Production Example 1, except that the amine composition of the polyamide resin was changed as shown in Table 1. Table 1 shows the results.

Production Example 3 (Production of polyamide resin A3)
Carboxylic acid components including oleic acid (manufactured by Kao Corporation, trade name: Lunac O-V) and polymerized fatty acids (manufactured by Harima Chemicals, Inc., trade name: Haridimer 250), ethylenediamine (EDA), hexamethylenediamine (HMDA) ) And an amine component consisting of diethylenetriamine (DETA) are placed in a four-neck round bottom flask equipped with a thermometer, a stirring system, a dehydrating tube and a nitrogen blowing tube, and the mixture is stirred. After flowing nitrogen, the mixture was reacted at 210 ° C. for 3 hours and further under reduced pressure (13.3 kPa) for 2 hours, cooled, and pulverized to obtain a polyamide resin A3.
Regarding the content ratio of each component, oleic acid was 0.17 mole equivalent (8.5 mole equivalent% based on all components) and polymerized fatty acid was 0.83 mole per 1 mole equivalent of the carboxylic acid component. Equivalent (41.5 molar equivalents based on all components). For amine components, 0.54 molar equivalents of ethylenediamine (EDA) per mole equivalent of amine components (27 molar equivalents based on all components). , Hexamethylenediamine (HMDA) is 0.36 molar equivalents (18 molar equivalents based on all components), and diethylenetriamine (DETA) is 0.10 molar equivalents (5 molar equivalents based on all components). The ratio between the carboxylic acid component and the amine component is 1.0 / 1.0 in molar equivalent ratio (carboxylic acid component / amine component).
The softening point of the polyamide resin A3 was 83.4 ° C, the melt viscosity at 180 ° C was 190 mPa · s, and the heat of crystallization was 2.40 J / g.

Production Example 4, Comparative Production Examples 5 to 6 (Production of polyamide resins A4 and B5 to B6)
In Production Example 3, polyamide resins A4 and B5 to B6 were obtained in the same manner as in Production Example 3, except that the carboxylic acid composition of the polyamide resin was changed as shown in Table 1. Table 1 shows the results.

Example 1 (production of paving mixture)
A binder for pavement comprising 90% by mass of polyamide resin A1 and 10% by mass of straight asphalt and coarse aggregate having a maximum particle size of 13 mm were kneaded with a mixer at 150 ° C. for 2 minutes. The pavement mixture obtained was compacted at 110 ° C. Table 2 shows the results.
The compaction temperature is described in pavement construction manual (2006 edition, published by Japan Road Association). The lower limit of the initial compaction temperature of the asphalt mixture described in 112 was determined as a reference.

Examples 2 to 4, Comparative Examples 1 to 6
A pavement mixture was obtained and compacted at 110 ° C. in the same manner as in Example 1 except that the polyamide resin shown in Table 1 was used instead of the polyamide resin A1.
Table 2 shows the results.

From the results in Table 2, it can be seen that the paving mixture obtained in Examples 1 to 4 is excellent in workability and crack resistance after the construction as compared with the paving mixture obtained in Comparative Examples 1 to 6. .
When a polyamide resin having a melt viscosity of 140 mPa · s or more is used as in Examples 1 and 2, the obtained pavement mixture has excellent crack resistance while maintaining good workability. On the other hand, when a polyamide resin having a melt viscosity of 105 mPa · s (less than 140 mPa · s) is used as in Comparative Example 3, the resulting pavement mixture has excellent workability, but has poor crack resistance. This is considered to be due to an increase in the amount of crystals of the polymer.
1 and 2 are photographs showing the state of the pavement mixture obtained by kneading the polyamide resin A2 or B6, asphalt and aggregate at 150 ° C. for 2 minutes in Example 2 and Comparative Example 6, respectively. .
In Example 2 (see FIG. 1), it was found that the polyamide resin and the asphalt were uniformly dispersed in the aggregate, and the pavement binder composed of the polyamide resin and the asphalt was uniformly attached to the surface of the aggregate. It was good. On the other hand, in Comparative Example 6 (see FIG. 2), there were many places where the pavement binder did not adhere (the parts that looked white), and the adhesion of the pavement binder composed of polyamide resin and asphalt to the aggregate was uneven. Therefore, further kneading was necessary, and the workability was poor. Since it is necessary to open the traffic in the shortest possible time in the pavement work, it is required that the kneading be completed in a short time like the pavement mixture obtained in the example.

Claims (6)

A pavement binder which is used in combination with a polyamide resin alone or a mixture of a polyamide resin and asphalt, and is used in a pavement mixture.
The blending amount of the polyamide resin to be blended in the mixture is 90% by mass or more based on the total amount of the polyamide resin and asphalt;
The polyamide resin has a softening point of not less than 60 ° C. and not more than 105 ° C., and the melt viscosity at 180 ° C. of the polyamide resin is not less than 140 mPa · s and not more than 500 mPa · s,
The polyamide resin is a polycondensate of a carboxylic acid component and an amine component containing a polyamine, and the amine component is at least two of the same or different kinds selected from aliphatic diamines, aliphatic triamines, and aromatic diamines. A pavement binder comprising the above polyamine, wherein at least one is an aliphatic diamine, and the amount of the largest amount of the polyamine is from 51 mol% to 75 mol% with respect to the total amount of the amine.   The paving binder according to claim 1, wherein the greatest amount of polyamine species is an aliphatic diamine.   3. The pavement binder according to claim 1, wherein the polyamide resin is a polycondensate of a carboxylic acid component containing a monovalent carboxylic acid and a polymerized fatty acid and an amine component containing a polyamine. 4.   The pavement binder according to claim 3, wherein the content of the monovalent carboxylic acid in the carboxylic acid component is 5 mol% to 50 mol% based on the total amount of the carboxylic acid component.   The pavement binder according to any one of claims 1 to 4, wherein the polyamide resin has a heat of crystallization (ΔHc) obtained by differential scanning calorimetry (DSC) of 4.2 J / g or less.   A pavement mixture comprising the pavement binder according to any one of claims 1 to 5 and an aggregate.