JP2010121350A - Polyurethane composition for elastic pavement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane composition for elastic pavement with excellent long-term storage stability and foaming resistance while satisfying low-temperature work efficiency and curing property required for a resin binder used in a general in site elastic pavement material. <P>SOLUTION: The polyurethane composition 12 for elastic pavement contains an urethane prepolymer having carbodiimide group in a main chain and two or more isocyanate groups in a terminal, in which the mass% of the carbodiimide group to the mass of the urethane prepolymer is 1.5 mass% or more. An elastic pavement material 10 is obtained by solidifying the polyurethane composition 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyurethane composition for elastic paving.

2. Description of the Related Art Conventionally, as an elastic pavement material used for pavement on a road surface, a material obtained by solidifying (solidifying) an elastic aggregate such as a rubber chip obtained by pulverizing a rubber product such as an automobile waste tire with a resin binder is known.
Elastic paving materials including such elastic aggregates have a large amount of deflection with respect to the load compared to asphalt paving, and can provide a paved road surface with excellent shock absorption and safety during falls. Widely used. In addition, when used on a roadway, it is expected to develop an elastic pavement that is excellent in resilience, air permeability, and noise reduction effect due to sound absorption, and that hardly causes tire slippage when wet.

This elastic pavement material is roughly classified into two types. First, it is a type in which tile-shaped blocks having a side of 40 to 50 cm, which are prepared by curing a resin in advance at a factory, are spread on the road surface. Second, the resin composition is cured at the construction site.
The first type of elastic pavement has the advantage of shortening the working time, but has a problem that a gap is formed on a road surface with a curve or unevenness. On the other hand, the second type of elastic pavement material is called an on-site construction type elastic pavement material, and can be constructed without causing a gap even on a curved or uneven road surface. It is out.

As a resin binder used for the on-site construction type elastic pavement material, a one-component moisture-curable composition using a urethane prepolymer is widely used.
However, a one-component moisture-curable composition using a urethane prepolymer takes a long time to be completely cured, and there is a problem in applying it to pavements such as roadways where shortening of construction time is required. there were. In addition, there is a problem that durability such as adhesion to the substrate and chemical resistance is insufficient.

In order to solve such a problem, Patent Document 1 states that “a moisture curable polyurethane composition obtained by adding a tertiary amine catalyst to a urethane prepolymer having at least two isocyanate groups at its ends. Is proposed.
However, since the moisture-curable polyurethane composition described in Patent Document 1 is inferior in storage stability for a long time (for example, about 30 days), gelation and viscosity increase occur during storage, and poor mixing with elastic aggregates occurs. There was a problem that occurred. In addition, there is a problem that carbon dioxide generated due to curing of the urethane prepolymer is poor and foaming easily occurs.

JP-A-6-172706

  Therefore, the present invention provides a polyurethane for elastic paving that is excellent in long-term storage stability and foam resistance while satisfying low-temperature workability and curability required for resin binders used in general on-site construction type elastic paving materials. It is an object to provide a composition.

As a result of earnest research to solve the above problems, the present inventor has achieved low-temperature workability and curability by using a urethane prepolymer having a carbodiimide group in the main chain and two or more isocyanate groups at the terminals. The present inventors have found that an elastic paving polyurethane composition excellent in long-term storage stability and foam resistance can be obtained while satisfying the present invention.
That is, the present invention provides the following (1) to (7).

  (1) A polyurethane composition for elastic pavement containing a urethane prepolymer (A) having a carbodiimide group in the main chain and having two or more isocyanate groups at the terminal.

  (2) For elastic paving as described in (1) above, wherein the carbodiimide group mass% (hereinafter also referred to as “NCN%”) is 1.5 mass% or more with respect to the mass of the urethane prepolymer (A). Polyurethane composition.

  (3) The said isocyanate group mass% (henceforth "NCO%") with respect to the mass of the said urethane prepolymer (A) is 5.0 mass% or more, It is described in said (1) or (2). Polyurethane composition for elastic paving.

  (4) The polyurethane composition for elastic paving according to any one of (1) to (3), further comprising another urethane prepolymer (B).

  (5) The polyurethane composition for elastic paving as described in (4) above, wherein the carbodiimide group is 1.2% by mass or more based on the total mass of the urethane prepolymer (A) and the urethane prepolymer (B). object.

  (6) The elasticity as described in (4) or (5) above, wherein the mass% of the isocyanate group with respect to the total mass of the urethane prepolymer (A) and the urethane prepolymer (B) is 5.0% by mass or more. Polyurethane composition for paving.

  (7) An elastic paving material obtained by solidifying the polyurethane composition for elastic paving according to any one of (1) to (6).

As described below, according to the present invention, while satisfying the low-temperature workability and curability required for a resin binder used in a general on-site type elastic pavement material, long-term storage stability and resistance to foaming are achieved. It is possible to provide a polyurethane composition for elastic pavement having excellent properties.
Specifically, the polyurethane composition for elastic pavement of the present invention has a workability at about 5 ° C. or less and a curability at a low temperature to a normal temperature (about 5 to 25 ° C.) (particularly, an appropriate tack-free time). It is very useful because it is excellent in storage stability and foam resistance for about 30 days or more.

The present invention is described in detail below.
The polyurethane composition for elastic paving of the present invention (hereinafter simply referred to as “the polyurethane composition of the present invention”) has a urethane prepolymer having a carbodiimide group in the main chain and two or more isocyanate groups at the terminal (A Is a polyurethane composition for elastic paving.
Next, the urethane prepolymer (A) and other urethane prepolymer (B) which may be optionally contained will be described in detail.

<Urethane prepolymer (A)>
The urethane prepolymer (A) used in the polyurethane composition of the present invention is not particularly limited as long as it is a urethane prepolymer having a carbodiimide group in the main chain and two or more isocyanate groups at the terminals.
Here, the carbodiimide group means -N = C = N-, and the bond (single bond) of the nitrogen atom constitutes a part of the main chain.

  The urethane prepolymer (A) includes, for example, a carbodiimide-modified polyisocyanate compound (hereinafter simply referred to as “carbodiimide-modified polyisocyanate”) and a polyol compound with respect to a hydroxy group (OH group) as an isocyanate group (NCO group). The reaction product obtained by making it react so that may become excess can be used.

(Carbodiimide-modified polyisocyanate)
The carbodiimide-modified polyisocyanate used in the production of the urethane prepolymer (A) is obtained by carbodiimidizing a polyisocyanate compound.

The polyisocyanate compound is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Specific examples of the polyisocyanate compound include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI, and the like. (For example, 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene Hexamethyle aromatic polyisocyanates such as diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate; Aliphatic polyisocyanates such as diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanatomethyl) cyclohexane (H ₆ XDI), alicyclic polyisocyanates such as dicyclohexylmethane diisocyanate (H ₁₂ MDI); carbodiimide-modified polyisocyanates; isocyanurate-modified polyisocyanates; and the like.

Such polyisocyanate compounds can be used alone or in combination of two or more.
Among these, MDI, XDI, HDI, IPDI, and H ₁₂ MDI are preferable because they are inexpensive and easily available.

  The method for carbodiimidizing such a polyisocyanate compound is not particularly limited. For example, a method of reacting a polyisocyanate compound and carbodiimide at a high temperature, or 3-methyl-1-phenyl-2-phospholene-1- The method of making it react at room temperature using catalysts, such as an oxide, is mentioned.

Examples of the carbodiimide-modified polyisocyanate include compounds represented by the following formula (i).
^{OCN- (R 1 -N = C =} N) m -R 2 -NCO (i)

In formula (i), R ¹ and R ² are each independently a divalent aliphatic or alicyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms. M represents an integer of 1-20.
Examples of the divalent aliphatic or alicyclic hydrocarbon group having 1 to 10 carbon atoms of R ¹ include an alicyclic alkylene group which may be substituted with an alkylene group or an alkyl group, and an alkyl group. And an alkylene group and a vinylene group containing a heterocyclic ring. Specific examples include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, a p-methylenecyclohexane group, a p-dicyclohexylenemethylene group, a cyclohexylene group, and a morpholinoalkylene group.
Specific examples of the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms of R ¹ include a phenylene group, a phenylenebis (methylene) group, a p-xylylene group, and the like.

  Specific examples of the carbodiimide-modified polyisocyanate represented by the above formula (i) include compounds represented by the following formula.

(Polyol compound)
The polyol compound used in the production of the urethane prepolymer (A) is not particularly limited as long as it has two or more hydroxyl groups.
Examples of the polyol compound include polyether polyols, polyester polyols, other polyols, and mixed polyols thereof.

  Examples of the polyether polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1, Polyols obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide to at least one selected from the group consisting of 4-butanediol and pentaerythritol, etc. Is mentioned. Specifically, polyoxyethylene polyol and polyoxypropylene polyol are preferably exemplified.

  Specifically, the polyester polyol is selected from the group consisting of, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. A condensation polymer of at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, dimer acid, other aliphatic carboxylic acids and oligomeric acids; Ring-opening polymers such as lactone and valerolactone; and the like.

  Specific examples of other polyols include, for example, polymer polyol, polycarbonate polyol; polybutadiene polyol; hydrogenated polybutadiene polyol; acrylic polyol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, And low molecular weight polyols such as hexanediol.

Such polyol compounds can be used alone or in combination of two or more.
Among these, the polyoxyethylene polyol and the polyoxypropylene polyol are because the workability at low temperature of the polyurethane composition of the present invention obtained by using the obtained urethane prepolymer (A) becomes better. preferable.

  In the present invention, the amount of the carbodiimide-modified polyisocyanate and the polyol compound in producing the urethane prepolymer (A) is such that the NCO group / OH group (equivalent ratio) is 1.5 to 4.5. Preferably, it is 3 to 4.5. When the equivalent ratio is in such a range, the workability at low temperatures of the polyurethane composition of the present invention obtained using the urethane prepolymer (A) obtained is further improved.

  Moreover, in this invention, the manufacturing method of a urethane prepolymer (A) is not specifically limited, For example, it manufactures by heat-stirring the carbodiimide modified polyisocyanate and polyol compound of the above-mentioned equivalent ratio at 50-130 degreeC. can do. Moreover, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

In the present invention, by using such a urethane prepolymer (A), the resulting polyurethane composition of the present invention has good low-temperature workability and curability, and long-term storage stability and foam resistance.
The reason why the low temperature workability is good in this way is considered that such a urethane prepolymer (A) is generally liquid at normal temperature and has a small increase in viscosity at low temperature.
The reason why the curability is good will be described using the urethane prepolymer (A) exemplified by the following formula (1). When the carbodiimide group in the main chain skeleton of the following formula (1) is It reacts to form a urea bond (see formula (2)), this urea binding site functions as a catalyst, promotes the reaction between NCO and moisture (see formula (3)), and this reaction activates a tertiary amine catalyst. It is thought that this is because it proceeds relatively gently as compared to the case of using it.
Furthermore, the reason why the long-term storage stability and foaming resistance are good is considered to be that curing proceeds without using a separately added catalyst (for example, a tertiary amine described in Patent Document 1). .

In the present invention, the mass% (NCN%) of the carbodiimide group with respect to the mass of the urethane prepolymer (A) is preferably 1.5% by mass or more because the curability is better. 2.0% by mass or more, more preferably 3.0 to 4.5% by mass.
In addition, when it contains the urethane prepolymer (B) mentioned later, the mass% of the said carbodiimide group is the same reason with respect to the total mass of the said urethane prepolymer (A) and the said urethane prepolymer (B). 1.2 mass% or more is preferable, and 2.5 to 3.7 mass% is more preferable.

Furthermore, in the present invention, the mass% (NCO%) of the isocyanate group relative to the mass of the urethane prepolymer (A) is 5.0% by mass or more because the low-temperature workability is better. Preferably, it is 5 to 10% by mass.
In addition, when it contains the urethane prepolymer (B) mentioned later, the value of the mass% of the said isocyanate group is a value with respect to the total mass of the said urethane prepolymer (A) and the said urethane prepolymer (B).

<Urethane prepolymer (B)>
The polyurethane composition of the present invention may contain other urethane prepolymer (B) in addition to the urethane prepolymer (A).

A conventionally well-known thing can be used for the said urethane prepolymer (B) like a normal one-pack type polyurethane resin composition. For example, a reaction product obtained by reacting a polyisocyanate compound and a polyol compound such that an isocyanate group (NCO group) is excessive with respect to a hydroxy group (OH group) can be used.
Moreover, the said urethane prepolymer (B) can contain 0.5-5 mass% NCO group in a molecular terminal.
Here, as the polyisocyanate compound and the polyol compound, those described in the urethane prepolymer (A) can be used, respectively, and the same kind as that used in the urethane prepolymer (A) from the viewpoint of compatibility. It is preferable to use one.

  The polyurethane composition of the present invention may be added to other additives such as fillers, plasticizers, thixotropic agents, silane coupling agents, pigments, dyes, aging, as long as the purpose of the present invention is not impaired as necessary. An inhibitor, an antioxidant, an antistatic agent, a flame retardant, a drying oil, an adhesion-imparting agent, a dispersant, a dehydrating agent, an ultraviolet absorber, a solvent, and the like can be contained.

Examples of the filler include organic or inorganic materials of various shapes, such as calcium carbonate, carbon black, silica (white carbon), clay talc, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, quick lime, Carbonates (eg, magnesium carbonate, zinc carbonate, pepper), alumina hydrate (eg, hydrous aluminum hydroxide), diatomaceous earth, barium sulfate (eg, precipitated barium sulfate), mica, alumina sulfate, lithopone, asbestos, Graphite, molybdenum disulfide, pumice powder, glass powder, silica sand, zeolite; surface treated products of these fatty acids, resin acids, fatty acid esters, higher alcohol addition isocyanate compounds, etc .; glass balloons; resin balloons;
Of these, use of calcium carbonate is preferable from the viewpoint of workability and cost.

Examples of the plasticizer include tetrahydrophthalic acid, azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid and derivatives thereof; And polyester, polyether, epoxy, paraffin, naphthene and aromatic process oils.
Of these, ester plasticizers such as phthalic acid plasticizers and adipic acid plasticizers are preferred.

Specific examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.), disparon (manufactured by Enomoto Kasei Co., Ltd.), and the like.
Specific examples of the silane coupling agent include trimethoxyvinylsilane, γ-glycidoxypropyltrimethoxysilane, and the like.

Examples of the pigment include inorganic pigments and organic pigments.
Specific examples of inorganic pigments include, for example, zinc white, titanium oxide, dial, chrome oxide, iron black, composite oxides (for example, titanium yellow, zinc-iron brown, titanium / cobalt green, cobalt green). , Cobalt blue, copper-chromium black, copper-iron black), etc .; chromates such as chrome lead, molybdate orange; ferrocyanides such as bitumen; cadmium yellow, cadmium red, zinc sulfide, etc. Sulfides; sulfates such as barium sulfate; hydrochlorides; silicates such as ultramarine blue; carbonates such as calcium carbonate; phosphates such as manganese violet; hydroxides such as yellow iron oxide; carbons such as carbon black; Metal powder such as aluminum powder and bronze powder; titanium-coated mica;

  Specific examples of organic pigments include monoazo lakes (for example, Lake Red C, Permanen Red 2B, Brilliant Carmine 6B), monoazo (for example, Toluidine Red, Naphthol Red, Fast Yellow G, Benzimidazole Bordeaux). Benzimidazolone brown), disazo series (for example, disazo yellow AAA, disazo yellow HR, pyrazolone red), condensed azo series (for example, condensed azo yellow, condensed azo red, condensed azo brown), metal complex azo series (for example, nickel azo yellow) Azo pigments such as: copper phthalocyanine blue, copper phthalocyanine green, brominated copper phthalocyanine green, and other phthalocyanine pigments; dyes such as basic dye lakes (for example, rhodamine 6 lake); anthraquinone (examples) For example, flavanthrone yellow, dianthraquinolyl red, indanthrene blue), thioindigo (eg, thioindigo Bordeaux), perinone (eg, perinone orange), perylene (eg, perylene scarlet, perylene red, perylene) Maroon), quinacridone series (eg, quinacridone red, quinacridone magenta, quinacridone scarlet), dioxazine series (eg, dioxazine violet), isoindolinone series (eg, isoindolinone yellow), quinophthalone series (eg, quinophthalone yellow), Condensed polycyclic pigments such as isoindoline (for example, isoindoline yellow) and pyrrole (for example, pyrrole red); metal complex azomethine such as copper azomethine yellow; aniline black; daylight fluorescence Fee; and the like.

Specific examples of the dye include direct dyes, vat dyes, sulfur dyes, naphthol dyes, acid dyes, and disperse dyes.
Specific examples of the antioxidant include N, N′-diphenyl-p-phenylenediamine (DPPD), N, N′-dinaphthyl-p-phenylenediamine (DNPD), 2,2,4-trimethyl- Examples include 1,3-dihydroquinoline (TMDQ), N-phenyl-1-naphthylamine (PAN), and hindered phenol compounds.
Specific examples of the antioxidant include hindered phenol compounds such as butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA); triphenyl phosphite: and the like.
Specific examples of the antistatic agent include ionic compounds such as quaternary ammonium salts and amines; hydrophilic compounds such as polyglycols and ethylene oxide derivatives; and the like.
Specific examples of the flame retardant include chloroalkyl phosphate, dimethylmethylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, diethylbishydroxyethylaminophosphate, neopentyl bromide polyether, brominated polyether, and the like. It is done.
Specific examples of the drying oil include linseed oil, soybean oil, dehydrated castor oil, and tung oil.

Specific examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and various silane coupling agents.
Specific examples of the dispersant include fatty acid metal salts such as calcium stearate, magnesium stearate, lithium stearate, zinc stearate, aluminum stearate, calcium linoleate, magnesium hydroxystearate; ethyl stearate, lauric acid And fatty acid esters such as ethyl, butyl oleate, dioctyl adipate, and monoglyceride stearate;
Specific examples of the dehydrating agent include methyl stearoxypolysiloxane.
Specific examples of ultraviolet absorbers include, for example, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, hindered phenol ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and oxalic acid. Examples include anilide ultraviolet absorbers, formamidine ultraviolet absorbers, triazine ring ultraviolet absorbers, and nickel complex ultraviolet absorbers.
Specific examples of the solvent include hydrocarbons such as hexane and toluene; halogenated hydrocarbons such as tetrachloromethane; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; ethyl acetate. And ester systems such as

The method for producing the polyurethane composition of the present invention is not particularly limited. For example, the urethane prepolymer (A) and the urethane prepolymer (B) which may be optionally added and various additives are mixed, a roll, It can be produced by sufficiently mixing and uniformly dispersing (kneading) at room temperature or under heating (40 to 60 ° C., for example, 40 ° C.) using a kneader, an extruder, a universal stirrer, or the like.
When the urethane prepolymer (B) is contained, the carbodiimide-modified polyisocyanate used for the production of the urethane prepolymer (A) and the polyisocyanate compound used for the production of the urethane prepolymer (B). And the above polyol compound may be mixed at the same time and allowed to react.

The elastic pavement material of the present invention can be obtained by applying the polyurethane composition of the present invention on a base and solidifying it.
FIG. 1 is a schematic cross-sectional view showing an example of an elastic paved road in which the elastic paving material of the present invention is laid.
As shown in FIG. 1, an elastic pavement 10 is laid on a base 14 provided on the ground 15 with a predetermined thickness. The elastic pavement 10 is prepared by appropriately mixing organic aggregates and / or inorganic aggregates 11 according to the application, and applying a composition for elastic pavement using the polyurethane composition 12 of the present invention as a binder thereto. It is configured by solidifying.

  Specifically, the base includes, for example, known hard or soft bases such as concrete, mortar, asphalt concrete, wood board, and synthetic resin, and so-called roadbed layers such as a crushed stone layer and a chestnut layer.

Examples of the organic aggregate include chips such as various rubbers, synthetic resins, wooden pieces, and corks.
Specific examples of the rubber chip include natural rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, polyurethane rubber, EPDM, and the like, and those obtained by pulverizing waste tires as industrial waste from the viewpoint of economy. Is preferred. The shape of the rubber pulverized product is preferably granular or a hijiki having a certain length. The particle size is preferably 1 mm or more, more preferably 2 to 6 mm.
As a synthetic resin chip | tip, it is the concept containing the granular material obtained from various synthetic resin materials other than said rubber chip | tip. Specific examples include automobile bumpers and golf ball pulverized products.

Specific examples of the inorganic aggregate include natural stones such as mountain gravel and river gravel, and granular materials such as cryolite, quartz sand, artificial stone, slag, ceramics, and metal powder.
Among these, silica sand granule is suitable from the viewpoint of cost.
The inorganic aggregate is intended to improve the strength and abrasion resistance of the completed pavement and to improve the anti-slip property by being exposed on the surface. A particle diameter of 1 mm or more, particularly 2 to 10 mm, is suitable, but it is more effective when a fine aggregate having a particle diameter of 5 mm or less is mixed with 10 volume% or more of the inorganic material used.

Below, the construction method on the base | substrate of the polyurethane composition of this invention is demonstrated.
The polyurethane composition of the present invention is preferably added to a place where organic aggregates and / or inorganic aggregates are mixed with a mixer or the like.
The compounding ratio (volume ratio) ((1) / (2)) of (1) organic aggregate and / or inorganic aggregate and (2) the polyurethane composition of the present invention can be appropriately selected depending on the application.
For example, 9/1 to 6/4 is suitable for sidewalks, and 9/1 to 7/3 is particularly suitable. Also, 9 / 1-6 / 4 for track and field, 9 / 1-6 / 4 for jogging track, 9 / 1-7 / 3 for tennis court, 9/1 for soccer field -5/5, 9 / 1-5 / 5 are suitable for other multipurpose grounds. When used on a roadway, 9/1 to 6/4 is suitable for (1) / (2), and 8/2 to 6/4 is particularly suitable. For example, 8/2 to 6/4 is suitable for use on a highway.

Although the addition method of the polyurethane composition of this invention will not be specifically limited if it is a method which can adhere uniformly to an organic aggregate or an inorganic aggregate, For example, a spray method, a dripping method, etc. are mentioned.
The temperature at the time of addition of the polyurethane composition of the present invention may be room temperature, but the temperature can be adjusted as necessary from the viewpoint of adjusting the curing rate.

  Moreover, when it is calculated | required on scenery that pavement is colored, it can color by mixing a pigment with the polyurethane composition of this invention. The compounding amount of the pigment in that case is preferably 1.5 to 8 parts by mass with respect to 100 parts by mass of the urethane prepolymer (A). In addition, a colored material can also be used as an organic aggregate or an inorganic aggregate. Examples thereof include rubber such as EPDM, synthetic resin, and color chips such as artificial stone.

  In addition, the polyurethane composition of the present invention has a predetermined thickness (about 1-2 cm for sidewalks, about 2-3 cm for roadways, stadiums) on a base surface such as asphalt or concrete using a smoother or finisher. For about 1 to 3 cm) and solidify at room temperature to lay an elastic pavement. If necessary, a base primer treatment can be performed before laying the polyurethane composition of the present invention. As the primer, in addition to the TMXDI prepolymer, an MDI prepolymer or a TDI prepolymer is suitable.

  The paved road surface laid with the elastic pavement of the present invention can adjust the mixing ratio of organic aggregate and inorganic aggregate, and can increase the shock absorption by blending more organic aggregate for sidewalk use, For roadways, more inorganic aggregates are blended than for sidewalks, and the balance of noise reduction, vehicle handling stability and wear resistance can be adjusted.

  Moreover, since the elastic pavement material of the present invention is excellent in adhesiveness to the base and has a good balance between the curing speed of the resin binder and the storage stability, the work efficiency during construction is good.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Preparation of polyurethane resin>
The carbodiimide-modified polyisocyanate used for the production of the urethane prepolymer (A) and the polyisocyanate compound used for the production of the urethane prepolymer (B) and the polyol compound are mixed and reacted in the parts by mass shown in Table 1. A polyurethane resin was prepared. The final NCO% and NCN% were as shown in Table 1.

The following components were used as the components in Table 1.
-Carbodiimide-modified polyisocyanate: Carbodiimide-modified MDI (Luprinate MW-103, manufactured by BASF INOAC polyurethane)
Polyisocyanate compound: MDI (Cosmonate PH, manufactured by Mitsui Takeda Chemical Company)
Polyol compound: PPG (D-2000, manufactured by Asahi Glass Co., Ltd.)
Tertiary amine: bis (2-morpholino) diethyl ether (U-CAT660M, manufactured by San Apro)

(Examples 1-10 and Comparative Examples 1-4)
The polyurethane resin obtained above, aggregate (silica sand, average particle size: 2.2 mm), and particle size rubber (800H, particle size: 0.5 to 3 mm, manufactured by Misawa Toyo Co., Ltd.) are shown in Table 2 below. Each resin composition was obtained by mixing at a mass ratio.

  The obtained resin compositions were measured and evaluated for the low temperature workability and curability, long-term storage stability, and foam resistance by the measurement methods shown below. The results are shown in Table 2 below.

<Low temperature workability>
The low temperature workability was evaluated by the ease of mixing when the polyurethane resin obtained above, the aggregate and the particle size rubber were mixed at 5 ° C.
Those that were easy to mix were evaluated as “◯” as being excellent in low-temperature workability, and those that were difficult to mix were evaluated as “x” as being poor in low-temperature workability.

<Curing property>
Each obtained resin composition was subjected to a tack-free time (minutes) at 20 ° C. and 60% RH (relative humidity) in accordance with the tack-free test described in JIS A1439: 2004 “Testing methods for building sealing materials”. Was measured.
As a result, if the tack free time is within 150 minutes, it can be evaluated that the curability is excellent, and if the tack free time is more than 150 minutes within 200 minutes, it can be evaluated that there is no problem in practical curing. If the free time exceeds 200 minutes, it can be evaluated that the curability is inferior.

<Long-term storage stability>
After mixing the polyurethane resin obtained above in an airtight container, the above-mentioned aggregate, and the above-mentioned particle size rubber, the appearance after storing for 1 day at 80 ° C. for 30 days was visually confirmed.
As a result, it was evaluated as `` ○ '' as having excellent long-term storage stability immediately after mixing and with no change in appearance, and `` × '' as gelling and cloudy inferior to long-term storage stability It was evaluated.

<Foaming resistance>
The presence or absence of foaming after applying each resin composition obtained under the conditions of 20 ° C. and 60% RH (relative humidity) was visually confirmed.
As a result, a case where a large number of foaming was observed was evaluated as “x” as being poor in foaming resistance, and a case where foaming was not observed or extremely small was evaluated as “◯” as being excellent in foaming resistance.

  From the results shown in Table 2 above, the polyurethane compositions (Examples 1 to 10) containing the urethane prepolymer (A) prepared using a carbodiimide-modified polyisocyanate satisfy the low temperature workability and curability, It was found to be excellent in long-term storage stability and foam resistance.

FIG. 1 is a schematic cross-sectional view showing an example of an elastic paved road in which the elastic paving material of the present invention is laid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic pavement road 10 Elastic pavement material 11 Organic aggregate and / or inorganic aggregate 12 Polyurethane composition of this invention 14 Base 15 Ground

Claims (7)

  A polyurethane composition for elastic paving comprising a urethane prepolymer (A) having a carbodiimide group in the main chain and having two or more isocyanate groups at the terminal.   2. The polyurethane composition for elastic paving according to claim 1, wherein a mass% of the carbodiimide group with respect to a mass of the urethane prepolymer (A) is 1.5 mass% or more.   The polyurethane composition for elastic paving according to claim 1 or 2, wherein a mass% of the isocyanate group with respect to a mass of the urethane prepolymer (A) is 5.0 mass% or more.   Furthermore, the polyurethane composition for elastic paving according to any one of claims 1 to 3, further comprising another urethane prepolymer (B).   The polyurethane composition for elastic paving according to claim 4, wherein a mass% of the carbodiimide group with respect to a total mass of the urethane prepolymer (A) and the urethane prepolymer (B) is 1.2 mass% or more.   The polyurethane composition for elastic paving according to claim 4 or 5, wherein a mass% of the isocyanate group with respect to a total mass of the urethane prepolymer (A) and the urethane prepolymer (B) is 5.0 mass% or more.   The elastic pavement material which solidifies the polyurethane composition for elastic pavements in any one of Claims 1-6.

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