JP5047484B2 - A caking agent for preventing crushed stone from crushed stone and a method for stabilizing the basin using the same - Google Patents

Description

  The present invention has a low odor, excellent foam suppression, has a viscosity that can be easily sprayed even at low temperatures, and has a performance that can be cured in a short time even at low temperatures. The present invention relates to an agent and a method for stabilizing a bed using the same.

  Generally, the railroad track bed is composed of rails, sleepers, and crushed stone (ballast). Ballast is a crushed stone on the track to prevent and stabilize sleepers and rails, but the ballast may be scattered by the vibration of the train and the wind pressure when passing. Since the speed of trains is increasing, it is required to prevent harm to the car body and houses along the line due to ballast scattering.

  In order to prevent such scattering, a vinyl acetate emulsion or urethane resin is sprayed and cured on the ballast to prevent scattering. In emulsions and the like, the water resistance is low, resulting in a decrease in mechanical strength and a decrease in long-term ballast fixing ability, and frequent reworking is required to preserve it.

In addition, with regard to the construction (spraying and hardening) of the ballast sticking agent, the sticking agent must be sprayed onto the crushed stone by rain dew at night when the train does not pass, and hardening must be completed before the first train passes. The caking agent is required to have workability and curability at low temperatures. That is, in winter such as 0 ° C., it can be sprayed with rain dew and used within 2 hours until curing. In order to satisfy this requirement, a high-molecular-weight prepolymer having a high viscosity is often used to improve the reactivity in a caking agent made of a one-component moisture-curable urethane resin, but the viscosity is lowered to ensure workability. Therefore, a low-boiling point solvent, a high-boiling point solvent, and a roadbed stabilizer to which a plasticizer is added have been proposed (see, for example, Patent Documents 1, 2, 3, and 4).
However, these additives suffer from odor and toxicity, and low flash point. In particular, those that have an impact on safety and environmental pollution have become unusable in recent years. Further, in order to reduce the viscosity, the urethane resin may be used by heating, or the resin may be sprayed with a high-pressure sprayer, but there is a problem that the construction is large and time-consuming and is dangerous. On the contrary, in the case of curing at high temperature and high humidity in the summer or by addition of water, the curing is fast, but at the same time, the curing occurs with the foaming of urethane, so that there is a problem that the ballast is moved by the foaming.
Further, there has been proposed a caking stone caking agent to which a plasticizer or an aliphatic high-boiling solvent is added in order to reduce the viscosity, although the surface hardening is fast but the internal hardening is slow (see, for example, Patent Document 5). However, there is a risk that whitening occurs at low temperatures.
JP-A-8-157502 JP 2001-19732 A JP 2001-106899 A JP-A-11-322880 JP 2003-192888 A

  The purpose of the present invention is to form a coating film with low viscosity and low odor throughout the year, with stable curability and adhesion that is hardly affected by temperature and humidity, almost no odor, and good flammability and toxicity. Another object of the present invention is to provide a caking agent for preventing pulverized crushed stone and a method for stabilizing the basin using the same.

As a result of diligent research to solve such problems, the present inventors can solve the above problems by using a urethane prepolymer using a polyol having a polyethylene oxide chain as a polyol and a specific thinning agent. In order to discover what can be done, the present invention has been completed.
That is, the present invention comprises a terminal isocyanate group-containing urethane prepolymer (A) obtained by reacting a polyol having a polyethylene oxide chain in the molecule with an organic polyisocyanate compound, and an alkyl monocarboxylic acid-modified hydroxyl group as a thickener. A caking agent for roadbed crushed stone having a higher fatty acid ester (B) as a main component and a viscosity at 25 ° C. of 500 mPa · s or less, and the amount of the polyethylene oxide chain is 10 to 25% by weight in the polyol. The present invention relates to a caking agent for roadbed crushed stone and a method for stabilizing the roadbed using the same.

  The caking agent for preventing crushed stone of the present invention has almost no odor, good flammability and toxicity, low viscosity at low temperature, and can be sprayed in rain dew, and within 2 hours after spraying. It can be cured, and can form a coating film having stable curability and adhesion that is hardly affected by temperature and humidity and rainwater throughout the year.

  The terminal isocyanate group-containing urethane prepolymer (A) used in the present invention is obtained from a polyol and an organic polyisocyanate compound, and may contain an unreacted organic polyisocyanate compound. However, specifically, an unreacted organic polyisocyanate compound can be contained in an amount of 70% by weight or less, preferably 60% by weight or less. The urethane prepolymer (A) preferably has a viscosity at 25 ° C. of preferably 100 to 10,000 mPa · s, more preferably 500 to 5000 mPa · s.

  The organic polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups, and is an aromatic, aliphatic, or alicyclic polyisocyanate compound, a mixture of two or more thereof, And any of modified polyisocyanates obtained by modifying them. For example, polyisocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, polymeric MDI (crude MDI) and their modified polyisocyanates such as carbodiimide modified products, burettes Examples include modified products, dimers, trimers, and the like, and examples include terminal isocyanate group prepolymers of these polyisocyanates and active hydrogen-containing compounds. Polymeric MDI is preferred.

In addition, the polyol used in the present invention has a whitening effect at low temperatures by adding DOA (dioctyl adipate) or an aliphatic high-boiling solvent, etc., in order to accelerate internal curing and when used together with a thinning agent. In order to eliminate this, the polyethylene oxide chain contains 10 to 25% by weight. When the content of the polyethylene oxide chain is less than 10% by weight, whitening of the coating film is likely to occur at a low temperature, whereas when it exceeds 25% by weight, foaming tends to occur and the strength of the cured product is lowered. Among these, it is preferable that a polyethylene oxide chain is 15 to 20 weight% in a polyol.
Examples of the polyol include polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, glycerin, trimethylolpropane, triethylolethane, 1,3,6-hexanetriol, pentaerythritol, bisphenol A, and novolak, And / or those polyhydroxy compounds obtained by addition polymerization of ethylene oxide so as to form an ethylene oxide chain in the above-mentioned range. In addition to ethylene oxide, alkylene oxides such as propylene oxide can be used within a range not departing from the object of the present invention.
In addition, the polyol used can be used alone, as well as an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with other isocyanate groups, and as a specific example, Examples thereof include polyester polyol, polycaprolactone polyol, polybutadiene polyol, acrylic polyol, and higher fatty acid ester polyol.

  In addition, as compounds that can be used in combination as part of polyol, alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine, compounds containing two or more active hydrogens such as ethylenediamine, diethylenetriamine, triethylenetetramine, and toluenediamine and / or Examples of these amines include those obtained by addition polymerization of ethylene oxide, propylene oxide and the like.

  The equivalent ratio of the organic polyisocyanate to the polyol in the terminal isocyanate group-containing urethane prepolymer (A) component is preferably 1.5 equivalents or more in terms of isocyanate groups with respect to 1 equivalent of hydroxyl groups of the active hydrogen compound containing polyol.

  In the present invention, an alkyl monocarboxylic acid-modified hydroxyl group-containing higher fatty acid ester is used as the viscosity reducing agent (B). Such a thinning agent is liquid at room temperature, is compatible with the component (A) and exhibits a viscosity reducing action when added to the component (A), and is a higher (un) saturated fatty acid ester having a hydroxyl group. The hydroxyl group is modified with an alkyl monocarboxylic acid. In particular, a compound represented by the following general formula (1) is preferable, and a compound having a flash point of 200 ° C. or more and a viscosity of 100 mPa · s or less (25 ° C.) is most preferable.

(In the formula, X: an alkyl group having 1 to 6 carbon atoms Y: an alkyl group having 1 to 6 carbon atoms n: an integer 3 to 7 m: an integer 4 to 10)

As those such alkyl monocarboxylic acid-modified hydroxyl group-containing representative of a higher fatty acid ester, etc. For example acetylation of ricinoleic acid ester and the like.

  In the present invention, the mixing ratio of the urethane prepolymer (A) and the viscosity reducing agent (B) is not particularly limited as long as the effect of the present invention is achieved, but the weight ratio of (A) / (B) is Preferably it is 20 / 80-60 / 40, More preferably, it is 30 / 70-50 / 50.

  In the above-mentioned viscosity reducing agent (B), a part of the viscosity reducing agent can be substituted with a known high flash point plasticizer or other fatty acid ester within a range not impairing the effects of the present invention. Examples of such plasticizers include known plasticizers such as di-2-ethylhexyl phthalate, diisononyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, trimellitic acid ester, di-2-ethylhexyl adipate, and sebacate-di-2-ethylhexyl. Further, it may be a mixture of two or more of phosphate esters such as trimethyl phosphate and tris (2-ethylhexyl) phosphate, and fatty acid esters such as palm fatty acid methyl, lauric acid methyl and isopropyl myristate.

  It is preferable to use together the curing catalyst (C) of the terminal isocyanate group-containing urethane prepolymer (A) in the caking agent of the present invention. As the curing catalyst (C), a moisture curing catalyst is particularly preferable. For example, N, N, N ′, N′-tetramethylhexamethylenediamine, N, N, N ′, N′-tetramethylpropylenediamine, N, N , N ′, N′-pentamethyldiethylenetriamine, N, N, N ′, N′-tetramethylethylenediamine, N-methyl-N′-dimethyl-aminoethylpiperazine, N, N-dimethylaminocyclohexylamine, bis (dimethyl Aminoethyl) ether, tris (N, N-dimethylaminopropyl) hexahydro-s-triazine, methylmorpholine, ethylmorpholine, dimorphodiethylether, ditriethylenediamine, triethanolamine-1-methylimidazolol, 1,2 -Dimethyl imidazole, 1-isobutyl-2-methyl imidazole And the like, in particular di-morpholinium diethyl ether. These can be used alone or as a mixture of two or more. In addition, the following amine catalyst and metal catalyst are used as a catalyst for assisting the reaction between the active hydrogen-containing functional group and the isocyanate group. Examples include stannous octoate, dibutyltin dilaurate, dibutyltin diacetate, tin (II) octoate, lead octoate, potassium octylate, lead octylate, and potassium acetate. These can be used alone or as a mixture of two or more. In addition, 0.05-5 weight% is suitable for the usage-amount of this hardening catalyst (C) with respect to a terminal isocyanate group containing urethane prepolymer (A).

  In addition, auxiliary agents and / or additives may be added to the caking agent of the present invention as necessary. For example, weathering stabilizers, fillers, dyes, pigments, hydrolysis inhibitors, fungicides And bactericides, flame retardants, etc.

  In the present invention, (A) and (B), or (C) or the like may be mixed in advance or may be divided and mixed on site if necessary.

  The viscosity of the caking agent of the present invention is 500 mPa · s or less, preferably 100 to 500 mPa · s at 25 ° C. When the viscosity is higher than 500 mPa · s, there is a problem that the caking agent cannot be sprayed due to rain dew.

  The caking agent of the present invention has a low viscosity, low odor, can form a coating with stable curability and adhesion that is hardly affected by temperature and humidity, has almost no odor, and has good flammability and toxicity. In addition, since the flash point is substantially 200 ° C. or higher, it is extremely safe, and since the viscosity is 500 mPas or less, the workability is also excellent. That is, since a thickening agent having a flash point of 200 ° C. or higher in the atmosphere can be used, the flash point of the entire roadbed binder becomes 200 ° C. or higher. It corresponds to 4 petroleums (at 200 ° C or higher in the atmosphere), and can exhibit the merit that the storage quantity of the caking agent of the present invention can be greatly increased as compared with the conventional dangerous materials type 4 and type 3 petroleums. . Furthermore, since the viscosity reducing agent used in the present invention is very safe, even if it is eluted with rain water or the like, there is almost no influence on environmental pollution.

  The caking agent of the present invention is for caking the ballast used for the road bed. The roadbed is a so-called railroad track bed and is composed of rails, sleepers, and ballasts. Such ballast is on the track to prevent and stabilize sleepers and rails from bending and moving. By consolidating the ballast with the caking agent of the present invention, it is possible to prevent the ballast from being scattered due to train vibration or wind pressure during passage. In recent years, since the speed of trains has been increased, preventing ballast from being scattered prevents damage to the car body and houses along the railway line.

Next, the road bed stabilization method of the present invention will be described. That is, the road bed stabilization method of the present invention is to spray the road bed crushed stone caking agent on the crushed stone of the road bed.
The method for spraying the caking agent for the roadbed crushed stone to the crushed stone (ballast) may be any method that can be applied to the ballast, and for example, it can be carried out using rain dew spraying or a spray coating machine. The application amount is preferably 0.1 to 5 kg per 1 m 2 of the road bed. The ballast is preferably crushed stone having an average particle size of about 3 to 200 mm.

  EXAMPLES Next, although an Example, a comparative example, etc. are given and this invention is demonstrated in detail, this invention is not limited to this Example. In the examples and comparative examples, “part” and “%” mean “part by weight” and “% by weight”. The raw materials used in the examples and comparative examples are shown below.

Reference Example 1 (Synthesis of Prepolymer A)
In a 1-liter flask, DP-2000 [polyoxypropylene diol with a number average molecular weight of 2000, trade name, manufactured by Dainippon Ink & Chemicals, Inc.] 200 g and ED-36 [copolymer of polyethylene oxide with a number average molecular weight of 2000 and polyoxypropylene diol] Polymer Polyethylene oxide chain amount 80% Mitsui Takeda Co., Ltd.] 100 g, Hyprox TG-3009 [average molecular weight 4000 polyoxypropylene triol, Dainippon Ink & Chemicals, Inc. trade name] 100 g MDI (BASFINOAC polyurethane Co., Ltd. product M-5S) 450g was added and reacted, and the urethane prepolymer was obtained. This urethane prepolymer had 14.7% isocyanate groups. The amount of polyethylene oxide in the polyol was 20%.

Reference Example 2 (Synthesis of Prepolymer B)
To a 1 liter flask, 225 g of DP-2000, 75 g of ED-36, and 100 g of Hyprox TG-3009 were added with 450 g of MDI (M-5S manufactured by BASFINOAC Polyurethane Co., Ltd.) to obtain a urethane prepolymer. This urethane prepolymer had 14.7% isocyanate groups. The amount of polyethylene oxide in the polyol was 15%.

Reference Example 3 (Synthesis of Prepolymer C)
In a 1-liter flask, 450 g of MDI (M-5S manufactured by BASFINOAC Polyurethane Co., Ltd.) was added to and reacted with 300 g of DP-2000 and 100 g of Hyprox TG-3009 to obtain a urethane prepolymer. This urethane prepolymer had 14.7% isocyanate groups.

Moreover, the following were used about the catalyst and the viscosity reducing agent.
Catalyst A: Dimorpholinodiethyl ether Catalyst B: Catalyst A / DP-2000 = 1/9 (weight ratio) obtained by cutting catalyst A with polyoxypropylene diol (Hyprox DP-2000) having an average molecular weight of 2000
Thickener: Lisinolate derivative with hydroxyl group acetylated (methyl esterified product / hereinafter referred to as RAD)

Examples 1 to 4 and Comparative Examples 1 and 3
Above, to give a prepolymer A, B, C 及 Beauty E, a thinning agent and catalyst are mixed in the formulations shown in Table 1 each caking agent. Their viscosity, curability, internal curability, low-temperature coating whitening property, compressive strength, water-resistant compressive strength, and storage stability were measured, and the results are shown in Table 1.

The curability was determined by measuring the touch drying time in accordance with JISK-6301 and curing it within 1 hour.

For internal curability, a resin was uniformly applied at ² kg / cm ² to a ballast having a size of 10 to 20 mm (diameter) in an environment of 25 ° C., and internal curing was confirmed.
A product cured within 2 hours was evaluated as ◯, a product cured within 3 hours as Δ, and a product cured as 4 hours or more as x.

The low-temperature curing whitening property of the coating film was determined visually according to JISK-6301 to determine whether it was whitened after curing the coating film in a 5 ° C environment. A cured product that was not whitened at all was judged as ◯, a slightly whitened product as Δ, and a whitened product as x.

The compressive strength was obtained by adding 8% urethane resin to crushed stone of 5 to 10 mm and curing at normal temperature for 7 days, and then measuring the normal compressive strength.

The water-resistant compressive strength was determined by measuring the compressive strength immediately after taking out the test specimen cured with the above contents for one week and taking it out. Those having a strength retention after the water resistance test of 50% or more were evaluated as ◯, and those having less than 50% were determined as ×.

The storage stability was determined as “◯” when the product was stored at 50 ° C. for 1 month and did not hinder the work.

Example 5
² Kg / m ² of Example 1 was sprayed on a road bed spread with 20 kg / m ² of crushed stone having an average particle size of 5 mm, and then the caking agent was cured. The road bed thus obtained exhibited a compressive strength of 7.0 MPa, and had good internal curability and low-temperature coating whitening properties.

Claims (3)

Terminal isocyanate group-containing urethane prepolymer (A) obtained by reacting a polyol having a polyethylene oxide chain in the molecule with an organic polyisocyanate compound, and an alkyl monocarboxylic acid-modified hydroxyl group-containing higher fatty acid ester (B) as a thickener Is a caking agent for crushed crushed stone having a viscosity at 25 ° C. of 500 mPa · s or less, wherein the amount of the polyethylene oxide chain is 10 to 20 % by weight in the polyol. Solidifying agent for crushed stone.


The caking agent for a roadbed crushed stone according to claim 1, wherein the alkyl monocarboxylic acid-modified hydroxyl group-containing higher fatty acid ester (B) is a compound represented by the following general formula (1).

(Wherein, X: an alkyl group having 1 to 6 carbon atoms, Y: an alkyl group having 1 to 6 carbon atoms, n: an integer of 3 to 7 and m: an integer of 4 to 10) A method for stabilizing a bed bed, comprising applying the caking agent for road bed crushed stone according to claim 1 or 2 onto the crushed stone of the road bed.