JPH05280011A - Method of fixing sand in pavement process - Google Patents

Abstract

PURPOSE:To fix sand in such a condition that the cushioning ability inherent to the sand is maintained, by spraying a material obtained by water-soluble prepolymer having a specific composition over laid sand or joint sand so as to form a resin layer. CONSTITUTION:A compound having a polyoxyalkylen chain having more than two hydroxyl groups at its terminal end having a molecular weight of 1,000 to 2,0000 is allowed to react with a polyisocianate compound having a molecular weight equal to or greater than that of the hydroxyl group so as to obtain a water-soluble prepolymer. The prepolymer is then dissolved uniformly in water at a concentration of 3.0 to 7.0% so as to obtain a solution which is sprayed over laid sand or joint sand in order to obtain a resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing sand in pavement work.

[0002]

2. Description of the Related Art In laying interlocking blocks, colored flat plates, or stones on a pavement surface in various types of pavement work, such laying materials should not be destroyed by external force after laying. The lower layer ground of the floor covering is covered with sand or the joints of the floor covering are covered with joint sand to form a vertical or horizontal cushioning material. However, sand itself is not tacky. Therefore, if sand is simply sprinkled on the lower ground or joints, the sand may be washed away or moved due to factors such as rainfall, vibration or wind, and the cushioning property may be lost, and other inconvenience may occur. This problem will be described below with a specific example. (Specific Example 1) When the pavement surface has a gradient of 10 degrees or more, if there is rainfall with a strength of 2500 mm / hr or more, the flow sand causes the bed sand and the joint sand to be washed away, and the cushioning property is lost. (Specific Example 2) When the pavement surface is a road with a large amount of traffic or a container yard through which large vehicles pass, the cushioning property is lost due to the movement of the set sand and joint sand. (Specific Example 3) When the pavement surface faces the shopping street, the joint sand is blown into the store by the wind and the displayed products in the store are contaminated. (Specific Example 4) When the paved surface is poolside, the joint water may be washed out by the cleaning water, which may hinder walking with bare feet, and the joint sand may flow into the pool.

In order to deal with these problems, conventionally, unavoidably, cement is mixed into sand to fix the sand. As for the spread sand, there is a method in which the sand is sandwiched between two upper and lower woven fabrics and fixed. However, the former method has a problem in that the cushioning property which is the original reason for using sand is lost due to the mixing of cement, and when this method is used for joint sand, the surface of the flooring material is soiled. There is a risk of spoiling the aesthetics. In addition, the latter method has a problem that it cannot be used as joint sand.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention has an object to provide a method for fixing sand in paving work for fixing the spread sand or the joint sand in a state where the cushioning property thereof is maintained. To do.

[0005]

In order to achieve the above object, the immobilization method of the present invention comprises a polyoxyalkylene chain having two or more hydroxyl groups at one end and having a molecular weight of 1,000 to 20,000. The water-soluble prepolymer obtained by reacting the compound having with a polyisocyanate compound having the same or more moles as the number of hydroxyl groups is added to water in an amount of 3.0 to
What was made to melt | dissolve uniformly at the density | concentration of 7.0% is sprayed on the spread sand or the joint sand, and it is characterized by forming a resin-ized layer.

[0006]

According to the fixing method of the present invention, a sprinkling material mainly composed of the water-soluble prepolymer having the above-mentioned composition is sprinkled on the spread sand or the joint sand, and the sand is fixed in a cushioned state. The spraying material is produced by making a water-soluble prepolymer composed of an isocyanate compound into a rubber by a hydration polymerization reaction.The water-soluble prepolymer is uniformly dissolved in water to give a spraying material, and the spraying material is applied to sand. By spraying, a rubber-like resinized film is formed on the surface of the sand by the hydration polymerization reaction. Further, the decrease in viscosity due to the water solubility is used to penetrate the sand to solidify the sand particles forming a layer from the surface of the sand to a certain depth to form a rubber-like resin layer. The water-soluble prepolymer strongly adheres to the sand particles by the hydration polymerization reaction. Therefore, a great resistance is exerted against the loss or movement of sand. In addition, the formed resin layer accompanies foaming during the hydration polymerization reaction of the water-soluble prepolymer, and since the foaming is closed cells and has a heat insulating property, frost columns and frost heave are effectively prevented. The water-soluble prepolymer is dissolved in any water to form a solution having a uniform concentration. The hydration polymerization reaction is usually prepared in about 5 to 30 minutes. At this time, all excess water is included in the solidified body. The usable concentration of the water-soluble prepolymer in the present invention is 3.0 to 7.0% in terms of the solid content of the prepolymer, and any strength can be obtained by adjusting this concentration. Concentration is 2.0%
In the following cases, it does not solidify, but within the range of 3.0 to 7.0%, a rubber-like resinized film and resinized layer are formed. The resinized film and the resinized layer absorb rainwater and swell. If the concentration exceeds 7.0%, the viscosity becomes too high, and it becomes difficult to uniformly spray.

The water-soluble prepolymer used in the practice of the present invention has a compound having two or more hydroxyl groups at the end and a polyalkylene chain having a molecular weight of 1,000 to 20,000 (hereinafter referred to as a polyalkylene oxide compound). And a polyisocyanate compound having the same number of moles or more as the number of vidroxyl groups, at 30 to 120 ° C. for 30 minutes to 7
It is obtained by introducing a isocyanate group at both ends of a polyalkylene oxide compound by reacting for a day with a catalyst such as diptyltin dilaurate or triethylenediamine, if necessary. The water-soluble prepolymer is liquid or paste at room temperature. The time from the addition of the water-soluble prepolymer to water to the solidification can be accelerated by adding a basic substance such as an amine compound and delayed by adding an acidic substance such as an acid chloride compound. is there.

The polyalkylene oxide compound used in the present invention is a compound having two or more hydroxyl groups at the terminal, which is obtained by adding a long chain of alkylene oxide to a compound having active hydrogen. Compounds having active hydrogen include ethylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, sucrose, polyols such as methylglucoside, amines such as ethylenediamine, diethylenetriamine and methylamine, tall oil. , Rosin acid, adipic acid, carponic acid and esters such as castor oil, and compounds having two or more hydroxyl groups obtained by the reaction of aldehyde with other compounds (eg, olefin, aromatic hydrocarbon, etc.) . A compound obtained by mainly addition-reacting ethylene oxide, and secondarily another alkylene oxide, or a mixture thereof with these compounds having active hydrogen shows excellent water solubility. The prepolymer obtained by the reaction with the polyisocyanate compound has a water solubility and a viscosity of the aqueous solution, and when the prepolymer aqueous solution is sprayed on the soil, the polyalkylene oxide has such a length as not to impair the permeability to the destination layer area. A range having a chain is preferable, or it is necessary to take a polyalkylene oxide chain and a molecular weight range of a range capable of imparting similar penetrability by adding a dispersant, a solubilizing agent and the like. Therefore, as for the molecular weight of the polyol, in the case of polyethylene glycol, the molecular weight is 100
0 to 20,000, preferably 1,000 to 4,000
The range is appropriate. The same applies to other polyalkylene oxide compounds. In the present invention, the reaction ratio in the synthesis of the prepolymer is 2 to 8 mol (weight) of the polyisocyanate compound with respect to 1 mol (weight) of the polyalkylene oxide compound. Selected by several groups. The concentration is determined in such a range that the molecular weight of the prepolymer obtained as a result of the reaction does not significantly increase the viscosity of the aqueous solution and does not hinder the water solubility. The polyisocyanate compound used in the present invention is a compound having two or more isocyanate groups having an organic compound as a base, and examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate and xylylene diisocyanate. , A diisocyanate compound such as hexamethylene diisocyanate, and a triisocyanate compound such as triphenylmethane triisocyanate. The alkylene oxides used in the present invention include ethylene oxide, propylene oxide, butylene oxide, styrene oxide and epichlorhydrin.

[0009]

EXAMPLES First, a synthesis example of a water-soluble prepolymer will be described. (Synthesis Example 1) 200 parts of a copolymer diol having an average molecular weight of 3,000 and a weight ratio of ethylene oxide / propylene oxide of 85/15 and tolylene diisocyanate 5
2.2 parts were reacted at 90 ° C. for 3 hours to obtain a water-soluble prepolymer. This water-soluble prepolymer is a stable compound which is liquid at room temperature and has little change with time in a sealed state. (Synthesis example 2) 694 parts of polyoxyethylene glycol having an average molecular weight of 1,000 and tolylene diisocyanate 30
6 parts were reacted at 90 ° C. for 2 hours to obtain a water-soluble prepolymer. (Synthesis Example 3) 780 parts of polyoxyethylene glycol having an average molecular weight of 2,000 and xylene diisocyanate 22
0 part was reacted at 90 ° C. for 2 hours and 30 minutes to obtain a water-soluble prepolymer. (Synthesis Example 4) A water-soluble prepolymer was obtained by reacting 748 parts of polyoxyethylene glycol having an average molecular weight of 2,000 with 252 parts of hexamethylene diisocyanate at 70 ° C for 5 hours.

(Synthesis Example 5) 740 parts of a copolymer polyol having an average molecular weight of 2,000 obtained by addition reaction of glycerin with thylene oxide and propylene oxide at a ratio of 35 mol: 6 mol and tolylene diisocyanate 2
A water-soluble prepolymer was obtained by reacting 60 parts with 90 ° C. for 2 hours. (Synthesis Example 6) 822 parts of polyoxyethylene glycol having an average molecular weight of 4,000 and tolylene diisocyanate 17
A water-soluble prepolymer was obtained by reacting 8 parts with 90 ° C. for 3 hours. (Synthesis Example 7) 843 parts of a copolymer polyol having an average molecular weight of 4,000 obtained by addition reaction of ethylene oxide and propylene oxide with ethylene glycol at a ratio of 72 mol: 14 mol and xylene diisocyanate 1
57 parts was reacted at 70 ° C. for 3 hours to obtain an aqueous prepolymer. (Synthesis Example 8) 889 parts of a copolymer polyol having an average molecular weight of 8,000 obtained by addition-reacting glycerin with ethylene oxide and propylene oxidide at a ratio of 126 mol: 41 mol and hexamethylene diisocyanate 1
A water-soluble prepolymer was obtained by reacting 11 parts with 70 ° C. for 5 hours.

(Synthesis Example 9) 240 mol of ethylene oxide and propylene oxide in ethylene glycol:
Average molecular weight 1 obtained by addition reaction at a ratio of 77 mol
925 parts of 5,000 copolymer polyols and 75 parts of tolylene diisocyanate were reacted at 90 ° C. for 4 hours to obtain an aqueous prepolymer. (Synthesis Example 10) 657 parts of a copolymer polyol having an average molecular weight of 4,000 obtained by addition-reacting sorbitol with ethylene oxide and propylene oxide at a ratio of 77 mol: 10 mol, and xylene diisocyanate 343.
This was reacted with 90 parts at 90 ° C. for 3 hours to obtain an aqueous prepolymer. (Synthesis Example 11) 70 parts of 754 parts of a copolymer polyol having an average molecular weight of 6,000 and 246 parts of hexamethylene diisocyanate obtained by addition-reacting sorbitol with ethylene oxide and propylene oxide at a ratio of 110 mol: 20 mol. An aqueous prepolymer was obtained by reacting at 6 ° C for 6 hours. (Synthesis Example 12) 800 parts of a castor oil ethylene oxide adduct having an average molecular weight of 4,000 and 200 parts of tolylene diisocyanate were reacted at 90 ° C. for 4 hours to obtain a water-soluble prepolymer.

Next, examples will be described according to the above specific examples. (Correspondence to specific example 1) The thickness of the sand is 3 on the slope with a gradient of 20 degrees.
It was laid by cm and rolled, and the spray material obtained by mixing and stirring 5 parts of the water-soluble prepolymer of Synthesis Example 1 and 95 parts of water was uniformly sprayed. The amount of spray per unit area was 2.0 l / m ² . Next, an interlocking block was laid, further filled with joint sand, and 5 parts of the water-soluble prepolymer and 95 parts of water were mixed and stirred, and the spray material was uniformly sprayed at a rate of 1.5 l / m ² . After leaving for 1 hour after spraying, when uniform water spray was continuously applied to the slope, no runoff or migration of sand was observed. The thickness of the layer formed by the polymerization reaction of the water-soluble prepolymer and water was about 5 mm. Note that the top surface of the block should be cleaned before the spreading material hardens (the same applies to the following examples). (Correspondence to specific example 2) Assuming a container yard where a road with a large amount of traffic or a large vehicle passes, the sand is 3 cm thick.
Was laid and rolled, and 5 parts of the water-soluble prepolymer and 95 parts of water were mixed and stirred, and the spray material was uniformly sprayed at a rate of 2.0 l / m ² . Next, an interlocking block was laid, and further, joint sand was filled, and a spray material obtained by mixing and stirring 5 parts of the water-soluble prepolymer and 95 parts of water was 1.0 to 1.5 l / m ^2.
Was evenly sprayed. After curing for 1 hour after spraying, no movement of paved sand or joint sand was observed. The thickness of the layer formed by the polymerization reaction of the water-soluble prepolymer and water is 5 to 7 m.
It was m.

(Correspondence to Specific Example 3) An interlocking block was laid on the pavement surface, filled with joint sand, and 5 parts of the water-soluble prepolymer and 95 parts of water were mixed and agitated.
When sprayed uniformly at a rate of 5 l / m ² , no sand was blown up by the wind. (Correspondence to Specific Example 4) An interlocking block was laid on the pool side, filled with joint sand, and mixed with 5 parts of the water-soluble prepolymer and 95 parts of water, and the mixture was stirred at 1.0 l /
It was sprayed uniformly at a rate of m ² . After leaving for 1 hour after spraying, when uniform watering was continuously given to the pavement surface, no runoff or migration of sand was observed.

[0014]

The present invention has the following effects. That is,
A method of spraying a spraying material mainly composed of a water-soluble prepolymer having a predetermined composition on a bed sand or a joint sand to fix the sand in a state of having a cushioning property, and the bed sand or the joint sand,
It is possible to fix them while maintaining the cushioning property.

Claims (1)

[Claims] 1. A reaction between a compound having two or more hydroxyl groups at one end and a polyoxyalkylene chain having a molecular weight of 1,000 to 20,000 and a polyisocyanate compound having the same or more moles as the number of hydroxyl groups. It is characterized in that the water-soluble prepolymer thus obtained is uniformly dissolved in water at a concentration of 3.0 to 7.0%, and is sprayed on the spread sand or joint sand to form a resinized layer. How to fix sand in pavement work.