JPH091041A - Spray process - Google Patents

Abstract

PURPOSE: To form a spray film having good waterproof, moistureproof, and airtightness by mixing a mixture containing an emulsion of a specified concentration and powders as main components with a liquid thickener in the air and forming a slow-curing type rubber-asphalt-cement solid layer on a treatment surface. CONSTITUTION: A mixture 1 containing a rubber-asphalt emulsion of 50wt.% or more solid content and cement powders as main components and a liquid thickener 8 which cures the cement powders are prepared. The nozzle 7 of an airless spray 3 for the mixture 1 is placed in the middle, while the nozzles 14, 15 of an airless spray 10 for the thickener 8 are arranged at both ends. The pressurized thickener 8 is first sprayed from the nozzles 14, 15 forming two expanses. When the pressurized mixture 1 is ejected from the nozzle 7, the mist of the mixture 1 is enclosed by the mist of the thickener 8, and they hit a treatment surface while being contacted and mixed with each other to form a rubber-asphalt-cement solid layer 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spraying method, and more particularly, to a cement-based powder when a mixture containing a rubber-asphalt emulsion and a cement-based powder as main components is sprayed onto a surface to be adhered. By simultaneously spraying a liquid thickener that can cure the above, and mixing both in the air, in the space until reaching the surface to be adhered, an instant and strong thickening effect is obtained, and The present invention relates to a spray spraying method capable of forming a slowly hardening type rubber-asphalt-cement solid layer on the surface and forming a thick coating film excellent in waterproofness, moisture resistance and airtightness.

[0002]

2. Description of the Related Art In recent years, as a method for spraying a rubber-asphalt emulsion, a high-concentration rubber-asphalt emulsion and a gelling agent aqueous solution such as an aqueous solution of a polyvalent metal salt capable of breaking and gelling the emulsion. , A thick film made of a rubber-asphalt solid layer having a strong adhesive force by spraying simultaneously from different nozzles and causing both liquids to collide with each other before and / or when they reach the adherend surface to cause an instant gelation reaction. There is a method of forming
8-41107).

In this method, since the rubber-asphalt emulsion has already instantaneously gelled before and / or when it reaches the adhered surface, the continuity of the coating film after spraying shows that the adhered surface is smooth. It is easily affected by the degree. For example, in the case of an underground outer wall made of cast-in-place concrete constructed in the fields of construction and civil engineering, irregularities such as misalignment of formwork, pinholes and junkers are inevitable in the finish of the surface layer. When such a rough surface is sprayed by the above method, a coating is formed faithfully to the shape of the adhered surface. As a result, the film thickness varies at the edge portions of the irregularities, and the shrinkage force when the film is dried may concentrate on the thin film portion, leading to the occurrence of cracks.

On the other hand, as a rubber-asphalt emulsion waterproofing agent spraying method which is not affected by the smoothness of the adhered surface, a cement-based powder is mixed with the rubber-asphalt emulsion and, if necessary, a methylcellulose thickener is added. Add and disperse the added substance with air 2
A method of spraying using a fluid nozzle to form a rubber-asphalt-cement solid layer on the adhered surface is known. However, this method is not suitable for vertical spraying due to the limitation of the discharge capacity of the pressure-feeding pump, which is a problem when the viscosity of the sprayed material is significantly increased, and the problem of viscosity behavior due to the change in environmental temperature when a methylcellulose-based thickener is added. It is very difficult to apply a thickness required for waterproof performance to the surface or the ceiling surface without dropping the material in one spraying operation.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It forms a slowly hardening type rubber-asphalt-cement solid layer on the surface to be adhered, which is waterproof and moisture-proof. An object of the present invention is to provide a spraying method capable of forming a thick coating film having excellent airtightness.

[0006]

The present invention has a solid content concentration of 5
A mixture containing 0 wt% or more of rubber-asphalt emulsion and cement-based powder as main components and a liquid thickener that hardens the cement-based powder are mixed in the air using a spray nozzle, and the mixture is applied to the adherend surface. Characteristically, a slow curing type rubber-asphalt-cement solid layer is formed on the adhered surface by continuously contacting the mixture with the liquid thickener in the space until reaching and the adhered surface. It is to provide a spray spraying method.

The rubber-asphalt emulsion, which is the base material of the present invention, may be any of anionic, cationic and nonionic ones. However, cement-based powder is added and mixed, and pressurized by a plunger pump or the like to cause airlessness. It must have sufficient emulsion stability to be sprayed. The solid content of the rubber-asphalt emulsion is an important item related to the thickening performance of the present invention, and is in the range of 50% by weight or more, preferably 50-80% by weight, more preferably 60-80% by weight. If it is less than 50% by weight, the gelling action at the time of mixing the thickener is small, and a predetermined thickening effect cannot be obtained. On the other hand, if it exceeds 80% by weight, it may be difficult to add the cement-based powder, and the curing time may be delayed, so that it may not be practically applicable.

Examples of the rubber in the rubber-asphalt emulsion include natural rubber, styrene-butadiene copolymer rubber, butyl rubber, polybutadiene rubber, chloroprene rubber, acrylic rubber, ethylene-vinyl acetate copolymer and the like. Copolymer rubber,
Having a carboxyl-modified styrene-butadiene copolymer as a main component is excellent as a rubber-asphalt-cement solid layer in terms of performance and economy.

As the asphalt in the rubber-asphalt emulsion, natural asphalt, straight asphalt, blown asphalt and the like can be mentioned, and any of them can be used. The rubber content in the rubber-asphalt emulsion is not particularly limited, but is preferably 5 to 50% by weight, more preferably 10 to 30% by weight based on the total solid content of the rubber-asphalt.
It is. If it is less than 5% by weight, the effect of modifying the asphalt is small and it is difficult to maintain the performance of the rubber-asphalt coating over a wide temperature range. On the other hand, if it exceeds 50% by weight, the flexibility and tackiness of the rubber-asphalt coating will be impaired, and the original waterproof performance of the rubber-asphalt will be lost.

The cement-based powder used in the present invention is preferably a cement which produces a larger amount of ettringite product at the end of the hydraulic reaction. Specific examples thereof include ordinary Portland cement and early strength Portland cement. , Super early strength Portland cement, medium-sized Portland cement, jet cement, blast furnace cement, silica cement, fly ash cement and the like. The average surface area of this cement-based powder is usually 3,0
It is about 00 to 6,000 cm ² / g.

The amount of the cement-based powder added is preferably 2 based on 100 parts by weight of the total solid content of rubber and asphalt.
The amount is 0 to 100 parts by weight, more preferably 20 to 50 parts by weight. If the amount of the asphalt-based powder added is less than 20 parts by weight, the coagulation of the rubber-asphalt emulsion will be delayed, free water will not be easily captured, and it will take a long time to cure. On the other hand, if it exceeds 100 parts by weight, the risk of cracking of the formed film and the deterioration of performance such as reduction of elongation are caused.

As a method for preparing the mixture containing the above rubber-asphalt emulsion and cement-based powder as main components, molten asphalt is made into an aqueous emulsion using an emulsifier, and rubber latex or emulsion is added to and mixed with the mixture to obtain rubber. -A method of preparing an asphalt emulsion and mixing cement-based powder before use, melting rubber in asphalt, homogenizing by mixing, then making an aqueous emulsion with an emulsifier to prepare a rubber-asphalt emulsion, and cementing before use. Examples thereof include a method of mixing powders of a system, a method of making a molten asphalt into an aqueous emulsion with a rubber latex or an emulsion and an emulsifier to prepare a rubber-asphalt emulsion, and mixing a cement powder before use.

In addition to the rubber-asphalt emulsion and cement-based powder, various surfactants, antioxidants, plasticizers, fillers and the like may be added to the above mixture as required.

Next, the liquid thickener gives the rubber-asphalt emulsion a moderately gelled state, thereby imparting a viscosity that enables sufficient thicknessing, and a hardening action of the cement-based powder. It has a cement quick setting effect of accelerating and coagulating the rubber-asphalt emulsion with the minimum required amount of cement powder added. Although the viscosity of the liquid thickener itself does not directly affect the performance of the present invention, it is preferably a low viscosity because spraying is performed. As the liquid thickener, water glass, colloidal silica, aqueous solution of silicate such as lithium silicate, in organic system, isocyanate, aqueous solution of polyacrylic acid, aqueous solution of tannic acid, other ammonium chloride, ammonium zirconium carbonate, etc. At least one selected from the following gelling agents is preferable, and silicate aqueous solution is preferable, and colloidal silica is particularly preferable. This colloidal silica is a colloidal solution in which ultrafine particles of silicic acid anhydride are dispersed in water using water as a dispersion medium.

A filler may be added to the above liquid thickener depending on its properties. The solid content concentration or the active ingredient content of the liquid thickener is usually about 5 to 50% by weight, preferably about 15 to 40% by weight.

Further, it is desirable that the amount of the liquid thickener used is as small as possible in order to maintain the flexibility and water resistance of the coating film formed by spraying. , But it depends on each type and concentration, but the volume ratio is preferably 1/15 to 1
/ 5, more preferably 1/10 to 1/7. If the ratio of the liquid thickener is too small, the gelling action at the time of mixing the thickener is small and the desired thickening effect cannot be obtained. On the other hand, if the amount is too large, there is a risk of cracking of the formed coating film and deterioration of performance such as deterioration of coating film elongation.

The spraying machine used in the present invention is preferably an airless type. In a conventional spraying machine, a so-called air spray method in which sprayed material is sprayed by compressed air is widely used. This type has a simple structure of spraying machine and is excellent in spraying workability, but on the other hand, the scattering of the spraying material is great, and therefore the mixture (rubber-asphalt emulsion + cement) and liquid thickener are effectively used. There is a drawback that an imperfect surface is observed for thickening and solidifying the mixture by contact mixing with and. That is, since the scattering is significant, it is a serious problem particularly in the above mixture containing a black rubber-asphalt emulsion, and the significant scattering is that the liquid thickener is not intensively injected into a certain limited range. Contact with is not efficient enough.

On the other hand, the airless spraying machine applies a high pressure to the spraying material with a suitable pump and sprays it from the pores. Since air is not used, a limited pattern can be formed very efficiently. Moreover, since it collides with the adherend surface at a high speed, the adherence is good, and a dense spray material layer can be formed. at the same time,
There are many advantages such as very little scattering and therefore less loss of spray material. The airless type may be a plunger type pump that uses air or a hydraulic motor, or an electric diaphragm type pump.

The present invention will be described below with reference to the drawings. First, a mixture 1 in which a rubber-asphalt emulsion and a cement-based powder are mixed and a liquid thickener 8 are prepared. Further, two units, an airless sprayer for mixture 3 and an airless sprayer for liquid thickener 10, are prepared. Mixture (rubber-
The asphalt emulsion + cement) and the liquid thickener are sucked up from the pipes 2 and 9 of the respective pumps, passed through the pumps of the respective spray machines, and are pressurized to the pressure hoses 4 and 11, and the spray guns 6 and 1.
Reach 3. When the cocks 5 and 12 at the hand of the spray gun are opened, they are jetted from the jet port at the tip. The nozzles, 15, and 7 are attached to the ejection port, which have pores having a unique shape that determines the ejection amount and the spray pattern. The nozzle 7 for the mixture is located in the center, and the nozzles 14 and 15 for the liquid thickener are provided at both ends thereof.
Are spaced from the nozzle 7 within 10 cm,
Each of them is arranged slightly inclined toward the center.

First, the cock 12 is opened and the pressurized liquid thickener is sprayed from the nozzles 14 and 15 in the form of mist droplets onto the adherend surface in two spreads. Subsequently, the cock 5 is opened and the fog droplets of the pressurized mixture are ejected from the nozzle 7 and collide with the adhering surface 16 while being contact-mixed in the space so as to be surrounded by the fog droplets of the liquid thickener. The mixture is thickened to form a rubber-asphalt-cement solid layer 17. In this way, the mixture (rubber-asphalt emulsion + cement) is thickened by a small amount of liquid thickener in a very short time (at the same time as it is attached to the space and the adherend), and a solid layer is formed on the adherend. It The thickened coating formed on the adhered surface is the cement-based powder mixed in the rubber-asphalt emulsion, which absorbs water in the emulsion to promote emulsion destruction, and at the same time, the cement thickening action by the liquid thickener. This accelerates the curing, and the synergistic action of the natural dry curing stably forms a thick coating composed of the rubber-asphalt-cement solid layer.

Depending on the nature of the adhered surface, if a suitable primer is applied before spraying, the adhesion between the adhered surface and the rubber-asphalt-cement solid layer can be improved. . Examples of the primer include anionic or cationic rubber-asphalt emulsion, rubber latex, resin emulsion and the like.

As described above, according to the present invention, the slowly hardening type rubber-asphalt emulsion waterproofing material mixed with cement powder is thickened in one spraying step without dripping on the vertical surface and the ceiling surface. Therefore, it is possible to significantly reduce the labor required for waterproofing, moisture proofing and airtight construction. INDUSTRIAL APPLICABILITY The present invention is a waterproof layer forming on a roof, a waterproof layer forming on an outer wall surface, a moisture-proofing for a refrigerator, a refrigerator, a heat-retaining room, an air-proofing layer, a fumigation warehouse, an air-proofing layer for silos, an underground structure, a waterproof layer for a bridge, etc. It is used for molding, waterproofing of chemical storage tanks, heat insulating layer molding, etc., and can be constructed quickly and efficiently without polluting the surrounding area.

[0023]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by these. In addition,
In the examples, parts and% are based on weight unless otherwise specified. Further, various measurement items in the examples are values obtained as follows. 50 g of the sample sprayed on the curable release paper in a sealed state was put in a 100 ml polyethylene container and tightly stoppered, and the cured state was observed by touching with fingers at 20 ° C. Adhesion to concrete sidewalk boards Commercially available concrete sidewalk boards (300 x 300 x 35 m
m) was sprayed with each spray material in a thickness of 4 mm, and the adhesive strength after curing for 72 hours in a wet state was examined.

Example 1 170 parts of a rubber-asphalt emulsion having a solid content of 70% [manufactured by Japan Latex Processing Co., Ltd., JSR Spray GP-A] was added to a cement-based powder [manufactured by Japan Latex Processing Co., Ltd.]. , JSR Spray GP-
B] was added in an amount of 60 parts and uniformly stirred with a stirrer to prepare a modified rubber-asphalt emulsion mixture. A large airless coating machine [Asahi Sunac Co., Ltd.,
Air spray using Super Bear NP2554],
At the same time, colloidal silica [Asahi Denka Co., Ltd., AT-3
0] of 15% diluted aqueous solution was sprayed using a small airless coater [Light Bear AP1636 manufactured by Asahi Sunac Co., Ltd.], and a 15% diluted aqueous solution of colloidal silica was added to 80 parts of the modified rubber-asphalt emulsion mixture. While being mixed in the air at a ratio of 10 parts, it was sprayed on a vertical adherend surface to form a film.

Comparative Example 1 In Example 1, 0.2 part of a methylcellulose-based thickener [SM-25, manufactured by Shin-Etsu Chemical Co., Ltd.] was added to 100 parts of the modified rubber-asphalt emulsion mixture, and the mixture was stirred. After uniformly stirring and increasing the viscosity, a commercially available cup gun for painting was used to spray on a vertical adhered surface by an air spray method in the same manner as in Example 1 to form a film.

Comparative Example 2 A rubber-asphalt emulsion having a solid content of 82% [JSR Spray manufactured by Japan Latex Processing Co., Ltd.] was aired using a large airless coating machine [Super Bear NP2554 manufactured by Asahi Sunac Co., Ltd.]. At the same time, 5% calcium chloride aqueous solution was airless sprayed using a small airless coating machine [Light Bear AP1636 manufactured by Asahi Sunac Co., Ltd.], and 10 parts of calcium chloride 5% aqueous solution was added to 70 parts of rubber-asphalt emulsion. While mixing in the air in a ratio, spray on the vertical adherend surface,
A coating was formed.

The sprayed coatings of Example 1 and Comparative Examples 1 and 2 were made as thick as possible, and the value of the thickness that could be retained without sagging was measured. Separately, the curing time in a sealed state and the commercially available concrete sidewalk board (300 × 300 × 35) after curing for 72 hours in a wet state
mm) was measured. Table 1 shows the results.

[0028]

[Table 1]

* 1) Cohesive failure of spraying material * 2) Cohesive failure of spraying material 30%, interfacial peeling between spraying material and concrete 70% Comparative Examples 1 and 2 are based on the conventional construction technique,
In comparison with Example 1, Comparative Example 1 does not have a sufficient maximum film thickness,
Comparative Example 2 is inferior in curability and adhesive strength during wet curing.

Example 2 In Example 1, except that the total solid content of the rubber-asphalt emulsion was adjusted to 73% in advance and the same cement powder was added in an amount of 40 parts.
Spraying was carried out in the same manner as in Example 1, and the maximum workable film thickness on the vertically adhered surface at the time of mixed spraying with colloidal silica was measured. In addition, the curing time in a sealed state was separately measured.

Comparative Example 3 In Example 2, the colloidal silica was not mixed and only the modified rubber-asphalt emulsion mixture was airless sprayed to measure the maximum film thickness that can be applied to the vertically adhered surface. In addition, the curing time in a sealed state was separately measured.

Comparative Example 4 In Example 1, a sample in which the total solid content of the rubber-asphalt emulsion was adjusted to 45% in advance was used, and the same cement-based powder was added in an amount of 60 parts as it was, and the mixture was sprayed with colloidal silica. The maximum film thickness that can be applied to the vertical adhered surface was measured. In addition, the curing time in a sealed state was separately measured.

The results of Example 2 and Comparative Examples 3 to 4 are shown in Table 2. In Example 2, even if the amount of cement-based powder was reduced,
Due to the gradual gelation and hardening promoting action of the colloidal silica, it hardens within a practical range of time and at the same time secures a maximum film thickness of 10 mm <. However, when the colloidal silica is not mixed in Comparative Example 3, the thickening effect cannot be obtained,
The curability in the hermetically sealed state is also significantly delayed, so it is not practical. In Comparative Example 4, the total solid content of the rubber-asphalt emulsion was outside the range specified in the present invention, and even if the amount of the cement-based powder added was the same as in Example 1, the thickening effect was obtained. Absent.

[0034]

[Table 2]

[0035]

According to the spraying method of the present invention, a slowly hardening type rubber-asphalt-cement solid layer is formed on the adhered surface to form a thick coating film excellent in waterproofness, moisture resistance and airtightness. It is possible to

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a construction method of the present invention.

[Explanation of symbols]

 1 Rubber-asphalt emulsion 2,9 Suction pipe 3,10 Airless sprayer 4,11 Pressure hose 5,12 Cock 6,13 Injection port (spray gun) 7,14,15 Nozzle 8 Liquid thickener 16 Wall surface 17 Rubber -Asphalt-Cement solid layer

Claims (2)

[Claims] 1. A mixture containing a rubber-asphalt emulsion having a solid content concentration of 50% by weight or more and a cement-based powder as a main component, and a liquid thickener for curing the cement-based powder in the air using a spray nozzle. In the space until reaching the adherend surface and the liquid thickener are continuously brought into contact with the adherend surface, a slowly curable rubber-asphalt-cement solid is adhered to the adherend surface. Spray spraying method characterized by forming a layer. 2. The spraying method according to claim 1, wherein the liquid thickener is an aqueous silicate solution.