JPS63178004A - Manufacture of light-weight aerated concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing lightweight cellular concrete, and in particular to a method for producing lightweight cellular concrete. This invention relates to improvements in layer formation methods.

[Conventional technology]

Lightweight cellular concrete is manufactured by pouring slurry to be used as lightweight cellular concrete into a formwork, solidifying the slurry, removing it from the formwork, and curing it in an autoclave. Generally, a film layer is formed on the surface of lightweight cellular concrete for the purpose of preventing water from penetrating into the lightweight cellular concrete.

Conventionally, the following methods 1) and 2) are known as methods for forming a film layer on the surface of lightweight cellular concrete.

1) Paint a room temperature curing type paint, such as an epoxy resin paint, a urethane resin paint, or a room temperature drying type paint, such as a lacquer paint, an emulsion paint, etc., on the surface of the lightweight cellular concrete.

2) As described in Japanese Patent Application Laid-Open No. 53-127521, a thermoplastic film or thermoplastic resin is coated on a mold in advance, and then slurry is injected, and after the slurry solidifies, the solidified The slurry is cured in an autoclave.

[Problems to be Solved by the Invention] However, the problem in 1) is that because the paint is applied to the surface of lightweight cellular concrete that has many bubbles and holes, it is difficult for the paint film to be uniform, and the film is Because holes often form and it is difficult to form a complete continuous film,
It is difficult to obtain stable performance in terms of water permeability and adhesion.

On the other hand, in the method for producing lightweight cellular concrete panels in 2), the thermoplastic resin film, such as polyethylene or polypropylene, is melted and impregnated and adsorbed to form a waterproof film layer because it is cured at high temperature and high pressure. The problem is that it is inferior. Furthermore, thermoplastic resins melt and impregnate under high temperature and high pressure, but there is also the problem that it is difficult to form a continuous film.

The present invention relates to a method for producing lightweight cellular concrete, and in particular, aims to provide excellent surface appearance, significantly reduce water permeability, and improve adhesion when forming a film layer on the surface of lightweight cellular concrete.

[Means for solving problems]

Conventionally, the surface of lightweight aerated concrete, which has many air bubbles and holes, is coated with paint that cures at room temperature or dries at room temperature to make it waterproof. can. This results in partial unevenness in water permeability and adhesion. In order to reduce water permeability and stabilize adhesion, it is necessary to cover the surface of lightweight cellular concrete with a uniform film. To this end, the inventors have discovered that the problem can be solved by attaching a continuous thermosetting resin film to the solidified slurry that is to become lightweight cellular concrete, and have completed the present invention.

That is, the present invention involves coating the inside of a formwork with a thermosetting resin, injecting a slurry that will become lightweight cellular concrete, and after solidifying the slurry, taking out the solidified slurry together with the resin film from the formwork, and removing the slurry. This method of producing lightweight aerated concrete is characterized by curing the solidified slurry in an autoclave.

As the thermosetting resin used in the present invention, as a main ingredient,
For example, polyurethane resins, acrylic melamine resins, diallyl phthalate resins, epoxy resins, phenol resins, polyester resins, epoxy ester resins, etc. As curing agents for these, for example, alkylated melamine resins, isocyanate compounds, amine compounds, acid anhydrides, Polyamidized metals and the like are used, and examples include combinations thereof and water-soluble thermosetting resins made by making them water-soluble.

The above-mentioned thermosetting resin used in the present invention includes inorganic pigments such as titanium dioxide, carbon black, iron oxide, and yellow lead used in ordinary thermosetting paints; organic pigments such as cyanine blue and cyanine green; and aluminum. powder, metal powder such as copper powder; extender pigments such as barium sulfate, curcum, mica, etc.;
Additives such as a pigment dispersant, a leveling agent, an antisettling agent, an antifoaming agent, a solvent, etc. can be added to form a thermosetting paint.

Thermosetting resin or thermosetting paint is diluted with thinner to a coating viscosity (Ford cup #4 at room temperature for 5 to 30 seconds) and painted by spray painting, brush painting, flow painting, etc. to make iron or plastic. The formwork 1 shown in FIG. After being left at room temperature for 5 to 60 minutes to form the thermosetting resin film 2 shown in FIG. 1, cement, silica powder, water, additives,
Slurry 3 of FIG. 1 consisting of a foaming agent and the like is injected and left at room temperature for 20 to 60 minutes to solidify and mold. After demolding, it was placed in an autoclave at 160°C to 200°C for 4 hours.
After curing for ~16 hours, lightweight aerated concrete is produced. The thermosetting resin film becomes a connected film due to the heat in the autoclave, so that a uniform continuous film layer is formed on the surface of the lightweight cellular concrete.

Here, if the coating viscosity is less than 5 seconds, it is too thin to form a sufficient film, whereas if it exceeds 30 seconds, coating becomes extremely difficult. Furthermore, if the thickness of the cured film is less than 10 μm, sufficient waterproofing cannot be obtained and it becomes difficult to form an uneven pattern on the surface, while if it exceeds too μm, demolding becomes difficult. Furthermore, if the autoclave temperature and time are less than 160°C for 14 hours, it will not be possible to form a film and cure the concrete, whereas if it is at 200'C for more than 16 hours, the film will be destroyed, impairing water permeability and strengthening the concrete. This may lead to a decrease in

[Operation] A thermosetting resin is coated on the inside of the formwork 1 in advance to form a thermosetting resin film 2 having a three-dimensional bridging structure.

When the slurry 3 is injected, demolded, and cured under high temperature and high pressure, the film is thermally softened and digs into the foamed part. This phenomenon results in strong adhesion to lightweight aerated concrete. Conventionally used thermoplastic resins do not have a three-dimensional structure, so they melt too much into lightweight aerated concrete, resulting in uneven film thickness.However, the thermosetting resin used in the present invention has a three-dimensional structure. , it partially penetrates into the lightweight cellular concrete and forms a uniform continuous film on the surface, making it possible to obtain lightweight cellular concrete with significantly improved water permeability.

〔Example] Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Example 1: A thermosetting acrylic melamine resin paint (Belcoat klooO white:
(manufactured by Nippon Oil & Fats) with the specified thinner (Belcoat Nα100)
0 Thinner 8 (manufactured by NOF)
4 for 20 seconds (25° C.), spray-painted, and left at room temperature for 30 minutes, to form a thermosetting resin film 2 of 50 μm as shown in FIG. 1 on the mold. Next, slurry 3 shown in FIG. 1 having the following composition was poured into the solution, and the solution was left at room temperature for 30 minutes.

After the slurry solidifies, it is demolded and heated to a high temperature (180″c).
After curing under high pressure (IO atmosphere) for 8 hours, lightweight cellular concrete was prepared and performance tests were conducted. Table of performance test results
Shown in 1.

Portland cement 50 parts by weight silica powder
50!11 parts alumina cement
5 parts by weight Water 50 parts by weight Synthetic polymer polyvalent metal salt 1 part by weight (Bafoam EPM-1: manufactured by Kao Soap Q) Example 2; Thermosetting polyurethane resin paint (urethane No. 10)
00 White Nippon Oil & Fats ■) with a Ford Cup #4 using the specified thinner (urethane thinner: Nippon Oil & Fats ■).
Dilute to 0 seconds (25°C), spray paint to form a thermosetting resin film with a dry film thickness of 50 μm as in Example 1, and inject the same slurry as in Example 1 to create lightweight cellular concrete. A performance test was conducted. The performance test results are shown in Table-1.

Example 3; Thermosetting water-based acrylic melamine resin paint (Aqua No.
71. OO white: Nippon Oil & Fats ■) was diluted with water in a Ford cup #4 for 20 seconds (25'C) in the same manner as in Example 1, and lightweight aerated concrete was prepared in the same manner as in Example].
A performance test was conducted. The performance test results are shown in Table-1.

Example 4: Using a thermosetting epoxy resin paint (Ebico Nα1500 White, manufactured by NOF ■), it was applied for 20 seconds (2
5'C), lightweight cellular concrete was prepared in the same manner as in Example 1, and a performance test was conducted.

The performance test results are shown in Table-1.

Comparative Example 1: Slurry 3 shown in FIG. 1 similar to that in Example 1 was poured onto mold 1 made of polypropylene shown in FIG. 1, and left at room temperature for 30 minutes. After the slurry solidifies, it is demolded and heated to a high temperature (180°C).
, and cured for 8 hours under high pressure (10 atm). Next, a room-temperature curing epoxy resin paint (Ebico Sealer manufactured by Nippon Yushi Corporation) was applied to the surface using a specified thinner (Ebico Thinner manufactured by Nippon Yushi Corporation Ltd.) for 20 seconds (25 seconds) using a Ford cup #4.
A lightweight cellular concrete having a cured film rg of 50 μm was prepared by diluting it to a temperature of 20° C. and then pour-coating it, leaving it to dry at 20° C. for 24 hours, and conducting a performance test. The performance test results are shown in Table-1.

Comparative Example 2: Thermoplastic acrylic resin paint (Acryte Nα50) was applied to the formwork.
0 White: 2 with Ford Cup #4 using Nippon Oil & Fats ■)
Adjust to 0 seconds (25°C), spray paint, 20°C
This was left for 24 hours to form a 50 μm thermoplastic resin film. Next, the same slurry as in Example 1 was injected,
It was left at room temperature for 30 minutes. After solidifying Slurry 3, it was demolded and cured at high temperature (180°C) and high pressure (10 atmospheres) for 8 hours to produce lightweight cellular concrete, and a performance test was conducted.

The performance test results are shown in Table-1.

Comparative Example 3: Polyethylene film of thermoplastic resin (thickness 0
．． 3 mm), and the same slurry as in Example 1 was injected thereon to produce lightweight cellular concrete in the same manner as in Example 1, and a performance test was conducted.

The performance test results are shown in Table-1.

The performance test results of the Examples and Comparative Examples are shown in Table 1 below.

Table-1 Performance test results The criteria for determining each performance in the table are as follows.

(1) Appearance: Lightweight aerated concrete surface condition O...
A state in which a uniform, glossy film layer is formed.

Δ: A state in which a non-uniform glossy film layer is formed.

×: A state in which the film is destroyed due to non-uniformity.

(2) Autoclave resistance A resin film is attached to the Nislurry coagulated body and cured in an autoclave at 180° C. and 10 atm for 8 hours, and damage to the resin film is evaluated.

O...No damage at all.

Δ...Slightly damaged surface condition.

×: The film has decomposed and disappeared.

(3) Water permeability: A glass tube with a diameter of 10 m5 and a length of 300 M is erected on the membrane, and the surrounding area is covered with a sealant (waterproof sealing: manufactured by Cemedine ■). Water is poured into it to a height of 2501 from the surface of the film, and the amount of decrease in water level after 24 hours is displayed on the screen.

(4) Adhesion: Pinch the edge of the film and peel it off. Evaluate the state of adhesion of lightweight cellular concrete to the film.

○: Lightweight aerated concrete adheres to the entire surface of the film.

Δ: Lightweight aerated concrete adheres to part of the film.

×: Lightweight aerated concrete does not adhere to the film.

As is clear from the above results, the performance shown in Examples 1 to 4 is excellent in appearance, has excellent adhesion to lightweight cellular concrete, and can withstand autoclave conditions during manufacturing. . Water permeability, which is the main objective, is also reduced compared to the comparative example.

Compared to this, Comparative Example 1 is inferior in appearance, water permeability, and adhesion, and Comparative Examples 2 and 3 are inferior in appearance, autoclave resistance, and
Poor water permeability and adhesion.

〔Effect of the invention〕

By coating the thermosetting resin of the present invention on a mold, pouring the slurry onto it, and after solidifying, removing the thermosetting resin film from the mold, and curing the solidified slurry in an autoclave. . 0. A lightweight cellular concrete with excellent surface appearance is obtained; and 2. A lightweight cellular concrete that is impermeable to water and has a thermosetting resin film with good adhesion.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view when slurry to become the lightweight cellular concrete of the present invention is injected. 1... Formwork, 2... Thermosetting resin film, 3... Slurry 〇

Claims (1)

[Claims] (1) Coat the inside of the formwork with thermosetting resin, inject lightweight aerated concrete slurry, and after the slurry solidifies, take out the solidified slurry together with the thermosetting resin film from the formwork. A method for producing lightweight aerated concrete characterized by curing solidified slurry in an autoclave.