JPS5830260B2 - Inorganic insulation composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel inorganic heat insulating material composition, and more particularly to an inorganic foam heat insulating material composition having uniform cells and having excellent mechanical strength and chemical resistance.

Various inorganic heat insulating materials have been proposed so far.

For example, those mainly composed of alkali metal silicate aqueous solutions,
In both cases, heating operation (usually 200 to 900°C) is required, and the alkali metals are inherently inferior in water resistance and moisture resistance. Contact with moisture easily causes the alkali metals to be leached out, and It has drawbacks such as a significant decrease in physical strength, and has almost no practical use as a heat insulating material.

Furthermore, lightweight inorganic materials such as lightweight concrete and lightweight mortar using Portland cement as a binding material are known, but their specific gravity is high (around 1.0) and lacks practical use as a heat insulating material.

Furthermore, lightweight aerated concrete cured in an autoclave is complicated to operate, and it is difficult to obtain a lightweight foam; even the lightest concrete has a bulk specific gravity of 0.5 or more.

The present invention provides a useful inorganic heat insulating material composition that can overcome the performance disadvantages of these conventional inorganic lightweight heat insulating materials, such as light weight, mechanical strength, and chemical resistance.

That is, the present invention essentially provides (4) a water-soluble alkali silicate, (B) alumina cement or a mixture of alumina cement and Portland cement, or a mixture of alumina cement and an alkaline earth metal compound, (C) a metal-based A blowing agent, and (consisting of a synthetic resin emulsion)
Furthermore, the present invention relates to an inorganic heat insulating material composition characterized in that a foaming stabilizer (as an additional component) is mixed with the above-mentioned components (A) to (2).

The inorganic heat insulating material composition of the present invention easily becomes a foamed heat insulating material at normal temperature and pressure by simply mixing the above components (A) to 0 or the above components (A) to 2) into a paste form. It has a short curing time, can be molded into complex shapes, and has a uniform specific gravity regardless of weather conditions.

The heat insulating material after foam hardening has an extremely low bulk specific gravity of about 0.1g, /- to 3g1crA, which is impossible with lightweight aerated concrete, which is conventionally known to have a high mechanical strength. Not only can it be adjusted and its thermal conductivity can be lowered to the level of lightweight cellular concrete, but it also has uniform bubbles and its cell structure is extremely strong.

Therefore, it has poor insulation and weather resistance, and also exhibits excellent water resistance, moisture resistance, alkali resistance, and mechanical strength.

One of the most notable effects is improved water resistance, moisture resistance, and alkali resistance.

That is, without mixing the synthetic resin emulsion, which conventionally has no component, the free alkali in the foamed insulation material gradually separates onto the surface or inside of the foamed material due to solid phase movement or movement with the aid of water, resulting in a white powdery phenomenon. It was not possible to prevent this phenomenon, and this phenomenon did not impair the aesthetic appearance of the insulation material, but greatly reduced the mechanical strength itself. However, the inventors of the present invention have conducted extensive research in order to prevent this phenomenon. As a result, they discovered that mixing a synthetic resin emulsion is very effective in preventing the migration of free alkali in foam insulation materials.

According to the inventors' estimation, free alkali is apparently fixed at the stage when the synthetic resin emulsion is uniformly dispersed within the foamed insulation material to form a film, and this becomes even stronger after drying and curing. It is thought that.

In any case, the reason is not clear, but since the alkali resistance has also been greatly improved, it seems that the synthetic resin emulsion film itself has undergone deterioration that exceeds its original alkali resistance. .

In the present invention, it is essential to use a water-soluble alkali silicate as component (A), and examples of constituents thereof include water-soluble silicates of alkali metals such as lithium, sodium, and potassium; As long as the component (4) is water-soluble, its composition and molar ratio are not limited;
The molar ratio of the alkali and the alkali is preferably 15 to 4.0.

The above-mentioned component (A) can be advantageously used alone or in combination of two or more in the form of a powder or an aqueous solution, but the solid content concentration is usually 20 to 60%. It is preferable to use it in the form of a water-soluble axillary solution.

The alumina cement as the component (B) is a hydraulic cement whose main components are Cao and Al2O3, and in the present invention, commercially available products with various compositions can be used as the component (B).

Its composition is generally Ca030-59 and Al2033
Fe203 is in the range of 9 to 53, and other impurities include Fe203.
1-16%, S+023-9%.

The above-mentioned alumina cements can be used alone or in combination of two or more, and they are preferably used in the form of a powder having a particle size of about 100 μm or less.

Further, in the present invention, the alumina cement M may be used in combination with a predetermined amount of Portland cement and/or an alkaline earth metal compound.

Portland cement is an ordinary cement whose main hydraulic components are silicic acid and calcium, and commercially available products are classified in the industry as ordinary Portland cement, early strength Portland cement, ultra early strength Portland cement, moderate heat Portland cement, etc. Although there are some differences in composition,
Any of these portland cements can be used in the present invention.

As alkaline earth metal compounds, calcium and magnesium oxides, hydroxides or sulfates can be used in the same way as in Portland cement.

One or more of these portland cements or alkaline earth metal compounds are effective in shortening the hardening time when used together with the above alumina cement in the form of powder with particles of approximately 100μ or less, but If a large amount is blended, curing tends to be too rapid, making it difficult to achieve good foaming.

Therefore, it is preferable to use each in an amount of 50 parts by weight or more based on the solid content relative to 100 parts by weight of the alumina cement.

In the present invention, various metal elements, metal alloys, and intermetallic compounds can be used as the metallic foaming agent as component (C).

Metal elements in the periodic table IB, IIA, II
B, IA, BIB, ■A, ■B1VA, VB
.

In addition, in the present invention, metalloid elements such as B and Si can also be used in the same manner as the above-mentioned metal elements.

In the present invention, alloys or intermetallic compounds (chemical combinations between metals or between metals and non-metals) of the above metals can also be used in the same manner as the above metals.

Typical examples of the alloy or intermetallic compound are:
AI-8i, AI-T i, Al-Mn, AI
-Cu-8i.

AI-CLL, Zn-8, Zn-8n, 5n-Fe
, Cu-8n.

Cu-8i, kCu-Pb, Cu-Ni, F
e-Ni, Fe-Mn.

Fe-Cr, Fe-8i, Mn-P, 8i
-Ni,,Co-8b.

Examples include Mn-Ag.

It is usually preferable to use one or more of the above components (C) in the form of a fine powder, particularly preferably in a particle size of 150 μm or less.

The synthetic resin emulsion used as a component in the present invention is not particularly limited in type, and includes synthetic rubber latex in a broad sense, including vinyl acetate, acrylic ester, methacrylic ester, ethylene, Styrene, vinyl chloride, VeoVa, vinyl propionate,
Aqueous dispersions (emulsions) of homopolymers or copolymers of two or more of butadiene, chloroprene, isoprene, vinylidene chloride, diallyl phthalate, diallyl maleate, dibutyl maleate, epoxy, urethane, etc. can be used, as required. The dispersibility can be improved by adding a small amount of anionic, /ionic or amphoteric surfactant to the synthetic resin emulsion in advance.

In addition, the foaming stabilizers used as ingredients in the present invention include silica gel, zeolite, artificial zeolite, carbon black, activated carbon, dalc (talcum), and mica (mica).
Inorganic substances selected from the following and organic substances conventionally known as cement-based foaming agents such as animal protein and dimethyl silicon derivatives can be used.

These components) have the effect of uniformly dispersing one component in the system, stabilizing the foaming reaction, and are effective in producing fine, uniform cells.

When the component (@) is an inorganic substance, it is usually desirable to use it in the form of a powder with a particle size of 200 μm or less.

The blending ratio of the above components (A) to (a) is determined by the type of substance used as each component, especially when (A) JR, is used in the form of an aqueous solution, its concentration and the bulk specific gravity of the desired product.
Although it varies depending on the strength and conditions during molding to obtain the desired product, the slippage is good if used in a normal method.

That is, based on the solid content of component (A), the solid content outside the range B is about 100 to 700 parts by weight, preferably about 140 to 500 parts by weight, and the C component is 0.5 to 35 parts by weight. It may be about 100%.

In addition, (D) 51i is preferably used at an agricultural yield of 5% or more, with a solid content of about 2 to 30 parts by weight.

The present invention consists of the above (4) to ((n) component only, but in order to further improve the mechanical strength)) components are mixed, and (■)
If the component is an inorganic substance, the solid content is 5 to 5.
Approximately 50 parts by weight, and if it is an organic substance, the solid content is 0.
．． The amount may be about 1 to 3 parts by weight.

In general, if component (4) is present in excess, the air bubbles and bulk specific gravity will not be stable, resulting in a non-uniform foaming state and an insulating product with poor water resistance. During adjustment, the viscosity of the paste tends to become too high, resulting in poor workability.

Also, if the amount of component (C) is too small, foaming will be insufficient and the bulk specific gravity of the product will be heavy ((more than 1.0 degree)), and if it is too large, the air bubbles in the product will be large and over-foamed, resulting in the desired strength. It becomes difficult to obtain products with

If the amount of component (D) is too small, the water resistance and moisture resistance will not be improved much, and if it is too large, the fire resistance etc. will decrease and gelation may occur.

If the amount of the component (B) is too small, the foaming will be slightly lacking in uniformity, and if it is too large, it will be difficult to adjust the paste.

The thus prepared heat insulating material composition of the present invention may further contain a lightweight aggregate powder, such as foamed silica, perlite, vermiculite, and shirasu balloon, which is usually fired at 1000° C. or higher, as required. The bulk specific gravity of the product can be made smaller.

Furthermore, it is possible to add various known fillers such as gypsum, fused quartz, calcined listoparite, silica powder, fly ash, alumina powder, and glass fiber for the purpose of weight increase, reinforcement, etc.; It is necessary to be careful about the type and amount of addition so as not to interfere with the reaction form of the essential components (A) to ().

Such a composition usually has air bubbles in the range of 0.5 to 10 m, has low specific gravity, high strength, and has high water absorption.
An inorganic foam insulation material with excellent water resistance, moisture resistance, chemical resistance, heat insulation, flame resistance, etc. can be obtained.

Examples will be given below to explain the present invention in more detail.

Example 1 An inorganic heat insulating material composition having the following composition was prepared.

(4) 100 parts by weight of sodium silicate aqueous solution (Si02./Na2O molar ratio 2° O1 concentration 20%) (B) 100 parts by weight of alumina cement (A120/CaO molar ratio ■, 57, manufactured by Denki Kagaku Kogyo Co., Ltd.) ) Metallic silicon 5 parts by weight (DJ Acrylic-
Styrene resin emulsion (emulsified with anionic activator,
10 parts by weight (concentration: 40%) The above mixture was thoroughly stirred and mixed and foamed in a plastic container at room temperature and pressure to obtain a foamed heat insulating material molded product.

The physical properties of this material are specific gravity 0.35 and compressive strength 8 kgl.
It was a rug.

When this molded product was left to stand for 72 hours in a high-humidity atmosphere filled with carbon dioxide gas at a temperature of 50° C. and a humidity of 80 RH% or more, no powdering was observed on the surface or inside of the foam.

Further, when this molded product was immersed in water maintained at 20° C. for 24 hours and then exposed to air, no powdering on the surface or inside of the foam was observed even after a week had passed.

From the above, it can be seen that the material has excellent moisture resistance and water resistance.

Example 2 In addition to the composition of Example 1, a particle size of 5 to 5 was added as a component.
A foamed heat insulating molded product was obtained by mixing 50 μm of activated carbon and using the same method as in Example 1.

The physical properties of this material are specific gravity 0.32 and compressive strength 7kg/f.
It was fl.

Further, when moisture resistance and water resistance were tested in the same manner as in Example 1, no abnormality was found.

Example 3 Based on the method of Example 1, the compositions shown in Table 1 were adjusted to obtain a foamed insulation material.

Table 2 shows the results of testing these foam insulation materials by adding new test items.

Comparative Example In Example 1, when a foamed heat insulating material was prepared without mixing the synthetic resin emulsion (O component), the physical properties were as shown in Table 2.

Note that tests other than those for moisture resistance and water resistance in Table 2 were conducted in the following manner.

・Bulk specific gravity: According to JIS A1161 ・Compressive strength:
According to JIS A1161 - Alkali resistance: Saturated Ca
Observe the presence or absence of powdering after immersion in (OH)2 solution for 2 days. Compressive strength after water resistance: JIS A11 after water resistance test
According to 61.

Claims (1)

[Claims] 1 substantially δ, (4) a water-soluble alkali silicate, (B) an alumina cement or a mixture of alumina cement and portland cement, or a mixture of alumina cement and an alkaline earth metal compound; ( An inorganic heat insulating material composition comprising C) a metal foaming agent tag and O) a synthetic resin emulsion. 2 Substantially, (4) Water-soluble alkali silicate, (C) Alumina cement or a mixture of alumina cement and Portland cement, or a mixture of alumina cement and an alkaline earth metal compound, (C) Metallic blowing agent IJ. (D) An inorganic heat insulating material composition comprising a synthetic resin emulsion and a foaming stabilizer.