JPH0365575A - Composition for foamed insulating material - Google Patents

Abstract

PURPOSE:To obtain a composition for foamed insulation material which gives a homogeneous foamed product without heat under the atmospheric pressure having stabilized properties in foaming start time and curing time by using water glass cullet powder, filler, foaming agent and water. CONSTITUTION:The subject composition for foamed insulation material comprises water glass cullet powder, filler, foaming agent and water. The water glass cullet powder is prepared by melting with heat silica sand and alkali metal and glassifying them and an alkali metal silicate free from crystal water or hydration water. Moreover, it is preferred that the silicate has 1.5 to 4.5 SiO2/R2O (R is Na, K) molar ratio and has more than 95wt.% solid content (represented by SiO2+R2O). As for the water glass cullet powder, potassium silicate is preferred, because the dissolving speed of potassium silicate is much higher than that of sodium silicate.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a composition for a foamable heat insulating material, and more specifically, a foamed heat insulating material having uniform cells can be obtained without heating under normal pressure, and The present invention relates to a foam insulation composition having stable foaming start time and curing time.

<Conventional technology> In recent years, there has been a growing trend toward insulating and making fireproof buildings and industrial equipment from the viewpoint of energy conservation and disaster prevention, and inorganic insulation materials with high heat resistance are attracting particular attention. There is.

As such inorganic heat insulating materials, many technologies related to foamed heat insulating materials using water glass as the main raw material have already been disclosed. Method (b): There is a method of adding metal powder as a foaming agent and using foaming gas to obtain a foam. Among these methods, in the method (b) above, in which the foamed heat insulating material can be dyed under normal pressure, the water glass used has a solid content of 30 to 55% by weight, represented by the formula S i O + 820 (R is an alkali metal). In most cases, an alkali metal silicate solution having a concentration of 70 to 80% by weight or a hydrous alkali metal silicate powder having a concentration of 70 to 80% by weight is used.

(Japanese Unexamined Patent Publication No. 57-77064, Unexamined Japanese Patent Application No. 57-821
No. 60, JP-A-60-137878).

By the way, when constructing water glass-based foam insulation materials using various fillers in combination with methods such as pouring, troweling, and spraying Gf, (1) sufficient crosstalk and pot life can be obtained; The foaming start time and hardening end time must be constant with no variation for each product rond of raw material powder, (2) Preparation for construction can be done with a simple process of adding water to raw material powder without the need for troublesome measuring operations. Requests have been made for the following: For these demands, especially (2), the use of hydrous alkali metal silicate powder can be premixed with various fillers and blowing agents, and can be used more advantageously than water glass. However, if a premix of hydrated alkali metal silicon M salt and a metal foaming agent is used as a foaming agent and stored, the metal powder will be damaged by the 20 to 30% water contained in the silicon M salt. As a result, not only the above requirement (1) cannot be fully satisfied, but also there are drawbacks such as caking during transportation and storage.

<Problems to be Solved by the Invention> In response to the above-mentioned problems, the present inventors have conducted extensive research into improving foam insulation compositions that use conventional alkali metal silicate powder as the main ingredient. As a result, it was surprisingly possible to form anhydrous alkali metal silicate powder, so-called water glass cullet powder, into a uniform foam under normal pressure without heating, and it also showed excellent reproducibility of foam properties and ease of workability. Furthermore, they found that the long-term storage property was also compromised, and the present invention was completed.

〈Means for solving problems〉 That is, the present invention (8) Water glass current powder (B) Filler (C) Foaming agent CD) water This is a foamed heat insulating material composition that is characterized by the fact that it roars.

The water glass current powder in the present invention is industrially vitrified by heating and melting silica sand and an alkali metal, and is an anhydrous alkali metal silicate substantially free of crystal water or hydration water. Furthermore, 5102/R20 (
However, R is Na or K) molar ratio is 1.5 to 4.5
, SiO2+R20 (where R is Na or K) is preferably 95% by weight or more.

In the above-mentioned water glass cullet powder, potassium silicate glass is more preferable because it has a much higher dissolution rate than sodium silicate glass.

However, some of the metal powders used as blowing agents, which will be described later, generate a large amount of heat during reaction and melting, and at this time, they promote the dissolution of water glass cullet powder, so sodium silicate glass is recommended. There is no inconvenience.

Further, the finer the particle size of the current powder is, the more preferable it is in the present invention, but it is generally suitable to have a particle size of 60 mesh or less.

Examples of the filler used in the present invention include (1) lightweight aggregates such as pearlite, shirasu balloon, vermiculite, pumice, and anti-flinder stone; (2) granulated blast furnace slag having alkaline hydraulic properties and pozzolanic activity; Fly ash, amorphous calcium silicates such as slag discharged from various metal refining processes, (3) kaolin, talc, batonite, sericite,
Clay minerals such as sepiolite and attapulgite, (4) Silica powder, F! Mineral powders such as algae, feldspar powder, dolomite, and zeolite (metal oxides or hydroxides such as 51Fi dealuminated magnesium oxide, titanium oxide, zirconia, aluminum hydroxide, calcium hydroxide, and magnesium hydroxide) ) Metal carbonates, sulfates, borates such as calcium carbonate, magnesium carbonate, sodium carbonate, sodium borate, calcium borate, calcium sulfate, etc. (7) Metals such as calcium silicate, magnesium silicate, zirconium silicate, aluminosilicate, etc. Silicates (8) From organic or inorganic Ia fiber materials such as asbestos, rock wool, glass fibers, ceramic fibers, calcium silicate-based fibrous or acicular crystals, pulp fibers, nylon fibers, etc., and carbon fibers. One or more selected types can be used.

In addition, as a blowing agent, S iz AJ % AJ −
3i, 3i-Ee, etc., metal percarbonates such as sodium peroxycarbonate, sodium peroxyborate, calcium peroxide, perborate, peroxide, hydrogen peroxide, etc.; or Two or more types can be used.

The particle size of the filler and U-foaming agent mentioned above does not need to be particularly limited, but in most cases, fine particles of 0.1 to 5 square meters are preferred for light ffi aggregates and fibrous materials, and 100 mesh or less for others. The blending ratio of these fillers, blowing agents and water is as follows:
The desired properties of the foamed insulation material, such as bulk specific gravity, compressive strength, bending strength, etc., or workability during construction, such as pot life, foaming initiation time, curing time, etc., can be changed in various ways. Although there is no need to particularly limit the filler, it is preferable that the filler be used in an amount of 10 to 100 parts by weight per 10 parts by weight of the water glass cullet powder. The reasons are 10
Even if a filler is used in excess of 0 parts by weight, it is difficult to obtain a foam having uniform cells, and if it is less than 10 parts by weight, sufficient mechanical strength will not be exhibited.

Further, it is preferable to use 1 to 10 parts by weight of the blowing agent per 100 parts by weight of the water glass current powder and filler. The reason for this is that even if more than 10 parts by weight of the foaming agent is used, the foaming state will be non-uniform and it is not economical, and if it is less than 1 part by weight, a heat insulating material with the desired bulk specific gravity cannot be obtained.

Also, water is a mixture of water glass current powder and filler.
Preferably, 10 to 60 parts by weight of water is used per 100 parts by weight.

The reason for this is that even if more than 60 parts by weight of water is used, there is a marked tendency for solid-liquid separation, and if less than 10 parts by weight of water is used, sufficient kneading cannot be achieved.

<Function> In the present invention, (A>water glass current powder, (B)
The mixture of the filler and (C) foaming agent does not substantially contain water, so no chemical reaction occurs, but when (D) water is added to the mixture, it foams, but after the foaming ends, heat generation begins. Since the foam evaporates and dries and hardens, a lightweight foamed body is quickly formed.

Furthermore, (A> Water glass current powder has a moderately slow dissolution rate, so the reaction between the released alkali and the blowing agent proceeds gradually. Therefore, the bubbles in the foam are small and many are generated. As a result, a structurally strong foam is formed.

<Examples> The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 to 3 and Comparative Examples 1 to 2 Water glass current powder-1 (S + 02 65° 5W
tX, Na20 31.5vItX (manufactured by Nihon Kagaku Kogyo Co., Ltd.) 150g, water glass current powder-2
(SiQ269.8WtX, K20 28.5Wt
X (manufactured by Nippon Kagaku Kogyo Co., Ltd.) 387 (), FuFlyara 12280, talc 645g, pumice (0.5~1n
+n) 538(I) were weighed and thoroughly mixed in a dry method to obtain a raw material powder.

Collect 100g of the above raw material powder, add 5q of various metals as a foaming agent, and place it in a plastic bottle at room temperature for 1 and 7 days.
It was left for 28 days on the 15th. After leaving it to stand, 40 g of water was added thereto, followed by kneading, and the foaming start time and foaming completion time were measured. In addition, as a comparative example, water-containing powdered sodium silicate No. 1 ts i02 55wtX, N was used instead of water glass cullet powder-1 and water glass cullet powder-2 among the raw material powders.
a2025wt%, 2022wt% Nippon Chemical Industry (
Co., Ltd.) (Comparative Example 1) and hydrated powdered silicate soda No. 2 (S
i O2 55wt%, Na20 22wt%, H2
A sample of 02it% Nihon Kagaku Kogyo (a) V> (Comparative Example 2) was prepared and the same test was conducted.

Table 1 shows the metal powder used and the test results.

As is clear from Table 1, by using the water glass current powder, a foamed heat insulating composition with excellent long-term storage stability was obtained.

Examples 4 to 7 and Comparative Examples 3 to 4 Using the water glass current powder-1, water glass cullet powder-2, and hydrous powdered sodium silicate used in Examples 1 to 3 and Comparative Examples 1 to 2, various raw material combinations were made. A product was prepared at the blending ratio of Group 2, water was added to obtain a foamed cured product, and various physical properties were investigated.

(Foam hardening test) The materials other than water in Table 2 were collected in a total amount of 1k (l), mixed in a plastic bag, left at room temperature for 28 days with air excluded, and then listed in Table 2 for each material. of water, knead for 1 minute, and form a 20n thick mold in a 200x 20011 mold.
Table 3 shows the results of pouring at +n and leaving to stand at room temperature to foam and harden. In Examples 4 to 7, foaming occurred after several tens of minutes due to rapid heat generation during kneading, and after foaming, dehydration due to hydration and evaporation occurred and the foams hardened, but in Comparative Examples 3 to 4, water was Foaming began during addition and kneading, and continued foaming in the mold, but the foam did not harden when the foaming ended, causing gas to escape and denting.

Table 3 <Effects of the Invention> According to the foam insulation composition of the present invention, when various fillers are used in combination and construction is performed by methods such as pouring, troweling, and spraying, (1) Sufficient (2) Adding water to the raw powder without the need for troublesome measuring operations. Effects such as being able to prepare for construction with only a few simple tasks can be obtained.

(3) The composition of the present invention can be easily used for heat insulation and insulation construction of complex-shaped tanks, piping, etc., and has excellent adhesion to metal concrete and slate.
Spraying can be used to provide fireproof coatings on buildings that have traditionally been constructed with asbestos.

Furthermore, among the raw material components of the present invention, even if (A> water glass current, (B) filler, and (C) blowing agent) are brezixed, they do not substantially contain water and no chemical reaction occurs. Therefore, the premix has the advantage of excellent storage stability.

Further, by using the above composition for foamed heat insulating material, it is possible to obtain a foamed heat insulating material that has a good foaming state and can be used for nonflammable building structures, industrial equipment, etc.

Claims (1)

[Claims] (1) (A) Water glass cullet powder (B) Filler (C) Foaming agent (D) Water A foam insulation composition characterized by comprising