JPS6012982B2 - Heat-foamable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alkaline silicate inorganic foamable composition,
More specifically, the present invention relates to an improved heat-foamable composition in which a phosphate is present on the surface of modified or unmodified solid hydrated alkali silicate glass.

Recently, inorganic foams have been developed for use in various fields including building materials because they are nonflammable. On the other hand, it has been known for a long time that poppy or acid-alkaline aqueous solutions foam when heated with inkstone water.

In particular, recently we have focused on the foaming properties of this poppy, acid-alkali, and
A large number of proposals have been made for the development of lightweight inorganic materials based on acids and alkalis. Of these, the majority of methods involve foaming by adding a sodium silicate aqueous solution and, if necessary, fillers, hardening agents, etc. and heating and dehydrating, but this method not only requires complicated operations and processes, but also improves water resistance and It has not been commercially successful due to insufficient fire resistance. On the other hand, it has also been proposed to produce foams using hydrous poppy or acid-alkali glass as starting materials. (Refer to Special Publication No. 50-18086). This method differs from the method of heating dehydration of an aqueous alkali silicate solution;
It is a water-containing glass made by hydrating acid-alkali glass with a limited amount of water, and is said to be industrially more advantageous than the former and more likely to produce uniform cellular foaming. However, this foam also does not have essentially improved heat resistance and water resistance. The present inventors have completed the present invention as a result of extensive research in view of the above-mentioned problems with poppy and acid-alkaline inorganic foams.

Phosphate (however, alkali metal salt This is a heat-foaming composition characterized by being coated with (excluding)

The present invention will be explained in detail below.

First, in the present invention, the solid hydrated silicate alkali glass is representatively suitable of the hydrated glass that we have already developed and proposed. A lump of anhydrous alkali silicate glass (cullet) is produced by melting it in a furnace and rapidly cooling it.

It is obtained by hydrating the powder obtained by crushing this cullet in the presence of limited water. For example, Tokuseki Showa 51
The documents described in Tokusei No. 97612 and Tokkoku Sho 52-12218 are related to unmodified hydrated silicate alkali glass, and those described in Tokkoku Sho 52-12217 and Tokko Sho 52-105918 are related to unmodified hydrated silicate alkali glass. What is described relates to modified solid hydrated alkali silicate glasses, such as solid hydrated shelf alkali silicate glasses and solid hydrated phosphorus alkali glasses. The solid hydrated alkali silicate glass of the present invention can be applied not only to unmodified glass but also to modified hydrated glass, and in particular, solid hydrated alkali silicate glass is a suitable material because it improves water resistance by itself. That is, the solid water-containing poppy or acid-alkali glass that can be preferably applied is obtained by hydrating anhydrous poppy or acid-alkali glass in the presence of limited water or an aqueous solution, that is, water, and the molar ratio Si0
2/M20 (M represents Na or K) is 1.5 to 4,
In particular, it is an unmodified or modified solid hydrated silicate glass having a water content in the range of 2 to 4 and a water content in the range of 10 to 4% by weight, especially 15 to 3% by weight.

Therefore, for example, the thermoplastic glass shell 0 solid hydrated alkali silicate glass manufactured by the method described in Samurai Publication No. 50-119011 and Tokusei Publication No. 50-119012 and expressed in the specifications is also true. This invention is applicable because it is a composite glass that belongs to the above category in the invention. Another modification of the unmodified hydrated alkali silicate glass may be a modified hydrated alkali silicate glass in which hydrophilic properties or hydrophilic groups are hydrated with a synthetic resin solution or an aqueous emulsion thereof. Furthermore, another modified product may be a non-uniform modification in which a filler is added as a modifier when anhydrous alkali silicate glass is hydrated.

Many such fillers are already known, and auxiliary agents such as suitable inorganic or organic fillers and colorants can also be used. As described above, in the present invention, the modified solid hydrated alkali silicate glass is a solid water having heat-foaming property obtained by hydrating an aqueous solution or an additive together with hydration of an anhydrous alkali silicate glass having at least the above composition. It is Japanese alkali silicate glass.

The mode of this modification is modified depending on the purpose of use. In any case, solid watertight acid alkali glass is
The physical properties are significantly different from that of ordinary alkali silicate solids, which are solidified by adjusting the water content by dehydrating an aqueous aqueous silicate solution called water glass, and are extremely delicate and have a high apparent specific gravity. The fine powder is so hard that it looks no different from ordinary glass pulverized products.

Therefore, the foamed material in the present invention is a pulverized product of such modified or unmodified hydrated alkali silicate glass, which has been adjusted to an appropriate particle size by pulverization, and the particle size has a large size depending on the foamed state. influence, but is often in the range of 50 to 20,000 Buddhas, preferably 100
It is in the range of ~loo00mu skin. If it is outside this range, the foaming properties tend to be unfavorable to the extent that a foam with low surface strength, poor moldability, or a uniform foam cannot be produced. Next, as another foaming agent for the solid hydrated alkali silicate glass, a so-called pre-foamed silicate obtained by foaming the above-mentioned hydrated alkali silicate glass particles in advance may be used.

This pre-foamed silicate has a moisture content of 5 to 4% by weight.
It is particularly preferably in the range of 10 to 3% by weight, and is a hollow spherical body of modified or unmodified hydrous silicate glass that is heat foamable.

If the above-mentioned modification is a chemical modification of water-containing glass, this hollow sphere can be said to be a physical modification. This pre-foamed material has an average particle size of 0.1 or more, preferably 0.1 or more.
It is a hollow spherical body in the range of 5 to 10 legs and has an apparent specific gravity of about 1 or less, particularly preferably in the range of 0.1 to 0.9.

In the present invention, when the blowing agent is fine particles of hydrated alkali silicate glass, the coefficient of volumetric expansion upon heating is large, so depending on the mode of use, uneven foaming may occur, resulting in a lack of uniformity as a foamed molded product. may be lacking.

This phenomenon occurs as the distance traveled in the internal space during foaming increases, so it is not a problem for compact and simple shaped molded objects because it is possible to obtain a homogeneous cellular foam, but it is not suitable for the opposite case. . Therefore, in the present invention, the pre-foamed silicate, which is another blowing agent, can be filled and occupied in advance in the internal space to be foamed, so that the movement distance inside the space is small, and even if it has a complicated shape, it can be integrated after filling. Foam can be formed.

Next, phosphate, which is another raw material, is used to modify the alkali silicate by mildly reacting when the hydrated glass is heated and foamed, thereby improving water resistance, heat resistance, etc. Ru.

Examples include alkali metal phosphates such as calcium, magnesium, and barium; phosphates such as aluminum, iron, chromium, zinc, zirconium, and titanium, and phosphate rock. Alkali metal salts are not suitable because they reduce the Si02/M20 molar ratio. The blending ratio of this phosphate is in the range of 5 to 60 parts by weight, particularly preferably 10 to 4 parts by weight, based on the weight of the water-containing glass 10 described above. Outside this range, improvements in fire resistance and the like tend to be insufficient, or conversely, moldability, foamability, strength, etc. tend to deteriorate. The heat-foamed composition according to the present invention is composed of the above two materials, and the phosphate is coated on the particle surface of the crushed solid hydrated alkali silicate glass. For coating, use a small amount of water or an inorganic or organic adhesive. In the present invention, a heat-foamed composition coated on a pre-foamed body is particularly suitable. In other words, since it is a pre-foamed hollow spherical body, not only is there almost no inhibition of foaming, but when obtaining a desired molded product, it is possible to pre-occupy most of the internal space with this product, making it possible to form a large mold. It is extremely effective as a foaming agent when producing any molded object, such as a mold with a complex body or shape.
The heat foaming composition according to the present invention is heated to about 200 to 1000°C.
It foams in the range of 5 and has improved heat resistance.
Not only can it be used as a foamed filler in heating spaces around 0.00 to 900.00 Celsius, regardless of the shape of the space, but it can also be molded into a desired shape and used as an inorganic lightweight material.

Next, the present invention will be specifically explained with reference to Examples. Example 1 25% by weight of water was added to anhydrous sodium silicate glass powder with a Si02/Na20 molar ratio of 3.19, and the hydrated sodium silicate solid was hydrated by curing to obtain a pulverized powder.

This powder is preheated in a rotary kiln, and a pre-expanded silicate with a water content of 1% by weight, a Si02/Na20 molar ratio of 3.19, an apparent specific gravity of 0.250, and an average particle size of 38 is used as a raw material for a blowing agent. A foamable composition was prepared by coating a predetermined amount of various phosphates on parts by weight of the hollow spheres 10. Next, this composition was placed in an iron mold of 10 ratio x 5 ratio x 2 parts with an apparent specific gravity of 0.26 to 0.
．． Fill to 479' (the amount that fills the space)
The mixture was heated and foamed at 500° C. for 1 hour. When this foam was tested as a test piece and its properties were examined, the results shown in Table 1 were obtained. In Table 1, moldability and heat resistance were judged as follows.

Judgment is made by looking at the condition of the foam molded product taken out from the mold.

○: Slight shrinkage and brittleness.

△ marks are brittle or have slight shrinkage; however, the black part marked with △ indicates the degree of stiffness.

× mark: Very brittle or highly shrinkable.

Cut out a part of a heat -resistant foam and make a test piece (2 revenge x 5 federates x 2 revenge). .

○ mark: There is no substantial change in the condition of the foam before and after the heat resistance test, and in particular, no heat shrinkage occurs throughout.

△ mark: Slight change in state is observed, especially volumetric contraction is 20
% or less.

× mark: Condition change is significant, especially volumetric shrinkage exceeds 20%.

The black part represents the arm.

Table 1 Example 2 A predetermined amount of water or an aqueous solution is added to anhydrous alkali silicate glass powder, and the resulting hydrated alkali silicate glass solids are pulverized into A, B, C, D, and E, respectively. Prepare raw materials.

The surfaces of the various hydrated alkali silicate glass powders were coated with zirconium phosphate together with a small amount of aqueous sodium silicate solution to prepare foamable compositions. The blending ratio is 15 parts by weight of zirconium phosphate to 10 parts by weight of solid hydrated alkali silicate glass. This foamable composition was heated and foamed in the same manner as in Example 1, and the properties of the molded products were examined, as shown in Table 2. Table 2 A: Molar ratio S
i02/Na20; 3.10, moisture content 22.3 wt.
Particle size of 0.25-1.

B: molar ratio Si02/Na20; 3.10, water content 18
．． 5 weight*, particle size 0.25-1. C: molar ratio S
i02/Na20: 3.10, B203: 0.8% by weight, moisture content 23.5% by weight, particle size 0.25-1. D: molar ratio Si02/Na20; 3.0, P205;
1.0 weight, water content 21.5 weight purple, particle size 0.25~
One desk.

E: Bure foam of C, moisture content 18% by weight, apparent specific gravity;
0.256, his with an average particle size of 3.8.

Example 3 The foamable composition prepared in Example 2 E was poured into the gap of a double curved iron pipe with a length of 50 m, an inner diameter of 4 stems, and a gap of 66 so that the gap was filled to the brim. Filled.

Claims (1)

[Claims] 1. Phosphate ( however,
1. A heat-foamed composition characterized by being coated with an alkali metal salt (excluding alkali metal salts). 2 The ground material of unmodified hydrated alkali silicate glass has a molar ratio S
iO_2/M_2O (M represents Na or K) 2-4
and a heat-foamable composition according to claim 1, wherein the water content is in the range of 10 to 30% by weight. 3. The heat foaming composition according to claim 1, wherein the pulverized product of modified hydrated alkali silicate glass is a pulverized product of hydrated borosilicate alkali glass or hydrated phosphosilicate alkali glass. 4 Phosphate is Ca, Mg, Zr, Zn, Al or Fe
The heat-foamable composition according to claim 1, which is a phosphate salt selected from the following.