JPS6071563A - Curing agent for water glass - 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 The present invention relates to a solution of sodium silicate, calistopol silicate, a so-called hardening agent for water glass.

Water glass is inexpensive and has zero properties (it has traditionally been widely used as a binding agent in sealants and coating materials). However, if water glass is left to air dry and harden,
Since the alkali silicate itself, which is a component of water glass, exhibits water-tsubaki properties, it becomes a cured product with very poor water resistance. For this reason, sodium silicofluoride, aluminum phosphate,
Various hardening agents such as condensed aluminum phosphate and acetate ester have been used to improve water resistance, but the reality is that none of them are satisfactory.

For example, silicic acid soda, which is generally well known as a hardening agent for water glass, is a hazardous substance and is subject to some restrictions in its handling.When using it, it is difficult to control its pot life, and the cured product is not water resistant. It has the disadvantage of being inferior.

In addition, when manufacturing condensed aluminum phosphate, which is said to have relatively good physical properties such as water resistance,
In order to carry out the condensation process, a special permanent manufacturing method is required,
It has the disadvantage that it is quite complicated and it is difficult to obtain an inexpensive one. In any case, each curing agent has its advantages and disadvantages, and the reality is that none of them are necessarily satisfactory.

In order to solve the above problem, the inventors of the present invention conducted an investigation and found that aluminum phosphate glass exhibits good physical properties as a hardening agent for water glass. “Furthermore, this aluminum phosphate glass powder is treated with a solution of a substance that reacts with phosphate ions to form an insoluble or poorly soluble salt, such as an aqueous calcium hydroxide solution, and the resulting product is used as a hardening agent for water glass. In particular, it has been found that not only the water resistance but also the workability, that is, the pot life, of the cured product can be easily adjusted.

'J-Fluminium glass is essentially made of alumina (
A420a) and anhydride/dicarbonate (P2O5) are considered to have continuous -0-kt-0-P-0- bonds.

As the At20° source for such aluminum phosphate glass, alumina or aluminum hydroxide, etc., and P20! + For cooling, phosphoric acid and ammonium salts of phosphoric acid can be considered, but others t203 and P2O5
At203, PllO, and A/g20, which are the chemical compounds of
It can be produced by appropriately mixing and adjusting 3°3P'gOs, etc., and melting it at high temperature and then rapidly cooling it.

The vitrification range of the AjiO, -P2O, system is generally At2.03, 3PaOs (AtzOs 19.3
At203, 3 p2oIi and k120s -P2O
The eutectic point composition of 1 is slightly richer in AjiO3 t2033
It has been found that glass can be obtained with a composition of up to 0'2it*%p2o, 701%p2o.It is possible that glass can be obtained with other compositions, but when producing glass,
l! When there is a large amount of Os, a considerably high temperature is required to melt it.
Furthermore, as the amount of P2O5 increases, the amount of evaporation of P2O5 increases, making it more difficult to produce aluminum phosphate glass. Therefore, the curing agent of the present invention usually uses phosphorus within the above composition range. Acid aluminum glass is used.

When this aluminum phosphate glass is used as a hardening agent for water glass, it is ground to an appropriate particle size. Generally, the finer the particle size, the better, but for practical purposes, 88 μm or less is suitable. It was discovered that the cured product prepared in this manner was used as a hardening agent for water glass and exhibited good water resistance, and this is the invention of Section 1.

However, in the first invention, when the entire aluminum ruphosphate I-cis powder is used as a curing agent, there is almost no problem with water resistance, but if the particle size is fine, the pot life is about 30%.
Since it is shorter than 1 minute, it is practical. It is considered that there is often a need to further extend the pot life.゛As a result of various studies, we found that by reacting aluminum phosphate glass powder with phosphate ions and a solution of a substance that forms an insoluble or poorly soluble salt, such as a calcium hydroxide solution, °- It was discovered that the pot life can be easily reduced, and this is the second invention.

Substances that form this insoluble or M-soluble salt include, in addition to calcium hydroxide, chlorium hydroxide, trontronium hydroxide, etc.; however, inexpensive calcium hydroxide is usually sufficient. The reason for the longer pot life is probably the reaction between P2O and Oa ions near the surface of the aluminum phosphate glass powder particles, and the formation of a MU-like substance on the particle surface that prevents the reaction with water glass. It is thought that this may be for a reason.

In any case, by performing such treatment, it is possible to greatly adjust the pot life to several hours or more without affecting the water resistance etc. of the cured product. A hardening agent is obtained.

The water glass used in the present invention is not particularly limited, and any commonly commercially available water glass can be used. Further, the use of the curing agent according to the present invention is 20 to 100 parts by weight per 100 parts by weight of water glass, and in the case of No. 3 water glass, it is usually 30 to 50 parts by weight, resulting in a cured product with good water resistance. is obtained.

Furthermore, when the curing agent of the present invention is mixed with water glass,
The resulting cured product exhibits self-curing properties and has good water resistance after curing without being particularly subjected to high-temperature treatment and can be used for fireworks.

Next, the curing agent of the present invention will be explained in more detail with reference to Examples.

Example a) Curing agent backing method (1) Riff ti 7 Luminium (AtPO4)
100? VCxJ Si! Uniammonium J phosphate 148 r”.

I mixed it, put it in the gamma tank, covered it with an alumina lid, heated it to 1450℃ for about an hour, held it for 30 minutes, and then put it in water. ifi quenching 1~A4203
Approximately 24 layers of lid tIIP205 approximately 761i (obtained 7% aluminum phosphate glass 7c5) Next, the obtained glass was dried and crushed to less than 88, (Z tn) to form an aluminum phosphate glass hardening agent (sample 1). .

(100 parts of aluminum phosphate glass S powder obtained by the method of 21(1), 0.25 part of calcium hydroxide, 100 parts of water)
A hardening agent for water glass (sample 2) was obtained by heating the entire beaker containing the shrine for about 1 hour until the water evaporated by using a heater.

(3) Aluminum phosphate obtained by method (1)
100 parts of lath powder, 0.5 parts of calcium hydroxide, 10 parts of water
0 rrtt: fr: In addition to the following (2), process I2 on the same machine
hardening agent for surface-treated water glass (trial (4) (1)
A mixture of 100 parts of aluminum phosphate glass powder obtained by the method described above, 0.75 parts of calcium hydroxide, and 200 uJ of water was added to a beaker, and the mixture was heat-treated for about 2 hours until the water evaporated to perform surface treatment. A hardening agent for water glass (sample 4) was obtained.

(5) The same method as in (4) was carried out except that the total amount of calcium hydroxide added was 1.0 part to obtain a bottom-treated curing agent (Sample 5).

b) Pot life The following studies were conducted regarding the pot life when water glass and each curing agent obtained by the Mtr M manufacturing method were mixed.

Commercially available No. 3 water glass (NazO9.4% electricity, 5i02
A mixture of 40 parts of each of the above-mentioned curing agents to 100 parts (29.4%) was mixed in a mud cellar for about 3 minutes, and then placed in a 37 x 50 L container made of polystyrene. When the container was turned upside down from time to time at intervals of 5 to 20 minutes, the pot life was defined as the time it took for fluidity to disappear. The results are shown in Table 1. Note that this test was conducted indoors at approximately 21°C.

Stripes 1 front (Note) *Soda silicofluoride was tested for comparison.

The mixing ratio of sodium silicofluoride and Na20 min in the water glass is (2Na20 + NagSiF6→
Assuming that it hardens according to the reaction formula of 6N'ali' + SiO A piece with punctures of micrometer or less was used. .

As is clear from these results, the curing agent of the present invention
It has the characteristic that the pot life can be easily adjusted, which is difficult to do with conventional curing agents.

In addition, the cured product using the sample according to the present invention was 2
After 4 hours, everything was cured.1. Even when they were subjected to a 5-hour boiling test in submerged water, it was confirmed that there was almost no surface erosion and good water resistance, even when compared with those using sodium fluorosilicide f as a hardening agent.

C) Strength of hardened water glass mortar Samples A, B, and 0 used the above-mentioned sample 4 as a hardening agent, and the sample was made by drying water glass mortar with the composition shown in Table 2 using sodium fluorosilicide. and put it in the formwork 2X2X8c
Specimen preparation of yn 1-strong hair 611 was determined.

In addition, when the mortar k is 1llI=l%, the water in the mortar is 25'! ii: , i, Add tap water to make up the missing amount [adjusted with ~] Strength test of these water gases - results are shown in Table 3.
It was ii'+ri.

As is clear from the results in Table 3, the hardening agent of the present invention is as good in strength development as the one using sodium fluorosilicide, and also has good water resistance. A problem-free cured product can be obtained.

In the above example, Sample 5, which has a long pot life as a curing agent, was used as a curing agent.
However, even when other curing agents (samples 1 to 4) shown in the 'iAZm example were used, the strength development after 3 days showed that there was no cracking. . As for the pot life when water glass mortar is used as in Maniwa Honjo Example, if the water glass mortar has sufficient fluidity to be harvested, the pot life shown in Example 2 will be the same. ■
A value close to 1 was obtained.

Patent applicant: Chichibu Cement Co., Ltd. Same agent, Osamu Clothes Department -

Claims (1)

[Claims] (1) Hardening agent for water glass consisting of aluminum phosphate glass powder (21 Aluminum phosphate glass powder is brought into contact with a solution of a substance that reacts with phosphate ions to form an insoluble or sparingly soluble salt) , a hardening agent for water glass made from aluminum phosphate glass which has been treated with a oxidizer to reduce the reactivity between aluminum phosphate glass powder and water glass.