JPS58120548A - Fireproof glass plate - Google Patents

Abstract

PURPOSE:To provide a fireproof glass plate having excellent light transmittability and fireproof function without causing clouding for a long period of time by providing an intermediate layer of sodium silicate wherein the molar ratio of SiO2/Na2O is in a specific range between plural glass plates. CONSTITUTION:Preferably 7-20wt% glycerol is added to sodium silicate of 3.7- 3.9 molar ratio of SiO2/Na2O, and the mixture is coated on the top surface of a glass plate and is dried, whereby a transparent water glass film of 20-35wt% moisture content is formed. Thereafter, plural sheets of glass plates are sandwiched in such a way that the resultant water glass film is located on the inner side, whereby the intended fireproof glass plate is obtained. The resultant fireproof glass plate does not cause clouding by penetration of the components of the glass in contact with the sodium silicate layer into the sodium silicate, and maintains superior light transmittability for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fire-retardant glass plate of the laminated glass plate type, which has a solid phase of hydrated sodium silicate as an intermediate layer.

Glass plates are vulnerable to flames and heat, so they have the disadvantage of breaking when exposed to flame or heat - however, if the heat is applied gradually or if they are made of quartz glass, they will break. However, it has poor insulation properties. It is dangerous if a glass plate breaks due to flames and heat and falls, so wire mesh is embedded in the glass plate to prevent it from falling even if the glass breaks. It also has the disadvantage of low light transmittance.

On the other hand, it is transparent under normal conditions, but when heat is radiated due to fire etc., the intermediate layer foams and forms a heat insulating layer, and even if the glass plate breaks, it will fall because it is glued to the heat insulating layer. A laminated glass type fire-resistant glass plate was published in 1977-13.
It was proposed in Publication No. 04, etc., and is commercially available under the trade name ``Pyrostop'' by West German company Detag.

These fire-resistant glass plates consist of laminated glass plates with a solid phase of hydrous sodium silicate intermediate 1→.

According to the above patent publication, 8i of sodium silicate in the intermediate layer
The molar ratio of Qz/Na2o is 6.3 and the J water ratio is 25 to 65.
One weight is considered to be one weight, and the thickness of the middle layer is 1 to 10 pieces.

It is necessary that these fire-retardant or fire-retardant glass plates do not reduce their translucency even if they are used for a long period of time under normal conditions. As a result of tests conducted by the present inventors on commercially available fire-retardant glass plates such as 7t et al., it has been found that cloudiness occurs at temperatures between 70 and 140 E in weather resistance tests and tests under high temperature and high humidity conditions. In such a state, it is difficult to maintain excellent translucency during the hanging period, and the product cannot have sufficient commercial value.

The purpose of the present invention is to have extremely little cloudiness even after long-term use.
Moreover, it is an object of the present invention to provide a fire-retardant glass plate that fully exhibits its fire-retardant function in the event of a fire.

The fire-retardant glass pane according to the invention comprises at least two glass panes with an intermediate layer of sodium silicate between them. In the fire-retardant glass plate having 5i of sodium silicate in the intermediate layer,
This invention relates to a fire-retardant glass plate characterized in that the molar ratio of Oz/NzO is &7 to 3.9.

Furthermore, in a preferred embodiment of the present invention, 1! It is characterized by containing sodium silicate in a 5i02/Na2O molar ratio with an lj member of 5.7 to 5.9, 20 to 35% by weight of water and 7 to 20% by weight of glycerin.

The fire-retardant glass sheet according to the present invention is characterized by the composition of its intermediate layer. One of them is the 5i of sodium silicate contained in
The molar ratio of 02/Na2O is 6.7 to 3.9.

Sodium silicate solution is commercially available as water glass, and its quality is also specified by the JIi9 standard. Products No. 1, No. 2, No. 3 and No. 4 are S i 02 / Na2, respectively.
The molar ratio of 0 is approximately 2, 2, 5, 3 and 4. The sodium silicate used in the present invention falls within the category of No. 4 water glass. In conventional fire-retardant glass plates, No. 3 water glass has been used because when the glass foams due to flames and heat, its volume increases significantly and a thick heat-insulating layer is formed, providing sufficient fire resistance. However, this one using No. 3 water glass has one drawback: it becomes cloudy after long-term use. Note that No. 2 water glass was not used because its viscosity was too high and it was difficult to inject it between the glass plates.

As a result of the inventor's investigation into the cause of cloudiness in fireproof glass plates using sodium silicate, the main cause was found to be due to the glass in contact with the sodium silicate layer melting into the sodium silicate layer. I discovered that it is something.

To prevent glass melting as much as possible, use silicic acid (IJ)
It is necessary to reduce the alkaline content and moisture content of the aluminum layer as much as possible. As a result of further study, the present inventors found that sodium silicate also has a 5i02/Na2O molar ratio of 57 to '5.
．． 9, it was discovered that, in combination with the effects of other conditions, it was possible to prevent broken glass from falling due to flames and heat radiation, and to significantly reduce clouding due to long-term use. This is considered an important requirement of the present invention.

Furthermore, as mentioned above, low moisture content in the intermediate layer is an important requirement for preventing clouding. However, since this moisture is a raw material that forms a foam layer during flame and heat radiation, it is necessary to add the required amount of moisture. Therefore, in the intermediate layer of the laminated glass of the present invention, the moisture content II is 20 to 3
5% by weight. The water content of No. 4 water glass according to the J Engineering S standard is approximately 70 inches, so when using this water glass, it is necessary to apply, pour, inject, or fill the glass plate (in some cases, it must be dried before application). ), but it must be dried to the above concentration.

In addition, glycerin is added to the intermediate layer of the present invention as an auxiliary agent.
It is optimal that the content is 20% by weight (ratio to the total amount of the intermediate layer containing glycerin).

Glycerin has the effect of suppressing the activity of alkaline components in the intermediate layer. Moreover, when this fireproof glass plate is heated and the intermediate layer foams, the flow of the foam can be reduced and the force for holding the glass pieces can be increased. Similarly, as an adjuvant,
Glycerin is the best choice, but as a result of considering an intermediate layer in which sugar was added along with glycerin, we found that the intermediate layer cracked after foaming. It was found that the pieces tended to be difficult to fall off.Next, representative examples and comparative examples from the above experiments will be described.

Four types of water glass shown in Table 1 were used as the 8 sodium silicate liquids.

Table 1 Glue a grid of height 5 mm and width 5 W + around a glass plate of 300 x 300 mm and 5 thicknesses, add or not add the required amount of glycerin to the thorium silicate solution in Table 1, and 1502 was soaked into the top surface of the glass and fixed horizontally in a constant temperature and humidity chamber. When this glass plate was dried under certain conditions, a transparent water glass film was formed in each case.

The periphery of the glass plate having the dried water glass film produced in this manner was cut off to obtain a 254 x 254 size glass plate. Two glass plates of the same type were immersed in boiling water, quickly brought together, and the excess water was removed from between the plates and pulled up.

This operation took about 10 seconds. All of the finished laminated glass plates were transparent and free of bubbles. Table 2 shows the specifications and drying method of the intermediate layer of the laminated glass plates of Example 1.2 and Comparative Example 1.2 produced in this manner.

Table 2 Dry vermillion material 1 was dried at 90°C and 80% relative humidity for 6 hours, then at 90°C and 50% relative humidity for 16 hours, and then at 10°C.
/ 10 minutes of slow cooling. Drying conditions 2: After drying for 6 hours at 190°C and relative humidity of 80°C, slow cooling was performed at 10°C for 10 minutes. Of course, the raw materials used to prepare the samples in Table 1 are sodium silicate in the same molar ratio.

The four types of laminated glass plates prepared in this way were mounted on a frame having openings the size of the four glass plates, and the JIS
A 131102 grade heating was performed for 15 minutes, and the condition of the laminated glass plate after the test was observed with the naked eye.

In addition, the periphery of these laminated glass plates was sealed with 1m thick butyl tape, covered with 0.1cm thick aluminum foil, and placed in a thermostatic oven at 70℃ for a long period of time to maintain the transparency of the glass. Changes in sex were observed. Changes in haze value were measured using a commercially available haze meter.

Established results (1) Heating test results Among the test glass plates, those to which glycerin was added had less flow of bubbles.1. It was recognized that the glass adhesive strength of the middle 1'L4 layer was strong. (2) Temperature and humidity resistance test results The results of holding at 70°C are shown in Figure 1. As is clear from Figure 1, there is a tendency for the change in haze value to increase over time due to the decrease in the molar ratio of 5i02/Na2O in the intermediate layer and the absence of glycerin, and the haze value increases significantly due to an increase in moisture content. It is permitted to do so.

Therefore, by meeting the requirements of the fire-retardant glass plate of the present invention, it is possible to exhibit fire-retardant functions and reduce clouding caused by long-term use under normal conditions.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the results of temperature and humidity resistance tests of fireproof glass plates according to the present invention and comparative examples.

Claims (1)

[Claims] Box 1) A fire-retardant glass plate having an intermediate layer of sodium silicate between at least two glass plates, wherein said intermediate layer contains sodium silicate 5i02/N20.
A fire-retardant glass plate having a molar ratio of 57 to 3.9. (2) A fire-retardant glass plate having an intermediate layer of hydrous sodium silicate between at least two glass plates, wherein the intermediate layer comprises sodium silicate with a 5102/NaO molar ratio of 3.7 to 59, 20 to 35. Qjti% moisture and 7
A fire-retardant glass plate according to claim 1, characterized in that it contains ~20% by weight of glycerin.