JPS60171279A - thermally expandable fireproof adhesive - 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 novel thermally expandable fire-resistant adhesive that is used by filling the butt joints of inorganic plates.

Conventionally, A
Inorganic boards such as LC (autoclaved dry weight concrete) boards, foamed concrete boards, and fiber-reinforced foamed gypsum boards have come into widespread use. All of these inorganic plates have a width of 600-900III11 and a thickness of 40-1001
11L It is a plate-shaped body with a length of about 3 to 4IIl, and when in use, it is fixed one by one on a pre-erected steel frame with fasteners. In this case, as shown in Figure 1, the methods for joining the joints (2) between adjacent inorganic plates (1) (1) include the Aishakuri method (a), the Hijitsu method (b), and the fire-resistant adhesive method. There is a filling method (0), each of which has drawbacks as shown in Table 1.

Table 1 Currently, in the construction of buildings and partition work,
In order to shorten the number of passes, simplify the process, and reduce construction and work costs, various types of dry method 1, in which inorganic boards are built in, are adopted, but the above (a), (b), <O) It cannot be said that the joining method described above necessarily satisfies these demands.

In addition to the above three joining methods, the butting method (
d), but this method has not been adopted in reality.

This is because when using this type of inorganic board material, it is stipulated that it has a fire-resistant structure according to Article 2, Paragraph 7 of the Building Standards Act, and when using it for each building part or section,
Certification (or designation) l+l) marks comply with Building Standards Act Enforcement Ordinance No. 1
07, and the test methods for these fire-resistant structures are also based on the Ministry of Construction's Notification No. 2999.
A-1304F Fire Resistance Test Method for Building Structural Parts", and one of the J5 pass/fail criteria for this fire resistance test is "There should be no cracks in walls, floors, or roofs that allow flame to pass through during heating. This is because it clearly states that 0.

That is, the reason why the above three bonding methods (a), (b), and (C) are adopted despite having various drawbacks is that they are recognized as effective in the above points.

Incidentally, the fire resistance test according to JIS A-1304 is divided into the following five stages depending on the relationship between the heating degree and the heating time (In (fire resistance time)).

Fire resistance rating Maximum heating temperature ('C) 30 minute fire resistance 840 1 hour fire resistance 925 2 hour fire resistance 1010 3 hour fire resistance 1050 4 hour fire resistance 1095 The inorganic boards that make up the walls are required to have a fire resistance rating of at least 1 hour fire resistance. This performance is greatly influenced by the material of the inorganic board itself, its thickness, the method of joining the joints, the performance of the fire-resistant adhesive used for joining, etc.

In the above-mentioned Aishakuri method (a), the joints (2) between the inorganic plates (1) (1) are joined by providing a mutually bent part,
Since the gap at the vA bent joint is filled with fire-resistant adhesive (3), the retention performance of the fire-resistant adhesive during heating is reinforced, and the presence of the bent part prevents the inorganic plate from warping during heating. Even if shrinkage occurs, the generation of cracks through which flame can pass can be prevented.

In addition, according to the Labor Law (b), grooves (5) into which the grooves (4) are inserted are bored at the terminals of the inorganic plates 1) < 1), and when joining, one of the inorganic plates fli ( 5) is filled with fire-resistant adhesive (3), then fitted with the material (4), and the groove (5) of the other inorganic board is filled with fire-resistant adhesive (3) and butted together, so both grooves are The excess amount of fire-resistant adhesive (3) filled in the inside overflows and fills the bonding surface in just the right amount, and as with the above-mentioned shading method (a), the fire-resistant adhesive has a good retention performance and is suitable for inorganic boards. Even if warping or shrinkage occurs, cracks through which flame can pass can be prevented.

Furthermore, the fire-resistant adhesive filling method (C) is applied to inorganic plates (1) (1)
A semicircular groove (6) is drilled at the end of each, and when joining, apply fireproof adhesive (3) to both grooves (6) (6).
Since both the inorganic plates (1) and (1) are butted against each other, the gap between the joints is filled with excess fireproof adhesive (3) in just the right amount. In the case of this method, the above (a) and (b)
Although the retention performance of the fire-resistant adhesive is slightly inferior compared to the above method, the fire-resistant adhesive filled in the semicircular groove prevents cracks from occurring even if the inorganic board warps or shrinks to some extent. do not have.

On the other hand, Tsukutsuko no method (d) is different from the above three methods and is a simple Tsukutsu [No4#! Because it is made of steel, it is prone to cracking due to warping and shrinkage due to heating, and other reasons have led to its adoption in the field being postponed. However, even in the thrusting method (d), the performance of the fire-resistant adhesive was significantly improved, and it was possible to develop a fire-resistant adhesive that could sufficiently follow warping and shrinkage of the inorganic board. In this case, the above-mentioned drawbacks and the drawbacks caused by other methods can be overcome, and the method can be put to practical use. Moreover, this thrusting method makes it easy to process the ends of the inorganic board.
If it is put into practical use, its value will be extremely high.

The present invention was made in view of this background, and its gist is that sodium silicate (so-called water glass) is the main component, and powder fillers, fibrous fillers, and other additives are added to this. A novel heat-expandable fire-resistant adhesive comprising pumice particles added to a mixture of ingredients. ' The pumice used in the present invention is a substance called hydrated biotite or vermiculite, and its components are approximately (Mo
, Fe) a ((Si, , Ajt,)*016
) (OH) 2 ・4H20 and has a monoclinic crystal structure. It is brown in color and has a hexagonal plate shape. It has a specific gravity of 2.7 and has the property of expanding significantly when heated. This is said to be because the water contained between the molecular plates of the silicic acid (St 04 ) group becomes boiling due to heating and lifts the molecular plates, which do not return to their original state even if the temperature is lowered. Pumice is 40
It has the property of contracting slightly in the C-axis direction up to 0°C, but rapidly expanding in the C-axis direction at temperatures above that temperature.

Therefore, when using a regular fire-resistant adhesive with pumice particles or the same powder added to the joints of inorganic plates,
When heated to a temperature of 400°C or higher, the pumice particles or powder in the adhesive expands, and has the effect of closing the joint from the inside of the joint when the inorganic board warps, deforms, or shrinks due to heating. Therefore, (a) above.

Not only when the directions (b) and (c) are adopted, but also when using the thrusting method (d), there are no cracks through which the flame can pass.

However, the above method ((1)
), when used for a joint with a simple shape,
Due to the decomposition of the water remaining in the composition, the adhesive-filled area will apparently expand, but this expansion is only temporary due to the hollowing phenomenon in a portion of the adhesive. During the next 151 steps, the adhesive will sag and drip, and this drip will directly cause joint gaps, that is, cracks due to flame overload. Similarly, even if ordinary fire-resistant adhesive is used, in the case of methods (a) and (b) above, the presence of the same-shaped joints or joints prevents the adhesive from dripping, so fire-resistant adhesive The retention of the agent is improved, and together with the shape of the joint joint, the occurrence of cracks through which flame can pass is prevented.

On the other hand, when the thermally expandable fire-resistant adhesive of the present invention is used, the expansion of the adhesive-filled part is due to the thermal expansion of the pumice particles themselves, so heating occurs for a long time and the heating temperature increases. Even if the expansion progresses, the expansion will not collapse and the adhesive will not drip. Therefore, “, thrusting method (,d)
Even if the shape of the joint is simple, as in the case of a simple joint shape, cracks through which the flame can pass cannot occur.

In the case of the present invention, as the pumice, for example, crushed 8 to 15 mesh granular pumice is used.

Particles in this range are particles with a diameter of 1 to 2.5 m+++,
Mix this with ordinary fireproof adhesive and stick it on (d)
This is the particle size that gives the best performance when heated for 1 hour. Of course, these particle diameters can be arbitrarily set depending on the material of the solid board, the area in which it is used, and the method of joining the joints.

The above-mentioned ordinary fire-resistant adhesive is mainly composed of sodium silicate (so-called water glass), and contains powdered fillers such as lucium carbonate and aluminum silicate, and fibrous fillers such as asbestos and glass fiber. It contains additives, curing agents, stabilizers, surfactants and other ingredients.
It has a viscous dope-like appearance. The amount of pumice particles added to this ordinary fire-resistant adhesive varies depending on the particle size of the pumice particles, but for the aforementioned particles of about 8 to 15 mesh, 20
Parts by weight or less, most preferably in the range of 5 to 15 parts by weight. Of course, in the present invention, the amount of pumice particles added depends on the composition of these ordinary fire-resistant adhesives, especially the type and amount of powder filler, the particle size of the pumice particles, the shape of the joint, and the area of use (whether it is an external wall or a partition). ) etc., and should be arbitrarily selected by
It is not particularly limited to the above range.

Hereinafter, specific embodiments of the present invention will be explained in detail with reference to Examples.

Table 2 Composition (1) Standard composition of ordinary fireproof adhesive (parts by weight) Water glass (Baume 20°) 55 Calcium carbonate (powdered filler) 10 Aluminum silicate (〃) 15 Asbestos (fibrous filler) 5 Glass fiber () 5 Hardening agent 4 Stabilizer 2 Antifreeze agent 3 Surfactant 0.8 Antifoaming agent 0. 2. Mixture (1) Total 100.00 Put water glass into a sigma blade type kneader under low speed rotation, and add the ingredients of calcium carbonate, aluminum silicate, asbestos, glass fiber, and surfactant. A stiff mixture is obtained so that the asbestos is well dispersed.

To this are then added hardeners, stabilizers, antifreeze agents, and antifoam agents.

Although the mixture of formulation (1) can be used as it is as an ordinary fire-resistant adhesive, it is unsuitable for the above-mentioned joining method (d), that is, the poking method.

Comparative Example 1 is an adhesive with only the above formulation (1) without adding pumice, and Examples 1 to 5 are adhesives in which pumice particles as shown in Table 2 are added to 100 parts by weight of the mixture of formulation (1). This is the added adhesive.

Apply these adhesives (B) to a thickness of 60 mm as shown in Figure 2.
Using a formwork (not shown) in the center of the inorganic board (A) with dimensions of 490 x 490 ml, a thickness of 6
Coat with IllIR in an area of about 200 x 20 OF'l. These adhesives (B
) will harden.

Next, as shown in Figure 3, the vertical and horizontal dimensions are 600 x 60.
Attach this to a simple fireproof test furnace (C) with a depth of 25011n and a gas burner (D+) (
02) (D3) burns the gas flame (E). There are two upper gas burners (Dl), two middle gas burners (D
l) is 3, and the lower gas burner (D3) is 5 in total.
Heating was performed using 0 gas burners so as to follow the heating standard curve specified in Material 1 of JIS A-1304. The temperature in this case is measured by placing thermocouples F+ and F2 in the center of the inorganic plate (A) at approximately the same positions on the upper and lower ends. Additionally, in this case, as the heating progresses, the pumice in the adhesive (B) expands, causing the inorganic plate (A) and the coated surface of the adhesive (B) to separate, causing the adhesive (B) to fall off during heating. In some cases, the adhesive (B) for the inorganic board (A)
) Create a groove of approximately 5 x 5 Il 1 m in the application area.
It is best to set them at intervals.

When the temperature reaches 1 hour of fire resistance, that is, 925° C., the combustion with the gas burner is stopped, and after cooling, the shape and thickness of the mixture (B) are measured. As a result, each side (1), (2), (
The dimensions of 3) and (4) are measured in advance, and after the heating test, the dimensions of each side and the central part (5) where the adhesive drips are measured again. The original adhesive coating thickness was 6 nu++, but it expanded significantly during the heating test. This thickness expansion after heating is an extremely important characteristic and is also the greatest effect of the present invention. However, the expansion in J3 in Comparative Example 1 was beyond the apparent value and contained giant air bubbles inside, making it brittle and accompanied by large sag.

The expansion in Examples 1 to 5 was largely due to the expansion of the added pumice, so the structure was highly strong and significantly different from the comparative example, and in Example 1 (pumice content: 3 parts by weight) there was a slight sag. Other than that, no sagging phenomenon occurred.

Example 6 External wall fire resistance test According to the method specified in JIS A-1304, as shown in Fig. 5, width 6001111111 length 2,4001
1 Glass fiber reinforced foamed gypsum board (A
+ ) (A2 ) (A3 >, lightweight steel frame (CI) (C
2) Add 2.5 parts of the fireproof adhesive with a pumice content of 10 parts by weight obtained in Example 3 to (C3) using a butt joining method.
It was applied to a thickness of 1 ml and fixed with a tapping screw (D). Next, when heating was performed for 1 hour as shown in Figure 1 of JIS A-1304, the joint part (f3+)
(B2) did not catch fire at all, and when visually inspected after cooling, no cracks, peeling, or other abnormalities were observed, and the fireproofing effect of the addition of pumice was extremely remarkable.

Comparative Example 2 In the case of Example 6 above, a conventional fire-resistant adhesive obtained by the above formulation (1) was used. JI for this
When heated for 1 hour as shown in Figure 1 of S A-1304, fire eruptions were observed from the thrust joints (B+ > (B2)).After cooling, visual inspection revealed that the joints had opened and the adhesive Outflow and peeling were observed.

As described above, the present invention can achieve the intended purpose.

[Brief explanation of drawings]

Figure 1 shows a cross-sectional explanatory view of the method of joining inorganic plates,
) is the aishakuri method, (11) is the employment law, (C) is the fireproof adhesive filling method, and (d) is the thrusting method. Figure 2 is a front view of an inorganic board coated with fireproof adhesive, Figure 3 is an explanatory diagram of this installed on a simple fireproof test track, Figure 4 is the area where the adhesive is applied, and Figure 5 is the inorganic board. These are shown attached to a steel frame as an exterior wall material. Patent applicant Kuchin Seal Industry Co., Ltd.

Claims (1)

[Claims] A thermally expandable fire-resistant adhesive made by adding vermiculite particles to a mixture whose main component is sodium silicate (water glass), powdered filler, fibrous filler, and other ingredients.