JPH035455B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a sealing material that is applied to joints such as overlapping parts and joints of long board materials such as wood, cement, metal, and gypsum boards used in buildings and structures to prevent the infiltration of rainwater, etc. The present invention relates to a coating method. Conventionally, construction methods have been adopted in which walls, etc. are constructed by joining long boards such as plaster, metal, and wood in the width direction, in addition to cement-based materials made from hydraulic cement and asbestos. ing. On this occasion,
The joining of the above-mentioned plates is carried out using various combination methods such as butting, interlocking, and bonito provided on the sides in the longitudinal direction. An elastic sealant is applied to absorb the effects of displacement. The application of the above-mentioned sealant to the joints of the plate materials is usually carried out as follows. For example, when applying a two-component polyurethane foam sealant, two raw material components are stored in two tanks 1 and 2 of the sealant applicator shown in FIG. 1, and are pumped by gear pumps 1a and 2a, The mixture is introduced into the mixing chamber 3 through introduction pipes 4a and 4b of the mixing head 4 attached to the mixing chamber 3. The introduced raw material components are sufficiently stirred by a mixing rotor 6 which is rotated at high speed within the mixing chamber 3 by a motor 5, and are continuously discharged from the tip of a nozzle 7 attached to the mixing chamber 3. While moving the plate 8 or the nozzle, move the real part 8.
Apply in a straight line on areas such as a. By the way, if the viscosity of the sealant discharged from the nozzle is low, the sealant 9 applied to the plate 8 will flow and spread in the width direction, as shown in FIG. It was difficult to obtain a bead shape. Here, the reason why the bead shape of the sealant is required is that in the case of the above joint example, when the male and female seeds are overlapped with the sealant interposed therebetween, the sealant extrudes from the nozzle. This is because the sealant is sufficiently foamed, the viscosity increases, the height of the sealant increases, and the high elasticity of the sealant sandwiched between the plates provides a high sealing effect. On the other hand, if the sealant discharged from the nozzle does not contain enough bubbles and has a thin shape, the viscosity of the sealant is low. No effect is obtained. At this time, if a large amount of sealant is used, even if it flows in the width direction, it can be formed to the same height as the raised one, but since it does not contain enough bubbles, it is hard and has low elasticity. The sealant is difficult to compress at the place where the boards are joined, causing problems in joining the male and female parts of the boards. Furthermore, since a large amount of sealant is used, it is not economical, and furthermore, the area to be applied to the plate material becomes wide, and the sealant may protrude from a predetermined position, which may impair the appearance. In view of the above circumstances, it is an object of the present invention to provide a method for applying a sealant in which the sealant applied from the nozzle tip to the upper surface of a plate retains a raised bead shape, and the gist thereof is as follows: A method of applying a sealant in which the sealant is applied to a plate material by discharging the sealant from a nozzle of a mixing chamber of a sealant applicator, the method includes discharging the sealant as a foam-containing material from the nozzle. The present invention will be explained in detail below. The method of the present invention is to make the sealant into a bubble-containing state beforehand to increase the apparent viscosity immediately after discharge and apply it to the plate, thereby maintaining the raised bead shape of the sealant. It is. That is, in the present invention, the type and amount of the foaming agent, the length of the nozzle, the discharge speed of the sealant, etc. are varied and combined as appropriate, and the foaming is almost completed by the time the sealant leaves the nozzle. By applying this to the plate material, it prevents it from flowing widely and creates a raised bead shape. The method of the present invention will be specifically explained below by showing an example. Polyol, the raw material for two-component polyurethane foam sealant, water: 0.5 part, amine catalyst 22
Isocyanate: 15.8 parts, polyol main component material mixed with 0.05 parts of metal catalyst: 100 parts
were continuously supplied to the mixing chamber 3 of the sealant applicator by the gear pumps 1a and 2a, and thoroughly stirred by the mixing rotor 6.
60g/min using 250mm, 450mm nozzle 7
The foamed state is discharged at a speed of 10m/
It was applied from above to the real part 8a of the plate material of min. After the sealant had hardened, the height and width of the beat 9 and the watertightness of the board were measured. The results are shown in Table 1.

[Table] As is clear from the above results, when the discharge speed is high and the nozzle length is short, the residence time of the mixed sealant is short, so the sealant discharged from the nozzle tip does not contain enough bubbles. First, due to its low viscosity, it spreads in the width direction, making it impossible to obtain the desired bead shape. Therefore, watertightness is also poor. On the other hand, as the length of the nozzle 7 increases, the sealing material discharged from the nozzle tip becomes sufficiently foam-filled and has a higher apparent viscosity at the time of discharge. A bead shape with a height of However, if the length of the nozzle 7 is made extremely long,
There is a possibility that the sealant will begin to solidify within the nozzle 7, and the sealant will not be discharged smoothly. Furthermore, if the amount of catalyst added increases,
If the isocyanate is made into a prepolymer, the optimum length of the nozzle 7 for discharging the sealant as a foam-containing material becomes shorter. In other words, by considering and combining the amount of catalyst added, the inner diameter and length of the nozzle, the discharge speed, the feed speed of the plate material, etc., it is possible to ensure that the sealing material discharged from the nozzle is sufficiently encapsulated and does not solidify. This results in a state in which the beats do not start, and beats with different cross-sectional shapes or sizes are obtained. Furthermore, the required height of the beet differs depending on the plate material to be coated, and if the width is narrow relative to the height, it becomes unstable. Therefore, by first determining the required height depending on the type of plate material, and then selecting the bead shape by changing the above conditions so that the width is 2 to 4 times the height, there will be no waste of raw materials. A stable sealing material with good watertight performance can be obtained. As described above, in the method of the present invention, the sealant is applied to the plate by being discharged from the tip of the nozzle as a foam-containing material with a high apparent viscosity when discharged.
The desired raised bead shape of the sealant can be obtained, and the effect of completely preventing the intrusion of rainwater etc. at overlapping parts and joints in buildings and structures can be obtained.

[Brief explanation of the drawing]

Figure 1 shows the flow of a sealant applicator that is generally used to apply two-component sealant, and Figures 2 and 3 show how the sealant is applied to the top surface of the plate from the nozzle. , second
The figure shows a wide range of beat shapes, and FIG. 3 shows a desired beat shape. 3... Mixing chamber, 4... Mixing head, 6... Mixing rotor, 7... Nozzle, 8... Plate, 8a... Real part, 9... Sealing material beat.

Claims (1)

[Claims] 1. A method of applying a sealant in which the sealant is applied to a plate by discharging it from a nozzle of a mixing chamber of a sealant applicator,
A method for applying a sealant, comprising discharging the sealant as a foam-containing material from the nozzle.