JPS6158621B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for insulating walls, and in particular, to a method for insulating walls, and in particular, a method for improving the thermal insulation of walls.
This article relates to a heat insulation renovation method for existing buildings using formaldehyde resin foam.

Insulation renovation work for existing buildings involves insulating and renovating buildings that have already been completed or buildings that are already in use, but there has been no convenient construction method. Conventionally, the method used was to inject fibrous materials such as waste paper pulp and glass fiber, but as is well known, wall constituent materials such as (span) pillars, sills, rims, etc. There were wiring and piping such as electric conduits, electric wire cables, gas pipes, etc., and there were some areas that would not be filled by simply blowing, and the insulation was insufficient. In addition, these fibrous materials have a low resistance to air circulation, and the air circulation may reduce the heat insulation effect.

In order to improve these drawbacks of conventional methods,
A method of insulating hollow walls by injecting urea-formaldehyde resin foam (hereinafter referred to as urea foam) was investigated. However, since urea foam generates a bad odor during the foaming and curing process, it was considered impossible to inject urea foam inside existing buildings. Therefore, in the past, urea foam was used only in newly constructed buildings.

An object of the present invention is to provide a method that solves this problem of bad odor and allows urea foam injection work to be carried out even in existing buildings.

According to the present invention, as a wall insulation method that can achieve this purpose, inside a building,
A method comprising making a hole in at least one side of a wall having a hollow part, using this hole as an injection hole and injecting a urea-formaldehyde resin foam to fill the hollow part and plugging the injection hole, in particular , A method of using, as the urea-formaldehyde resin foam, an aqueous solution of a urea-formaldehyde initial condensate having a free formaldehyde concentration of 1% or less, a foamable curing liquid, and a foam obtained by foaming urea with air; , a method using a stopper made of cork is provided.

In the present invention, the reason why the injection hole is made only inside the building is to avoid leakage of rainwater.
This is also to prevent the waterproofing work done on the outer wall from being destroyed by drilling the holes. Naturally, the method of the present invention allows construction work to be carried out inside a building, so the progress of the construction work is not affected by the weather.

In a preferred embodiment of the present invention, urea foam injection holes with a diameter of about 10 to 30 mm are installed in the walls of buildings that require insulation renovation.
Drill a hole reaching the hollow part of the wall with a size of mm, preferably 14-18 mm. The location and number of injection holes are determined by the spacing between the studs arranged inside the wall. This (ma) pillar and (ma)
If the distance between the pillars is 1000mm or less, make one or more injection holes between the pillars. Preferably, injection holes are formed in the vertical direction of the wall with an interval of 200 to 1000 mm between the holes.

In traditional Japanese houses, this (ma) pillar and (ma)
Generally, the distance between the pillar and the pillar is 600mm or less. In this case, injection holes are made in a row in the vertical direction of the wall between each (span) pillar to (span) pillar at intervals of 450 to 700 mm. The distance between the (middle) pillars and (middle) pillars is 100
If the diameter exceeds mm or if there is a hollow wall without studs, make injection holes in one or more places. Preferably, the distance between holes is
Drill an injection hole of 200 mm to 1000 mm over the entire surface of the hollow wall. If the distance between the holes is less than 200 mm, urea foam may overflow from the adjacent hole before the hollow part of the wall is filled, contaminating the construction site and making construction difficult. Furthermore, if the injection holes are opened at intervals wider than 1000 mm, the resistance when injecting the urea foam will be large and the wall material may be damaged.

The method of injecting ureaform is as follows. For example, inject from one hole, stop the injection when the urea form reaches the next hole, move to the next hole, and start the injection again. By doing this, the urea foam injected later will spread into the other urea foam while biting into the urea foam injected earlier. By repeating this method, it is possible to fill the entire wall while tightly interlocking the urea foams.

Specifically, the following methods are available as convenient methods.

First, there are two methods for pouring into a wall where studs are less than 1000 mm long: (1) moving horizontally while pouring, and (2) moving vertically while pouring. (1) The method of moving laterally while injecting is as follows:
Since the pillars can be used as partitions during injection, there is no need to strictly control the curing time of the urea foam, which is convenient. Starting from the lowest injection hole, when the urea form reaches the hole next to the top, injection is stopped, and the injection is started by moving to the next lowest injection hole, which is separated by a pillar. As before, when the urea form reaches the hole next to the top, stop injecting it and transfer it to the next hole. Repeat this operation until all the holes at the bottom are injected. Return to the original position, move to the hole above (the one next to the top), and inject in the same way as you did for the bottom row. In this way, inject from bottom to top. When you reach the top, do the following: In areas where the wall reaches the attic, continue injecting the urea foam until it reaches the attic. In addition, in places where the upper part of the wall is blocked by beams or frame materials and there is no place for air to escape, drill a hole within about 30 mm below these blocks. Use this hole as a hole for venting air and checking filling. That is, the injected urea foam is injected until it overflows from the hole for checking filling. If this hole is not present, the wall will swell during injection, and in the worst case scenario, the wall may be destroyed. On the other hand, (2) method of moving vertically while pouring takes less time to harden;
For example, this is a convenient method when the time can be controlled within about 30 seconds. When the urea form reaches the hole next to the top for the first time from the bottom row, stop the injection, move to the hole next to the top, and restart the injection. Repeat this to fill the entire wall. When injecting into the top hole, follow the method described above.

Next, the injection method for walls without (student) columns or walls with (student) columns exceeding 1000 mm is
It is almost the same as the wall that exists below. That is, during injection, when the urea foam reaches the hole adjacent above and next to the side, the injection is stopped, and the injection is performed again by moving to the hole next to above or next to the side. When repeating this process to fill the entire wall and injecting into the top hole, follow the method described above. The injection pressure of Uriaform is 4
Kg/cm ² G or less is preferable; if it is larger than this, it may overflow from the injection hole or destroy the wall. The urea foam in the present invention is particularly preferably a urea foam made by foaming an aqueous solution of a urea-formaldehyde initial condensate having a free formaldehyde concentration of 1% or less, a foamable curing liquid, and urea with air.

Urea with free formaldehyde concentration below 1%
The formaldehyde initial condensate aqueous solution (hereinafter, this urea-formaldehyde initial condensate aqueous solution is abbreviated as resin liquid) is a resin liquid in which formaldehyde remaining in the resin liquid is 1% or less by weight. Such a resin liquid can be obtained, for example, by adjusting the molar ratio of formaldehyde and urea, which are raw materials when producing the resin liquid, to a range of 1.2 to 1.6. That is, the molar ratio of formaldehyde and urea is set to 1.2 to 1.6, and the reaction is carried out with a weakly alkaline aqueous solution together with the secondary raw materials.Then, the reaction is further carried out in a weakly acidic state, and then the pH is adjusted, and as necessary. This is a resin liquid obtained by dehydration and concentration. The free formaldehyde concentration in the resin liquid is
Determined by the method for measuring free formaldehyde specified in JIS K6801. If the free formaldehyde concentration determined by this method is 1% or less, it can be used as the urea foam raw material of the present invention. If it exceeds 1%, the amount of formaldehyde emitted from the obtained urea foam will increase rapidly, and the strong formaldehyde odor will make it unsuitable for heat insulation renovation of existing buildings.

The foamable curing liquid in the present invention is an acidic aqueous solution containing a surfactant. There are no particular restrictions on the foaming curing liquid. (2) Acidic substances such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, boric acid, ammonium chloride, ammonium sulfate, aluminum sulfate, monohydrogen phosphate, organic acids, etc. as a main component. can be used.

There are no particular restrictions on the quality of urea. It may be of normal quality used for industrial purposes or fertilizers. The amount of urea added is 15 parts by weight or less, more preferably 5 to 12 parts by weight, per 100 parts by weight of the solid content of the resin liquid (non-volatile residue remaining after drying the resin liquid at an ambient temperature of 120°C for 3 hours). Parts by weight range. If more than 15 parts by weight of urea is added, it will not only significantly interfere with the foaming properties of the foamable hardening liquid and make it difficult to foam, but also reduce the strength of the resulting urea foam, which will eventually exist as a foam. You won't get any more. This urea is used by being mixed and dissolved in a resin liquid or a foaming hardening liquid. In order to save the trouble of dissolving urea, it is convenient to use an aqueous solution in which urea is dissolved in water in advance.

Uriafoam is formed by mixing and dissolving the above-mentioned resin liquid and urea into a foamable hardening liquid to make it foamable, and further mixing with air to cause foaming. That is, the resin liquid and the foaming hardening liquid are continuously supplied to the foaming machine through separate paths. In the foaming machine, air is supplied to the foamable hardening liquid, causing it to foam. A resin liquid is sprayed onto this foam to form urea foam.

The urea foam is guided through a soft tube connected to a foaming machine to an injection hole drilled in the wall. The urea foam is introduced into the wall through the injection hole, and the supply of foam is stopped when the inside of the wall is filled with the urea foam. A cork stopper is used to fill this hole back up. The advantage of using cork as a material is that although it is a solid stopper, it becomes flexible when pressure is applied. Therefore, even if the injection hole is slightly different in size, a cork stopper of one size can be used. Further, even if it is required to cut the cork stopper, it can be easily cut with a thin blade such as a razor. By using a cork stopper, the hole filling work can be performed quickly and easily in the construction method of the present invention.

Although the insulation work is completed as described above, the present invention does not in any way preclude the decorative finishing of the wall surface after filling the hole with a cork stopper.

INDUSTRIAL APPLICATION This invention is applied to the insulation construction method of hollow walls, such as a wooden building and a concrete building. As long as it has a hollow part, it can be applied not only to walls but also to ceilings, floors, doors, etc. The method of the present invention requires only three steps: drilling a hole, injecting urea foam, and filling the hole with a cork stopper, and does not require a large construction area, so insulation work can be performed quickly and easily even in occupied houses. can be done. Furthermore, the method of the present invention can be carried out in the same state where residents live, since the amount of formaldehyde emitted from the urea foam is extremely small. A further advantage is that the invention is economical and has low installation costs since there is no need to tear down walls and install insulation.

Next, the present invention will be specifically explained using examples.

Example 1 Insulation work was carried out on the wall of a house built using a conventional construction method in which the spacing between the (space) pillars and the (space) pillars 2 and 2 was 455 mm. The configuration of the wall is shown in Figure 1. The thickness of the hollow part of this wall was approximately 100 mm. An injection hole was made in the 9 mm thick gypsum flat board 3 of the inner wall between the (space) pillars and the (space) pillars 2, 2. The injection holes are located at heights of 600 mm, 1200 mm, and 1800 mm from the floor, respectively. At the bottom of the window and above the window, injection holes were made at the center of the (student) post-(student) post, below the window sill, and 150 mm above the lintel, respectively. The diameter of the injection hole was approximately 15 mm. A hole with a diameter of approximately 6 mm was drilled under the window for confirmation.

A urea foam for injection into this injection hole was manufactured as follows.

The molar ratio of formaldehyde and urea is 1.4,
A small amount of formic acid, caustic soda, diethylene glycol, and triethanolamine were used as subsidiary raw materials for reaction to obtain a resin liquid with a viscosity of 27 centipoise (B-type viscometer, measurement temperature 25°C). This was further dehydrated and concentrated to obtain a concentrated resin liquid (1) having a viscosity of 4.52 poise (B type viscometer, measurement temperature 25°C) and a specific gravity of 1.28. The free formaldehyde concentration of this resin liquid (1) is
When measured using the method specified in JIS K6801,
It was 0.4% by weight. As the foamable curing liquid 2,
The main components are sodium alkylbenzenesulfonate and phosphoric acid, and the specific gravity and viscosity at 25℃ are respectively
We prepared 1.079 and 4.3 cp and PH of 1.4. As urea (3), industrial urea was dissolved in water to prepare an aqueous urea solution having a specific gravity of 1.12 at 25°C. Resin liquid (1) was diluted to 100% by adding 50% water and placed in a pressurized container. Put the foaming curing liquid (2) 10 and the urea aqueous solution (3) 10 in another pressurized container, and add water to make 100. The amount of urea added at this time was 10.7 parts by weight based on the solid content of the resin liquid. Air pressure was applied to the resin liquid and the foaming hardening liquid, the same flow rate was supplied to the foaming machine, and air was further introduced into the foaming hardening liquid to form urea foam. The air pressure of the foaming machine is 3.1Kg/cm ²
It was G. Bulk density of this urea form (=weight of urea form/volume of urea form)
(Kg/m ³ ) was 44.4Kg/m ³ . Cure time was 45 seconds.

Next, an injection nozzle attached to the tip of a soft tube connected to a foaming machine was inserted into the injection hole in the wall, and the urea foam 10 described above was injected. Injection was first performed to the bottom injection hole, then to the middle and upper tiers.

Finally, insert a cork plug 1 into the injection hole after injection.
Did. This stopper was hammered and embedded into the wall. When the cork stopper was too large compared to the hole diameter of the injection hole and could not be embedded into the wall, the cork stopper was cut along the wall with a thin-bladed knife.

The insulation work was thus completed, but no formaldehyde odor was detected in the room either during or after the work. In addition, we attempted to measure formaldehyde concentration using a Kitagawa vacuum method gas detector, but the detection limit (1 ppm) was detected in the room both during and after construction.
and could not be measured.

Example 2 Insulation work was carried out on a concrete wall in which the distance between the vertical rim and the vertical rim 7, 7 was 455 mm. The configuration of the wall is shown in Figure 2. The thickness of the hollow part of this wall is approximately
It was 50mm. An injection hole was made in the 2.7 mm thick plywood 9 of the inner wall in the middle of the vertical furring edges 7, 7. The position of the injection hole was the same as in Example 1.

Uriaform was manufactured as follows.

The molar ratio of formaldehyde and urea is 1.6,
A small amount of formic acid, caustic soda, diethylene glycol, and triethanolamine were used as subsidiary raw materials to react, and a resin liquid (1) having a viscosity of 43 centipoise and a specific gravity of 1.20 was obtained. The free formaldehyde concentration of this resin liquid (1) was 1.0%. The same foaming curing liquid (2) and urea (3) as in Example 1 were prepared.
Water was added to 70% of stem fat liquid (1) to dilute it to 100%, and the mixture was placed in a container. Foaming hardening liquid (2) 10 and urea aqueous solution
(3)Put 11.2 in another container and add water to 100
And so. The amount of urea added at this time is 12% of the solid content of the resin liquid.
It was by weight. The resin liquid and the foaming hardening liquid were each supplied to a foaming machine at the same flow rate using pumps, and air was further introduced into the foaming hardening liquid to form urea foam. The air pressure of the foaming machine was 3.0Kg/cm ² G.
The bulk density of this urea foam was 47.1 Kg/m ³ and the curing time was 50 seconds.

Injection of the urea foam 10 and backfilling of the injection hole with the cork stopper 1 were carried out in the same manner as in Example 1.

The insulation work was thus completed, but no formaldehyde odor was detected in the room either during or after the work. We also attempted to measure the formaldehyde concentration with a Kitagawa vacuum gas detector, but it was below the detection limit (1 ppm) in the room both during and after the construction, so we were unable to measure it.

[Brief explanation of the drawing]

1 and 2 are vertical cross-sectional partial views of the wall after injecting urea foam above the injection hole; FIG. 1 shows the case of Example 1, and FIG. 2 shows the case of Example 2. Each case is shown below. In the figure, 1 is a cork stopper, 2 is a (stud) column, and 3
is a gypsum flat board, 4 is a wooden base for the outside wall, 5 is construction paper and lath netting, 6 is a mortar outside wall, 7 is a vertical rim,
8 is a reinforced concrete frame, 9 is plywood, and 10 is urea foam.

Claims (1)

[Claims] 1. Inside an existing building, make holes at intervals of 200 to 1000 mm on at least one side of a wall with a hollow part, and use these holes as injection holes to inject an aqueous solution of urea formaldehyde initial condensate containing 1% or less of free formaldehyde. , the hollow part is filled by injecting a urea-formaldehyde resin foam made by foaming a foaming hardening liquid and urea with air at a pressure of 4 kg/cm ² G or less, and the injection hole is plugged with a cork. A method of insulating walls.