JPH0421783B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for removing organic spray material used for repainting exterior walls in the repair work of housing complexes and other buildings. Here, examples of the spray material to be peeled off include synthetic resin emulsion sand wall spray material (JISA6909),
Synthetic resin elastic emulsion sand wall spray material Synthetic resin solution based sand wall spray material, multi-layer pattern spray material (JISA6010), what is known as Mastic A, AE, and rubber-like elastic single-layer (multi-layer) pattern spray material There are materials etc. [Conventional technology and problems] Conventionally, exterior wall coating materials containing organic materials deteriorate in physical properties over time after construction, but when repairing and renovating, they are simply washed with water, etc.
Next, it was common to finish with cosmetics such as repair finishing materials. However, with this specification, no matter how good the appearance may be, the base will deteriorate at an accelerated pace due to aging after renovation, causing serious problems such as poor adhesion. Therefore, it is not a true repair/renovation specification. In this case, the best method is to completely remove the organic spray material from the base and then repair it. Conventional peeling methods include, for example, sanding and sandblasting. However, if the area is large, it requires a lot of manpower, and the work is difficult due to noise and dust. Sandblasting is classified into two types: air sandblasting and wet sandblasting. For example, air sandblasting requires completely sealed curing due to the dust generated, and the scope of application is limited to specific locations such as swimming pools, gas tanks, oil tanks, etc. It is limited to areas such as tanks that have large premises and have little impact on others. In addition, wet sandblasting uses high water pressure.
This method uses sand of 150Kg/cm ² to 210Kg/cm ² and sucks sand from one side.
It takes 5 to 6 minutes to sand 2 m ² (expressed in the amount of work described below, it is 2 to 2.5 m ² / 1 hour per person), and it cannot be removed evenly, and the gouged part becomes a deep groove. There are serious drawbacks, such as the fact that There are also other problems, such as the sand used in this process can fill drainage ditches in urban areas, and accumulate on lawns in housing complexes, ruining the lawns. Another method has been developed that uses a commercially available stripping agent containing methylene chloride as a main component to soften and scrape off the old paint film. When such a stripping agent is applied to an organic exterior wall finishing material, it can soften the paint film extremely well.
First, use a brush or roller to apply 0.7 to 0.8
Kg/m ² of release agent is applied uniformly and left for 8 to 15 minutes until the coating becomes soft enough to be peeled off. The softened material can be easily peeled off by scraping it off with a spatula, leather cutter, etc. but,
If the base is a smooth surface such as a steel plate or an aluminum plate, it can be scraped cleanly, but on a regular concrete or mortar surface, even an apparently uniform surface has unevenness, so when scraping, it may get clogged in the recesses. The current situation is that it remains uniformly white. The method of this invention aims to solve the problems of the conventional technology as described above, and by combining a coating softening method using a stripping agent and high pressure washing, it can be done efficiently with simple equipment. This is to remove old sprayed material. [Means for Solving the Problems] The spraying material removal method for building exterior walls of the present invention is applied to organic spraying materials for exterior wall painting, and is carried out according to the following procedure. A required amount of a stripping agent containing methylene chloride as a main component is applied to the surface of the paint film of the spray material. Leave it for the required time (about 8 to 15 minutes) and wait for the paint film to soften as the remover penetrates. Using a high-pressure washer, etc., spray pressure water (approximately 30 to 300 kg/cm ² ) onto the softened surface of the paint film to wash it off. The release agent is composed of methylene chloride in a weight ratio of 70% or more (preferably 90% or more) and admixtures such as a binder, an activator, etc., and commercially available products can be used. [Example] Next, Examples 1 to 11 (see Table 1), which were carried out to confirm the effects of the method of the present invention, will be described. In addition, as a stripping agent, methylene chloride is used at a weight ratio of
A commercially available liquid release agent containing 90% or more (hereinafter referred to as Type 1) and a release agent with increased viscosity (hereinafter referred to as Type 2) were used. In addition, commercially available high pressure washers have a maximum pressure of 210Kg/cm ² and a water volume of 25/cm2.
For the nozzles, we used a direct injection type and a type that spreads the jet at an angle of 15°. Furthermore, the adhesion test was conducted using epoxy resin at 4cm x
A 4 cm attachment for adhesion testing was attached, and the adhesion strength was measured using a Kenken-type adhesion tester manufactured by Yamamoto Kageki Co., Ltd. Example 1 A type 1 release agent of 0.75 kg/m ² was applied evenly with a brush to an acrylic lysine surface that had been constructed for 10 years, and was left for 5, 10, and 15 minutes to soften the coating. This surface was scraped with a leather knife to test which one was the most flexible and most convenient for peeling. As a result, it was observed that 10 minutes ≧ 15 minutes > 5 minutes, and it is thought that about 10 minutes to 15 minutes (varies slightly depending on the temperature) is optimal. On the other hand, the surface of the peeled surface turned white as softened acrylic lysine clogged in the recesses of the concrete surface. The relationship between the required construction amount and time is 4~
4.5m ² / 1 hour per person. Also, the adhesive strength is 7.3Kg/cm ²
was gotten. Example 2 0.75 kg/m ² of type 1 release material was applied evenly with a brush to the same acrylic lysine surface as in Example 1, and after being left for 10 minutes, it was washed with a high pressure washer using a 15° angle nozzle. , 70Kg/cm ² of high-pressure water was sprayed to peel off the softened ricin. At this time, the concrete surface was uniformly exposed on the peeled surface, and no softened lysine remained at all. Construction amount is 5-6m ² /1
It was 1 hour. Furthermore, in order to check the adhesion of the peeled surface, an attachment for adhesion testing was attached after it was completely dried, and an adhesion strength of 17.8 kg/cm ² was obtained. Example 3 On the same acrylic lysine surface as in Example 1, a type 1 release agent of 0.75 kg/m ² was applied uniformly with a roller, and after being left for 9 to 12 minutes, it was washed with a high-pressure washer.
150° from a distance of approximately 20cm using a 15° angle nozzle.
The softened ricin surface was peeled off by spraying high-pressure water at Kg/cm ² . In this case, the underlying concrete surface was also gouged to a considerable extent, leaving no softened ricin and was extremely clean. Construction volume: 4.5-5m ² / 1 hour per person
It was hot. Further, after leaving the peeled surface for one day to completely dry, adhesive strengths of 17.8 Kg/cm ² and 18.3 Kg/cm ² were obtained in the same manner as in Example 1. Example 4 On the same acrylic lysine surface as in Example 1, 0.6 kg/ ^m2 of type 1 release agent was applied evenly with a roller, and then left for 8 to 12 minutes, using a high pressure washer and a direct injection nozzle. 100Kg/ ^cm2 from a distance of approximately 20cm
The softened lysine surface was gradually peeled off by spraying with high-pressure water. In this case, since it is a direct injection nozzle, 100
Even with pressure water of Kg/cm ² , the concrete surface was severely gouged and the base was seriously damaged. Furthermore, workability was also poor due to the small angle of the nozzle. However, the softened ricin was completely removed and nothing remained. The amount of work was 2 to 3 m ² /per hour per person, and the adhesive strength was 18.8 Kg/cm ² in the same manner as in Example 3. Example 5 Aging of epoxy emulsion multilayer pattern sprayed surface
Apply 1 kg/m ² of Type 2 release agent evenly with a brush to the 10-year-old product, leave it for 15 minutes, and then use a high-pressure washer and a 15° angle nozzle to remove 110 kg from a short distance of about 20 cm. /cm ² of high-pressure water was sprayed to gradually peel off the softened surface. The multilayer pattern was removed cleanly, and nothing was left on the concrete surface. The amount of construction is
An adhesive strength ^of 18.2 Kg/cm 2 was obtained under the same conditions as in Example 3 at 3.5 to 4 m ² /person for 1 hour. Example 6 Multi-layer pattern spray material RE (JISA6910), Mastic A
Type 2 stripper 1 on a 10-year-old wall
Kg/m ² was applied evenly with a brush, and then left for 12 to 15 minutes to sufficiently soften the mastic side A. Using a high-pressure washer and a 15° angle nozzle, 120 Kg/m2 was applied from a short distance of about 20 cm. The softened surface was peeled off little by little by spraying high-pressure water at ^cm2 . The mastic surface was removed cleanly, and the amount of work was 3 to 3.5 kg/1 hour per person. Further, an adhesive strength of 17.8 Kg/cm ² was obtained by the same method as in the example. Example 7 On a 10-year-old wall made of rubber-like elastic multilayer pattern spray material, 1.2 kg/m ² of type 2 release agent was applied evenly with a brush, left for 10 minutes, and then washed with a high-pressure washer for 15 minutes. Using a ゜angle nozzle, from a short distance of about 20cm
High-pressure water of 90 kg/cm ² was sprayed to peel off the softened surface little by little. The elastomer multilayer pattern was peeled off cleanly, leaving no residue. Construction amount is 2.7-3.0m ² /1
Adhesive strength was measured using the same method as in Example 3 for 1 hour.
16.9Kg/cm ² was obtained. Example 8 During the repair of an acrylic lysine exterior wall (12 years old), the part of the lower part of the window where water had passed had partially fallen off. I tested the adhesive strength of this part.
The adhesive strength was 2.3Kg/cm ² and it was necessary to remove the entire surface. Apply 0.7Kg/ ^m2 of type 1 release agent evenly, then leave it for 9-12 minutes to fully soften, then use a high-pressure washer and a 15° angle nozzle to apply low-pressure water (from a distance of 20cm). 25Kg/cm ² ) was released, and the softened surface was peeled off. At this time, the peeling was incomplete, and the softened lysine remained in the recesses, making the appearance completely dull. The construction amount was 2.5 to 3.0 m ² / 1 hour per person, and the adhesive strength was 7.5 Kg/cm ² by the same method as in Example 3. Example 9 The same acrylic lysine surface as in Example 1 was sprayed with 300 kg/cm ² of high-pressure water using a high-pressure washer and a 15° angle nozzle without using a remover to remove the lysine coating. In this case, the ricin is not peeled off uniformly,
Also, the concrete was severely gouged and the workability was improved. Construction amount: 2-2.2m ² / 1 hour per person, adhesive strength
It was 7.5Kg/ ^cm2 . Example 10 The same acrylic resin surface as in Example 1 was sandblasted (wet) without a release agent, and then 150 kg/cm ² of high pressure water and sand were applied using a high pressure washer and a wet sand gun. Spray it,
The acrylic lysine surface was peeled off. Peeling was not done uniformly, and the concrete remained completely rough, and there were large gouges in the concrete in some areas. Construction amount is 1.7~2.0m2 ^/
One person spent 1 hour, and the adhesive strength was 7.2 kg/ ^cm2 . Example 11 To check the adhesive strength of the old lysine surface, an attachment for adhesion test (4 cm x 4 cm) was directly attached to the acrylic lysine surface using epoxy resin, and the adhesive strength was 2.7 Kg/cm ² . Table 1 summarizes the above Examples 1 to 11 as a table. In addition, 30Kg/cm ² , 70Kg/cm ² , and 150Kg/cm ² for removing spray material softened with a release agent.
When comparing the high-pressure water of 70 kg/cm 2, it is considered that a high pressure of 70 kg/cm ² is almost appropriate if the type of release agent and the standing time are set to the optimum conditions. i.e. 30Kg/cm ²
With medium-pressure water, the peeled surface is white and blurred, and it is slightly better than that with a scraper. On the other hand, with high-pressure water of 150 kg/cm ² , the peeled surface is very well finished and does not leave a white residue, but it also soaks into the underlying concrete surface, making it difficult to correct the unevenness. Also, high pressure water is 150Kg/cm ²
Considering that the above is for reactionary action, it is not possible to operate the machine with one hand and work efficiency becomes worse.
It is not enough to simply increase the pressure. In other words, it was found that appropriate pressure to enable peeling with pressurized water is essential. In addition, there is not only a difference in appearance between something that has been removed using the scraper removal method and has sunk into the recesses of the cement or mortar on the exterior wall, and something that has been completely removed by spraying high-pressure water with a high-pressure washer. It can be seen from the above examples that there is also a large error in adhesive strength. In other words, from a microscopic perspective, it is thought that the softened spray material that sinks into the concave part does not participate in adhesion at all, and only the concrete base or mortar surface of the convex part is involved in adhesion. It can be seen that the degree of badness is well proportional to the degree of whiteness of the peeled surface. In addition, when repainting an old paint surface, it is thought that an adhesive strength of at least 8 kg/cm ² , preferably 10 kg/cm ² or more is required, and Table 1 also demonstrates the effectiveness of this invention. ing. (Effects of the Invention) This invention has the above-mentioned configuration, and the spraying material is softened by a release agent containing methylene chloride as a main component, and then the spraying material is washed off with pressure water using a high-pressure washer or the like. The spraying material can be removed without leaving it in the recesses of the wall surface, etc. Also, since the spraying material is sufficiently softened before being sprayed with pressurized water, the wall surface cannot be removed by force, as would be the case if you tried to forcefully remove the spraying material using only high-pressure water. There is no damage. Therefore, when repainting, sufficient adhesive strength can be obtained and complete repairs can be performed.

【table】

【table】

Claims (1)

[Claims] 1. On the coating surface of an organic spray material for exterior wall painting,
An exterior wall of a building characterized by applying a required amount of a remover containing methylene chloride as a main component, leaving the paint film for a required period of time to soften the paint film, and then spraying pressure water to wash and remove the softened paint film. sprayed material removal method. 2 The release agent is methylene chloride with a weight ratio of 70% or more,
A method for removing spray material from an exterior wall of a building as claimed in claim 1, which comprises a binder, an activator, and the like. 3. The method for removing spray material from an outer wall of a building according to claim 1 or 2, wherein the pressure water is ejected at a pressure of 30 Kg/cm ² to 300 Kg/cm ² .