JPS6058021B2 - insulation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a urea-formaldehyde resin foam (hereinafter abbreviated as "UF foam").

), and particularly relates to an improved method for reducing formaldehyde odor. In recent years, J-Ohm has been in the spotlight as a residential insulation material in the energy-saving era because it is inexpensive, combustible, and can be foamed on-site.

Sweat foam is usually constructed using the in-situ foaming method.
Formaldehyde is released during the drying process of the foam after construction, and its toxicity to the human body has become a problem.

Although the amount of formaldehyde generated can be suppressed to some extent by changing the formulation of the sweat foam or the foaming conditions, this method is still insufficient in its suppression effect.

As a result of intensive study on improving construction methods to reduce formaldehyde released after construction, the inventor of the present invention discovered that one or more of urea, thiourea, or ammonium chloride was added to the inner wall before construction of UF foam. Aqueous solution (hereinafter simply referred to as "aqueous solution of urea etc.")

), the formaldehyde generated over a long period of time during the drying process of the foam after UF foam construction is absorbed by urea, etc., and as a result, the concentration of formaldehyde can be significantly reduced. discovered this and completed the present invention. That is, in the insulation construction method using UF foam, the present invention applies an aqueous solution such as urea to the front or back surface of a water vapor permeable interior material, and then
This is a wall insulation construction method characterized by the construction of F-form.

The insulation method using sweat foam is carried out as follows.

Aqueous solution of urea-formaldehyde initial condensate (hereinafter referred to as “
Using a foaming gun for UF foam commercially available from West Germany's Schiaumchemy Co., Ltd., UK BIP Co., Ltd., etc., the cured liquid is sprayed onto the cured liquid, which has been foamed by blowing air into it. A wet UF foam obtained by spraying and mixing a resin liquid from a nozzle is injected or sprayed into the space to be insulated.

After construction, the foam is usually left to harden and dry. The resin liquid is produced, for example, in the following manner.

Water is added to urea and formalin as necessary, and the mixture is initially reacted at 80 to 95°C near neutrality. When the reaction has progressed to a certain extent, the pH is adjusted to continue the reaction, and at the end of the reaction, a small amount of urea is added to reduce unreacted formaldehyde. Dilute with water as necessary to adjust solids content. Note that modified products in which part of the urea is replaced with phenol, melamine, etc. can also be used. As the curing liquid, an aqueous solution containing a curing agent, a foaming agent, and an auxiliary agent is used.

Examples of curing agents include acidic substances such as phosphoric acid, sulfuric acid, acetic acid, and P-toluenesulfonic acid; examples of foaming agents include alkylaryl sulfonates, higher alcohol sulfate ester salts, and alkylphenol/ethylene oxide adducts. Examples of auxiliary agents include polyethylene glycol, polypropylene glycol, polyvinyl alcohol, etc. as hydrophilicity imparting agents, and salts such as calcium and magnesium as water quality conditioners. Water vapor permeable interior materials are moisture permeable wall materials used for interior decoration, and include dry materials and wet materials.

Examples of dry materials include wood, plywood, decorative plywood, fiberboard, organic materials such as particle board, gypsum board, wood wool cement board, asbestos slate, asbestos charcoal mag board, asbestos silica board, valve cement board, etc. There are inorganic materials. Usually, these materials are surface-finished with decorative materials such as decorative paper, cloth, thin plates, paints, and fiber wall materials. Examples of wet materials include plaster, gypsum plaster, dolomite plaster, mortar, Japanese wall materials, fiber wall materials, and the like. Aqueous solutions such as urea are specifically urea aqueous solutions,
Refers to an aqueous thiourea solution, an aqueous ammonium chloride solution, or a mixture of two or more thereof. Application of aqueous solutions such as urea,
This can be done with a spray gun, brush, roller, etc.

Theoretically, the amount of aqueous solution such as urea applied should be equal to or greater than the equivalent amount of formaldehyde generated, but in reality, the efficiency of formaldehyde collection must be taken into consideration, and It is desirable to use it in large excess. Note that the concentration of the aqueous solution such as urea can be freely selected, and a third component such as methanol can be mixed as necessary. 1 Form construction methods include injection method and spraying method.

For example, the injection method is a method used for wall insulation renovation work on existing houses. A hole is drilled into a hollow wall from the inside wall of the house, and after press-fitting the wet foam that comes out continuously from a foam gun, the hole is closed. This is a way to block the problem. The spraying method is also called the cheesecloth method, and is a method used, for example, in the wall insulation work of newly built homes, and involves spraying wet UF foam from a foaming gun onto the space covered with cheesecloth. There is no particular restriction on the time from applying an aqueous solution such as urea to the front or back surface of the interior material until applying the foam.

The insulation method of the present invention is particularly useful as a insulation method for houses, but it can also be used in factories, buildings, hospitals, schools, stores, etc. other than houses.
It is also used as an insulation method for buildings such as various warehouses.

In residential applications, it is suitable for insulation renovation work on existing homes and insulation work on newly built homes, but it is particularly suitable for insulation renovation work on existing homes.

In addition to walls, it can also be used to insulate areas such as ceilings, attics, and under floors. According to the method of the present invention, the amount of formaldehyde generated over time after insulation construction can be significantly reduced without changing the formulation of the UF foam itself, the construction method, etc. Since the concentration can be suppressed to a low level, this has an extremely significant effect on improving insulation construction methods using UF foam.

The present invention will be explained below with reference to Examples.

In the examples, 1 part represents 1 part by weight. Example 1 Experimental house: 1.73m x 1.15rn on both north and south sides
We used a one-room house with 8 tatami mats in size and a window the size of .

Ceiling height from the floor is 2.4m, wall area is approximately 30d, interior volume is approximately 30m, and large wall structure (hollow thickness 105T1r!n).
Tatami flooring, interior 9-layer gypsum board, exterior cement mortar, ceiling decorative gypsum board, 100-thick glass wool. The resin solution and curing solution for tumor foam were prepared as follows.

Preparation of resin liquid: While stirring and mixing 36.7 parts of urea, 75.4 parts of 37% formalin, 3 parts of water and 0 parts of 24% ammonia water,
The reaction was carried out at around 90°C for 3 to 1 hour.

The pH was adjusted to 4 to 5 by adding 40% formic acid, and after further reaction for 1 hour, the pH was adjusted to 8 with 20% caustic soda.

After adding 42 parts of urea and reacting at 65°C for 30 minutes,
The reaction product obtained by immediate cooling was diluted with the same volume of water to obtain a resin liquid. Preparation of hardening liquid: After stirring and mixing 13.4 parts of 85% phosphoric acid, 8.3 parts of sodium branched dodecylbenzenesulfonate, and 32 parts of a stabilizer, the mixture was diluted with water to a volume ratio of 1 mol. did.

An aqueous urea solution was spray-painted on the surface of the interior gypsum board of the experimental house at a rate of 10 g/d of urea.

In addition, on the interior plasterboard, there are 18 diameter
Trgn(7)UF' foam injection holes were drilled. Next, the above-mentioned resin liquid and curing liquid were loaded into the tank of a foaming machine, and UF, commercially available from BIP, UK, was added at a volume ratio of 1:1.
It was introduced into a foaming gun, and at the same time, air was blown into it to foam it, and it was injected into the injection hole through a flexible nozzle connected to the foaming gun.

Resin liquid and hardening liquid flow rate each 2.5e/min, liquid temperature 22~2
After the injection was completed at 9° C. with a foam gun back pressure of 3.2 k9/CItGO, the injection hole was filled with water-based putty using a metal spatula to block the injection hole.

The formaldehyde concentration was measured almost in the center of the room over a period of one month (at a temperature of 6 to 14 degrees Celsius), and the results were as follows, which showed an extremely small value.

Moreover, almost no odor was detected. The formaldehyde concentration was measured by spectrophotometry using acetylacetone (detection limit 0.1 ppm). Incidentally, the environmentally acceptable concentration of formaldehyde is 2 ppm. Example 2 The same procedure as in Example 1 was performed except that the surface of the interior plasterboard was coated with a thiourea aqueous solution instead of the urea aqueous solution, and the following results were obtained.

Moreover, there was almost no odor. Example 3 Same as Example 1 except that the surface of the interior plasterboard was coated with ammonium chloride aqueous solution instead of urea aqueous solution.
I did exactly the same thing and got the following results.

Moreover, there was almost no odor. Furthermore, an aqueous solution containing two or more of urea, thiourea, or ammonium chloride was applied and tested using the same test method as in Example 1, and almost the same results as in Examples 1 to 3 were obtained.

Comparative Example In Example 1, the coating of the urea aqueous solution on the surface of the interior gypsum board was omitted, and the rest was carried out in the same manner as in Example 1.

Claims (1)

[Claims] 1. In the insulation method using urea-formaldehyde resin foam, an aqueous solution of one or more of urea, thiourea or ammonium chloride is applied to the front or back surface of a water vapor permeable interior material, and then the urea-formaldehyde resin foam is applied. An insulation construction method characterized by construction.