JPS62136277A - Method for regulating humidity of building - Google Patents

Abstract

PURPOSE:To make it possible to automatically adjust humidity in a building, by applying the spray working of hydrophilic foam comprising a specific composition. CONSTITUTION:A stock material is prepared by mixing 10-100pts.wt. of water with 100pts.wt. of a prepolymer obtained by reacting polyoxyalkylene polyol containing at least 50% or more of an oxyethylene group and having a hydroxyl value of 20-80mgKOH/g with diphenylmethane dissocyanate. If necessary, a foam control agent, a plasticizer and a solvent, etc., are added to prepare a stock mixture which is, in turn, sprayed to the outer and inner surfaces of a building so as to adjust a thickness after foaming to 5-20mm to be foamed within 5-10sec and cured to form hydrophilic polyurethane foam.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling humidity in a building and a method for controlling humidity using polyurethane foam.

(Conventional technology) With the advancement of construction technology, the traditional Japanese construction method using wood as the main material has been replaced by a construction method using inorganic materials such as iron and concrete as structural materials. In addition, the use of tatami mats and other natural fiber materials for interior decoration has decreased, and synthetic resins and fibers have come to be used more frequently.

(Problem to be solved by the invention) As a result, the moisture absorption and release properties, which are the major characteristics of wood and other natural fibers, cannot be expected. During the winter, when heating is required, the warehouse becomes excessively dry, causing various problems.Also, in warehouses, humidity increases and decreases due to climate changes, which causes damage to stored goods.

In order to eliminate the effects of such changes in humidity, dehumidifiers are operated during the rainy season and humidifiers are operated during the dry winter months, but these require a large amount of energy and are troublesome to maintain.

(Means for Solving Problem 1) The present inventors have proposed a method that uses modern building materials, has the same moisture regulating effect as wood and other natural fibers, does not require complicated management, and can save energy. After considering this, we found that hydrophilic polyurethane foam is effective! This discovery led to the present invention.

That is, the present invention involves mixing a prepolymer obtained by reacting a polyoxyalkylene polyol containing at least 50% of oxyethylene groups and having a hydroxyl value of 20 to aO*KOH/S' with diphenylmethane diisocyanate and applying it to a building. Spraying is a method of controlling humidity in buildings that involves foaming.

Examples of the polyoxyalkylene polyols used in the present invention include ethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, 1,3. It is an addition polymerization of ethylene oxide or ethylene oxide and propylene oxide to a polyhydric alcohol such as +5-hexanetriol or pentaerythritol. Polymer polyols obtained by combining olefins such as acrylonitrile and styrene in these polyoxyalkylene/polyols can also be used.

In addition to the above, higher fatty acid ester polyols, polyester polyols obtained by reacting polycarboxylic acids with low molecular weight polyols, and OH such as castor oil and dehydrated castor oil
Group-containing higher fatty acid esters can also be used. Oxyethylene group content in polyoxyalkylene polyol is 50
~90% is appropriate. Below this range, hydrophilicity is low (
The humidity control function of the foam decreases. Further, the appropriate hydroxyl value is 20 to 80 mgKOH/g. If it exceeds this range, the number of closed cells in the foam increases and the area of contact with air decreases, resulting in a decrease in the humidity control function of the foam.

Diphenylmethane diisocyanate includes 4゜4' form, 2,4' form, 2,2' form and mixtures thereof,
Methylene crosslinked polyphenyl polyisocyanate, known as crude diphenylmethane diisocyanate, can also be used.

Dimers, dimers, and carbodiimide-modified products of these incyanates can also be used. When producing a prepolymer, the amount of reaction between the polyoxyalkylene polyol and diphenylmethane diisocyanate is adjusted so that the isocyanate group content of the produced prepolymer falls within the range of 5 to 20%.

When spray foaming is carried out, the mixing ratio of prepolymer and water does not need to be strictly defined as in ordinary urethane foam foaming, and the spraying operation can be carried out very easily. The mixing ratio is 10 to 10 parts by weight of water to 100 parts by weight of prepolymer.
Use 100 parts by weight.

If the amount of water is greater than this range, the stock solution will flow and a sprayed product with the desired thickness will not be obtained. If the amount is less than this range, foaming will be incomplete and the sprayed product cannot be used.

A foam stabilizer can be used as necessary to improve the dispersibility of the prepolymer and water during mixing. As the foam stabilizer, an organosilicon surfactant used in ordinary urethane foam foaming can be used.

A catalyst can also be used during foaming, if necessary. As a catalyst, a third grade aluminum catalyst and/or an organometallic catalyst commonly used for urethane foaming is used. In addition, plasticizers and solvents can be used to reduce the viscosity of the prepolymer, and for example, polymerization can also be performed.

The sprayed raw material mixture foams in 5 to 10 seconds, and if left as it is at room temperature, it hardens and becomes a hydrophilic polyurethane foam.

The physical properties of the generated foam have a density of 20 to 150 Kg/
rn', tensile strength of 1.0 to 5.0 K9/aA, elongation of 100 to 400%, tear strength of 0.5 to 2.0 Kg/bacteria, and has extremely high water absorption compared to normal urethane foam.

When spraying urethane foam, use low pressure spray equipment,
Any high pressure spray equipment can be used.

When applied to the inner surface of a building, the foam is sprayed onto walls and ceilings to a thickness of 5 to 20 μm after foaming.

After spraying on the wall and before the foam hardens, plywood, wallpaper, and other interior materials can be attached and adhered as is. It is also possible to spray it on the floor in the same way and then glue it with a carbera).

When spraying on the exterior of a building, the exterior is further covered with an exterior material, and urethane foam is used as the middle layer. Configure it. Alternatively, the hydrophilic foam of the present invention may be sprayed and foamed, and then a hydrophobic urethane or other synthetic resin may be sprayed to form a waterproof layer and a protective layer.

(Operations and Effects) The hydrophilic foam of the present invention constructed in this way absorbs or releases moisture depending on the relative humidity of the surrounding air, so it can automatically adjust the indoor humidity, and can be used for humidification and dehumidification. No need to operate the equipment.

In addition, since this hydrophilic urethane foam has communicating air bubbles, indoor air can easily penetrate into the foam, and therefore moisture can be absorbed and released efficiently.

Furthermore, since this hydrophilic polyurethane foam has elasticity, another major feature is that it can prevent damage to the interior material surface when an article collides with it.

(Example) Examples of the present invention will be described below.

Example 1 Using glycerin as an initiator, 250 parts of polyoxyalkylene triol containing 70% oxyethylene groups and 30% oxypropylene groups and 1963 parts of crude diphenylmethane diisocyanate were reacted at 55 to 60°C for 4 hours, and then NC
A repolymer containing 12% O groups was produced.

Using a high-pressure blow foaming machine manufactured by Toho Kikai Kogyo Co., Ltd., the weight mixing ratio of an 80% methylene chloride solution of this prepolymer and water was determined.
5100:60 was sprayed onto the ceiling and walls of a room in a concrete house to form a 10 mm thick hydrophilic polyurethane foam layer.

Hygrometers were installed in the rooms where this spraying was done and in the rooms where it was not done to check the humidity on rainy days. It was measured.

The humidity in the room where the construction was carried out was 60%, but the humidity in the room where it was not constructed was 86% and 0.
% N, 80 parts of polyoxyrylene diol containing 20% by weight of oxypropylene groups, and glycerin! As an initiator, 75% by weight of oxyethylene groups, 2 oxypropylene groups
A mixture of 20 parts of polyoxyalkylene triol containing 5% by weight was reacted with crude diphenylmethane diisocyanate to produce a prepolymer with an isocyanate group content of 10%.

Using a Landsburg high-pressure blow foaming machine, 100 parts by weight of an 80% methylene chloride solution of this prepolymer, 64 parts by weight of water, and 4 parts by weight of foam stabilizer SH-190 (organosilicon surfactant manufactured by Toshi Silicone Co., Ltd.) The mixture of parts was sprayed. Construction is 5.6m in width, 3.6m in depth, and 2.47FI in height.
It was sprayed on the ceiling and both walls of a room in a concrete house owned by Y. Does the raw material mixture foam in 1 minute? After completion, the mixture was left to stand overnight at room temperature to form a hydrophilic urethane foam layer with a thickness of 15 mm. Foam density is 1.05 K9/r
Ivy in RL.

A thermometer and a hygrometer were installed in a room with the same dimensions as the room where the spraying process was carried out and the room where the spraying process was not carried out. While the temperature and humidity of the room where no construction was performed was 25° C. and 90%, the temperature and humidity of the room where construction was performed was 25° C. and 60%.

Claims (1)

[Claims] A prepolymer obtained by reacting a polyoxyalkylene polyol containing at least 50% oxyethylene groups and having a hydroxyl value of 20 to 80 mgKOH/g with diphenylmethane diisocyanate is mixed with water, and the mixture is sprayed onto a building and foamed. Characteristic humidity control method for buildings.