JP2706992B2 - Production equipment for foaming urethane stock solution - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for producing a raw foaming urethane solution.

2. Related Art and its Problems Conventionally, as a foamable urethane stock solution, a solution prepared by adding a liquid foaming agent such as trichloromonofluoromethane at room temperature to a polyol stock solution has been proposed. When this foamable urethane stock solution is mixed with the isocyanate stock solution, the foaming agent (liquid) is vaporized by the heat of reaction, and a urethane foam having good heat insulating properties can be obtained by simply mixing the two liquids. In addition, it can be achieved simply in terms of operation.

However, trichloromonofluoromethane, which is liquid at room temperature and is often used as a foaming agent, has the property of destroying the ozone layer in the atmosphere, and its production and use tend to be prohibited. In addition, a blowing agent that is liquid at room temperature, such as water, methylene chloride, and pentane, has no danger of destruction of the ozone layer, but has a problem of poor heat insulation performance.

Dichlorodifluoromethane, which is gaseous at room temperature, has the advantage of excellent heat insulation, but has the risk of destruction of the ozone layer.Moreover, since it is a gas at room temperature, high-pressure injection is required, and equipment and operation are complicated. Not only that, since the cells are easily communicated with each other, they are not suitable for producing a closed-cell, heat-insulating foam.

The present invention has been made to eliminate such a conventional problem.

Means for Solving the Problems The present invention provides a supply part for foaming gas which is a gas at normal temperature, a supply part for silica gel particles, a supply part for a polyol stock solution and a supply part for foaming gas, silica gel particles and a polyol stock solution from each of the above supply parts. It is equipped with an adsorption mixing tower that receives the supply.The adsorption mixing tower mixes the foaming gas-adsorbed silica gel particles with the polyol stock solution at the top of the adsorption zone where the silica gel particles come into contact with the foaming gas while falling in the tower and adsorb it. The present invention relates to an apparatus for producing a raw foaming urethane solution, comprising:

In the present invention, for example, a pressure vessel is provided in the supply section of the foaming gas, and the foaming gas is stored in the vessel.
The foaming gas is a gas at normal temperature, and it is necessary that there is no danger of destruction of the atmospheric ozone layer and that the polyol be inert with respect to the stock solution. Such foaming gases include monochlorodifluoromethane, difluoroethane, and monochlorofluoromethane. Examples include difluoroethane.

The supply section of the silica gel particles is provided with, for example, a powder tank, and the supply from the tank is performed by gravity. The particle size of the above particles is preferably as small as possible in order to reduce the falling speed in the tower and increase the contact time with the gas for foaming, but if it is too small, it is miscible with the polyol stock solution, and the fine shape after mixing. Normally 20 to 150μ, preferably 30
A size of about 70 μm is used.

The supply part of the polyol stock solution is provided with, for example, a liquid tank, and the supply from the tank is performed, for example, by applying a measuring pump.

The adsorption / mixing tower is provided with an adsorption zone at the top where silica gel particles and a gas for foaming are brought into contact, and a mixing zone at the bottom where gas-adsorbed silica gel particles and a polyol stock solution are mixed. The column can be provided with a stirrer, which can be provided with a stirring blade rotating in the mixing zone or a spiral blade rotating in the adsorption zone to generate a vortex.

When producing the foaming urethane stock solution, the gas for foaming is filled in the upper adsorption zone in the adsorption mixing tower. This gas filling is desirably performed after exhausting the air in the tower. Next, a predetermined amount of the silica gel particles is continuously dropped by a small amount in the above-mentioned filled gas by its own weight. During the falling, the silica gel particles come into contact with the gas and adsorb it. Since the silica gel particles have a small particle size of about 20 to 150 μ and fall slowly in the tower, the gas can be sufficiently adsorbed to the particles by utilizing the time during the fall. In order to extend the contact time between the particles and the gas, a vortex may be formed in the gas to swirl the particles.

Silica gel particles contain the above gas at a maximum of 1 to 0.4 to 0.6.
(Weight ratio).

After the operation of adsorbing a predetermined amount of the silica gel particles, the operation of mixing the predetermined amount of the gas adsorbed particles and the predetermined amount of the undiluted polyol solution is performed in the lower mixing zone in the column. In this case, the supply of the polyol stock solution into the column may be performed before or after the gas adsorption operation.

The mixing ratio between the polyol stock solution and the silica gel particles can be selected from a wide range, and is usually set in a range such that the gas amount is about 0.1 to 0.3 mol per 100 g of the polyol stock solution.

By mixing the polyol stock and the gas adsorbed particles, a foamable urethane stock is obtained.

Catalyst for foaming urethane stock solution and isocyanate stock solution,
When mixed with various known additives such as a foam stabilizer, a cross-linking agent, a flame retardant, and a filler, gas is desorbed from the particles by the heat of reaction of the two undiluted solutions, foaming occurs, and a urethane foam is obtained.

Therefore, in the production of urethane foam, the same apparatus and operation as those of the foamable urethane stock solution using a foaming agent that is liquid at normal temperature can be applied, and the purpose of urethane foam production can be simply described on the apparatus side and the operation side. Can be achieved.

Furthermore, since a gaseous one at room temperature can be used as a foaming agent,
The risk of atmospheric ozone depletion is also eliminated.

Furthermore, since dangerous operations such as high-pressure injection are not required at all, there is no danger of deteriorating the working environment.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the apparatus of the present invention, in which an adsorption / mixing tower (1) is provided with an adsorption zone (1A) in the upper part and a mixing zone (1B) in the lower part. An exhaust line (2) is attached to the top of the tower (1), and a vacuum pump (3) and an opening / closing valve (4) on the line (2) are provided.

Outside the tower (1), a gas supply unit for bubbling gas at room temperature, for example, a pressure vessel (5) is provided, and a predetermined amount of the gas is stored under pressure in the vessel (5). Pressure vessel (5)
Is connected to the top of the tower (1) through a gas supply line (6), and a regulator (7) and an on-off valve (8) are provided on the line (6).

A supply section of silica gel particles, for example, a granular tank (9) is provided above and outside the column (1), and the tank (9) is filled with the particles. The lower end of the tank (9) is connected to the top of the tower (1) via a powder supply line (10), and a powder valve (11) is provided on the line (10). The supply of the silica gel particles from the tank (9) to the tower (1) is preferably performed in a state where contact with the outside air is prevented as much as possible in order to prevent adsorption of other components.

Further, outside the column (1), there is provided a supply section of the polyol stock solution, for example, a liquid tank (12), and the lower end of the tank (12) is connected via a liquid supply line (14) equipped with a metering pump (13). It is connected to the mixing zone (1B) in the lower part of the tower (1). Although the figure shows a case where three tanks (12) are provided, the number of installed bases is not particularly limited.

Further, a discharge line (16) provided with a metering pump (15) and a valve (17) is provided at the lower end of the tower (1). The other end of the line (16) is connected to a packaging line (not shown), for example, for packaging a product (stock solution). Alternatively, to mix with the isocyanate stock solution to form a urethane foam,
It is connected to the mixing head (not shown) of the molding device.

A stirrer (19) is provided in the adsorption / mixing tower (1), and a stirrer (21) rotated in the mixing zone (1B) is provided at a lower end of a rotating shaft (20) of the stirrer (19). I have. In the other figures, (22) is a level sensor, and (23) is a pressure sensor.

When producing the foaming urethane stock solution by the apparatus of the present invention, first, the vacuum pump (3) on the line (2)
After the air in the adsorption / mixing tower (1) is exhausted by the operation of (1) and the inside of the tower (1) reaches a predetermined degree of vacuum, the line (2)
The upper valve (4) is closed.

Next, the valve (8) on the gas supply line (6) is opened, and the gas for foaming flows from the pressure tank (5) to the line (6).
After the pressure in the tower (1) reaches a predetermined pressure, for example, normal pressure, the valve (8) is closed and the supply is stopped.

On the other hand, a predetermined amount of the undiluted polyol solution is supplied from the liquid tank (12) through the line (14) by operating the metering pump (13).
It is fed into the mixing zone (1B) in the lower part of the tower (1).

Next, a predetermined amount of silica gel particles are supplied from the powder tank (9) into the tower (1) through the line (10) with the powder valve (11) opened.

The silica gel particles supplied into the tower (1) come into contact with the filled foaming gas and adsorb it while falling under their own weight in the adsorption zone (1A) in the upper part of the tower (1), and are absorbed and consumed. The gas volume is appropriately supplied from the pressure tank (5) into the tower by opening the valve (8).

The silica gel particles that have adsorbed the gas fall into the mixing zone (1B) at the lower part in the tower (1), where they are mixed with the polyol stock solution. This mixing is actively performed by operating the stirrer (19). This mixing and stirring is continued while the falling of the silica gel particles continues, and also after the falling, and the sedimentation of the silica gel particles is started. Is prevented and maintained in a uniformly dispersed state.

As described above, in the mixing zone (1B), by mixing and stirring a predetermined amount of the gas adsorbed particles and a predetermined amount of the polyol stock solution, a foamable urethane stock solution is obtained.

The foaming urethane stock solution is taken out through the line (16) by operating the metering pump (15) to the packaging line or the urethane foam production line with the valve (17) open, and after the entire amount has been taken out. The metering pump (15) and the stirrer (19) are deactivated and the valve (18) is closed.

After the removal of the entire amount, since the foaming gas is filled in the tower (1), the supply of the undiluted polyol and the silica gel particles into the tower (1) again causes the foaming of a predetermined amount again. An urethane stock solution can be produced.

Since the foamable urethane stock solution produced by the production apparatus of the present invention contains effervescent gas-adsorbed silica gel particles, when this is mixed with an isocyanate stock solution, gas is desorbed from the particles by the heat of reaction, foaming occurs, and urethane is generated. A form is obtained.

FIG. 2 shows another embodiment of the apparatus of the present invention, in which a stirrer (19) has a spiral blade (22) for generating a vortex in the adsorption zone (1A) in addition to the stirring blade (21). There is no substantial difference from the previous embodiment except that a is provided.

In the present embodiment, since a vortex is formed in the adsorption zone (1A), the silica gel particles fall by their own weight in the adsorption zone (1A) while swirling, and the contact time with the foaming gas is reduced. Extension and, consequently, an increase in the amount of adsorption can be measured.

In FIG. 2, (a) shows a mixing head of a urethane foam production apparatus, and in this head (a), a foaming urethane stock solution from the production apparatus of the present invention and a liquid tank (b)
By mixing the isocyanate stock solution with various known additives, a urethane foam can be obtained.

When the supply of the foaming urethane stock solution to the mixing head (a) is intermittent, it was branched off from the discharge pipe (16) in order to prevent sedimentation of the silica gel particles during the stoppage of the supply, and to prevent uneven dispersion. It is preferable to circulate the foaming urethane solution using the reflux pipe (18), and the three-way valve (17a) provided also at the branch point during circulation circulates the reflux pipe (1).
8) Opened to the side.

Hereinafter, the mixing ratio of each component of the raw foaming urethane solution obtained from the production apparatus of the present invention is specifically shown as follows.

[Example 1] Polyol stock solution 100 parts by weight Silica gel particles 65.0 parts by weight (75μ) Monochlorodifluoromethane 11.6 parts by weight [Example 2] Polyol stock solution 100 parts by weight Silica gel particles 65.7 parts by weight (75μ) Difluoroethane 11.6 parts by weight [Example 3] Polyol stock solution 100 parts by weight Silica gel particles 76.7 parts by weight (75μ) Monochlorodifluoromethane 21.4 parts by weight [Example 4] Polyol stock solution 100 parts by weight Silica gel particles 60.8 parts by weight (75μ) Difluoromethane 10.1 parts by weight Foaming urethane stock solution of Examples 1 to 4 and isocyanate An example of the specific gravity and thermal conductivity of a urethane foam obtained by mixing a stock solution with various known additives is as follows.

Effect The foamable polyurethane stock solution produced from the production apparatus of the present invention has no danger of destruction of the atmospheric ozone layer, and can be applied to urethane by applying the same simple production apparatus and operation as in the case of using a liquid foaming agent at room temperature. A foam can be manufactured, and the use of such an undiluted solution can attain at once the objects such as preservation of the air environment, urethane foam manufacturing equipment, simplification of operation, and improvement of the working environment for foam manufacturing.

Further, in the present invention, since the adsorption operation is performed in the upper part of the column and the mixing operation is performed in the lower part, the production of the foaming urethane stock solution can be simply achieved on the apparatus side and the operation side.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a first embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating another embodiment of the present invention. In the figure, (1) is an adsorption mixing column, (2) is an exhaust line,
(3) is a vacuum pump, (4) is a valve, (5) is a pressure tank, (6) is a gas supply line, (7) is a regulator, (8) is a valve, (9) is a powder tank, (10) ) Is a powder supply line, (11) is a powder valve, (12) is a liquid tank, (13) is a measuring pump, (14) is a liquid supply line,
(15) is a metering pump, (16) is a discharge line, and (17) is a valve.

Claims (1)

(57) [Claims] 1. A supply section for a foaming gas which is a gas at ordinary temperature, a supply section for silica gel particles, a supply section for a polyol stock solution, and an adsorption / mixing tower receiving supply of foaming gas, silica gel particles and a polyol stock solution from each of the above-mentioned supply sections. The adsorption / mixing tower is provided with an adsorption zone at the top where the silica gel particles come into contact with and adsorb the foaming gas while falling in the tower, and a mixing zone at the bottom where the gas adsorbing silica gel particles for foaming and the polyol stock solution are mixed at the bottom. An apparatus for producing a foamable urethane undiluted solution.