JPS6015451B2 - Manufacturing method of plate-shaped foam material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a rigid or semi-rigid urethane resin plate-shaped foam material suitable for construction, construction, containers, etc.

Urethane resin foams are produced, as is well known, by adding a blowing agent and an activator mixture to polyester or polyether and isocyanate, and foaming the mixture by leaving the mixture at room temperature or by heating if necessary.

In this case, the elongated plate-shaped foam material is formed by a pair of endless mold members arranged vertically facing each other, and is moved in a mold that moves in one direction to complete foaming and form it into a predetermined shape. The pair of mold members that also serve as a caterpillar-type pulling device are divided into a number of mold pieces in the width direction, so both mold members are designed to move at the same speed. However, due to slight structural differences, expansion and contraction due to thermal changes, etc., there may be differences or unevenness in the moving speed.
As a result, the size and shape of the foam removed from the mold may be uneven or the surface may be scratched, or the surface of the foam or the protective layer covering the surface may be damaged by the foaming pressure at the joints of the mold pieces. It has the disadvantage of creating irregular protrusions on the biting surface, which impairs commercial value. In addition, if an endless band of metal with a smooth surface is used instead of a mold member consisting of a large number of divided mold pieces, the problem of creating irregular protrusions on the surface will be eliminated since it is seamless, but the problem of creating irregular ridges on the surface will be eliminated. This may cause slippage between the surface of the rigid or semi-rigid foam and the endless band, which may damage the surface of the foam or cause cracks inside. Moving the endless band greatly reduces efficiency. The present invention eliminates these drawbacks and makes it possible to continuously produce defect-free plate-shaped foam materials at high speed.

That is, in order to achieve this object, the present invention overlaps a wet, wet-containing protective layer with an endless metal band with a smooth surface, and while moving them in one direction, reacts and foams the protective layer in contact with the protective layer. , is characterized in that at least one surface is coated with this protective layer. With such a structure, a thin soft synthetic resin layer with open cells is formed in the portion in contact with the protective layer, and this absorbs slippage, thereby eliminating the above-mentioned drawbacks.

An embodiment of the present invention will be described below with reference to the drawings. Two substantially seamless endless bands 1 and 2 made of metal such as steel and having a suitable width and having smooth surfaces are vertically opposed to each other. They are arranged and wrapped around the front and rear guides 3 and 5 and the drive shafts 4 and 6 driven by a prime mover (not shown), and are oriented at intervals narrower than the maximum foaming height of the urethane resin raw material, which is supplied in predetermined amounts and left to naturally stand. An auxiliary guide theory 8 that forms a mold 7 that moves in one direction when the mold 7 is formed, and prevents the upper and lower endless bands 1 and 2 from sagging at the location where the mold 7 is formed.
・・・・・・・・・・・・・、9・・・・・・・・・・・・・
Temperature control device 10 consisting of a duct which brings into contact an appropriate number of
, 11 will be installed.

The lower endless band 2 extends backward from the rear end of the upper endless band 1 in the direction of movement of the mold 7, and above it, raw materials for making a rigid or semi-rigid foam 21 of urethane resin are separately stored. A mixer 14 is installed in which the pig material tanks 12 and 13 are connected together, and a cassette 15 containing aggregates to be added as desired is installed.
16 and 17 are connected to the mixer 14 or installed before and after it.

This bottom endless strip 2 is made of fire-resistant, noncombustible and hard board material such as metal plate, gypsum board, wood wool cement board, asbestos slate board, etc.
2 is placed thereon, and as the endless band 2 moves, it is sent toward the mold 7, and the liquid raw material for making the urethane resin foam 21 mixed in the mixer 14 is dropped and supplied to the upper surface of the mold 7, and if necessary, this Aggregate is dropped and distributed together with the raw materials or before and after the raw materials. The mixed raw materials pass through a creamy unreacted period, enter a gelling period, and foaming is carried out in earnest, and enter the mold 7 in a state where the foaming is not completed and is fluid. At the entrance of the mold 7, the protective layer 23 is taken out from the winding frame 18 and fed along the upper endless belt 1, and is applied to the upper and lower endless belts 1, 2 and the left and right endless belts (not shown) or the endless belts 1, 2. Foaming was completed in a state where the green was surrounded on all four sides by shielding walls protruding from either side of the machine edge, one surface was covered with the plate member 22, and the opposite surface was covered with the protective layer 23. A plate-shaped foam body made of a hard or semi-hard urethane resin foam 21 is taken out from the mold 7.

This plate-like foam is made to have a long length equal to the thickness and width of the mold 7, and the foam 21 is a closed cell. Protective layer 23
Papers that have water absorption properties and absorb moisture from the atmosphere and remain moist, such as kraft paper, or those that contain water, or those that contain crystalline water in their composition, such as asbestos paper and gypsum paper. and has maneuverability. Further, on the opposite side of the surface of the protective layer 23 that is in contact with the outer foam 21, there is a coating 24, such as aluminum foil or synthetic resin film, which has good peelability from the metal endless strip and has waterproof properties.
may be layered. This protective layer 23 overlaps the upper endless band 1 in the mold 7 and moves almost integrally with it, releasing moisture contained in the urethane resin foam 21 by heat when it is generated, and comes into contact with the protective layer 23. The urethane bond is replaced with a urea bond in that part to form a thin open-cell soft synthetic resin layer 25. It is preferable that this fin-like synthetic resin layer 25 be formed as thin as possible without significantly reducing the mechanical tension and surface hardness of the plate-shaped foam material.
Even if slippage occurs between the protective layer 23 and the foam body 21, it acts as a buffer material that absorbs the slippage, thereby preventing damage to the surfaces of the protective layer 23 and the foam body 21 or causing cracks inside the foam body 21. Here, the foam 21 and the soft synthetic resin layer 25
For example, when water is used as the blowing agent, the isocyanate and the water The carbon dioxide generated by the reaction with foam creates bubbles, and when Freon is used as a blowing agent, the heat of reaction with the urethane polymer vaporizes Freon, an inert, low-boiling solvent, to create bubbles. Then, depending on the viscosity and solidification time of the raw materials for the urethane resin, the size of the bubbles, the vapor pressure, etc., the cell membrane is maintained or broken to become closed cells, open cells, or partially open cells.

When Freon is used, a closed-cell or partially open-cell, and thus rigid to semi-rigid, foam 21 is created because Freon gas has a relatively low diffusion rate. Furthermore, the reaction between isocyanate and water is better than the reaction between isocyanate and polyester or polyether, which is a raw material for urethane resin, and therefore, the reaction between isocyanate and water is better in the area in contact with the protective layer 23 containing water. Through the reaction, carbon dioxide is generated and urea bonds are formed in place of urethane bonds, and the reaction system is disturbed by the urea bonds, creating an open-celled and therefore flexible soft synthetic resin layer 25. That's what happens.

FIG. 3 is a cross-sectional view of a plate-shaped foam manufactured according to a different embodiment of the present invention, in which a protective layer 23 with a coating 24 laminated on the lower surface is placed on the lower endless band 2 and directed toward the mold 7. A liquid raw material of urethane resin is supplied to the upper surface of the mold, and if necessary, aggregate is supplied together with this raw material or before and after the raw material. supplying a layer 23 along the upper mineral band 1;
It was manufactured by completing foaming in mold 7.

In this case as well, thin open-cell synthetic resin layers 25, 25 are formed on both upper and lower surfaces of the closed-cell rigid or semi-rigid foam 21 due to the above-mentioned formation reasons. still,
The aggregate to be added and mixed into the foam 21 as necessary is for the purpose of pyrolysis, and is made of acid, citric acid, or a metal salt thereof.
Inorganic substances, calcium carbonate, alumina, etc. that have the property of foaming and expanding at a temperature below the heat resistance temperature of urethane resin such as shelf sand, etc.
Inorganic substances that do not have foaming expansion properties such as silica and cinnabar sand, inorganic short fibers such as glass fibers and asbestos, inorganic foam particles such as pearlite grains and cellular glass, and one or two known scale combustion agents. The above are used.

In addition, in the present invention, when one surface of the foam is covered with the longest hard slope member, the part of the mold that the slope member contacts may be constituted by a mold member formed of a large number of mold pieces; An endless band of metal may be superimposed on such a mold member and brought into contact with the protective layer.

As described above, in molding a rigid or semi-rigid plate-shaped foam material made of urethane resin that is lightweight and has high mechanical strength, the present invention combines a moisture-containing flexible protective layer with an inorganic band of metal with a smooth surface. Since the urethane resin is reacted and foamed while stacking and moving these layers, a thin open-cell European synthetic resin layer is formed in the area in contact with the protective layer due to the above-mentioned formation reason, and this layer is interposed. In this way, a plate-shaped foam material in which the foam body and the protective layer are integrally laminated is continuously manufactured. Since the endless metal strip has virtually no seams, it does not have the disadvantage of creating irregular protrusions on the surface, and it also avoids the possibility of slipping between the endless strip and the protective layer when the endless strip is moved at high speed. Even if there is a problem, the abrasive synthetic resin layer acts as a buffer and absorbs the slippage, allowing high-quality plate-shaped foamed materials to be manufactured with high efficiency without damaging the surface or causing internal cracks.

[Brief explanation of drawings]

Fig. 1 is a schematic front view showing an embodiment of the present invention, Fig. 2 is a partial vertical cross-sectional view of a plate-shaped foam obtained by the present invention, and Fig. 3 is a schematic front view showing an embodiment of the present invention. FIG. 2 is a partial vertical cross-sectional view of a plate-shaped foam material. 1, 2... Inorganic band, 7... Mold, 21... Foam, 22.
... Slope member, 23 ... Protective layer, 25 ...
...Soft synthetic resin layer. Figure 1 Heron Figure 2

Claims (1)

[Claims] 1. When reacting and foaming raw materials for urethane resin to form a rigid or semi-rigid plate-like foam, a flexible protective layer containing moisture is layered with an endless metal band with a smooth surface, and these are moved in one direction. 1. A method for producing a plate-shaped foamed material, which comprises performing reaction foaming in contact with a protective layer, and covering at least one surface with the protective layer.