JPS6128495B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for producing a synthetic resin foam without using a channel-shaped release paper, and without slicing the obtained foam or performing any other post-processing. This invention relates to a method for producing a foam that can be used as a final product as it is.

Conventionally, to manufacture polyurethane foam and other foams, a continuous container made of kraft paper coated with synthetic resin, wax, etc. on the inside, or thin synthetic resin sheets bent into a groove shape is placed on a conveyor that moves at a constant speed. The synthetic resin foaming stock solution is discharged from the nozzle into the groove-shaped container, and is heated to foam in the groove-shaped container, thereby producing continuous production. There is. The large slab thus created is then peeled off and removed from the release paper on the bottom and sides used for molding, cut into lengths of 1 to 2 meters, and stored for about 24 hours to complete the process. The skin is then cured, the epidermis and other defective parts are removed, and the slices are sliced to a predetermined thickness to be used as pine tresses and other cushions.

However, a number of problems have been pointed out in the conventional methods for producing foams. In other words, in the past, in addition to using a large amount of release paper, a large slab was created and then subjected to slicing and other cutting processes, which resulted in high post-processing costs and the production of a large amount of defective material. Because the size of the slab is large, for example, 2000mm wide x 900mm high x 2000mm long, internal heat generation of 150 to 170°C occurs during curing after the foaming reaction, and this continues for several hours, causing a fire. Due to such high internal heat generation, in addition to other dangers,
For example, in the case of polyurethane foam, significant yellowing occurs, which extremely reduces the commercial value of the product obtained. In order to avoid this, various researches have been carried out to obtain foams with the final thickness without the need for post-processing such as slicing. When removing the release paper constructed in There are various problems such as the feel is completely different from normal properties, and the cross-sectional shape of the foam is sloping, making it impossible to obtain a square cross-section. However, as in the past, grooved release paper is used to create a continuous large slab, which is then cut into large pieces, cured completely, and then sliced to produce the final product. This invention solves all of these conventional drawbacks at once, and without using any grooved release paper, the foam obtained by discharging the foaming stock solution and completing the foaming reaction can be used as a final product as it is. This is an attempt to obtain a method for producing a synthetic resin foam that can be produced without using a channel-shaped release paper. A concave conveyor is formed without being surrounded by a side belt that moves in synchronization with the belt, and the creamy foaming initial stock solution is continuously injected into one end of the conveyor, and the foaming initial stock solution is poured from the joint between the bottom conveyor belt and the side belt. In addition to allowing the foaming reaction to occur while preventing liquid leakage, the upper surface of the foam is pressed by a conveyor from the point where the foaming gas finishes exiting from the surface of the foam and the bubble generation reaction ends to the point where the crosslinking reaction ends. It is characterized in that it is lightly compressed to form a foam with the thickness of the final product. The details of this invention will be explained below based on an illustrated embodiment. In the figure, reference numeral 1 denotes a conveyor, on which an endless belt of Teflon sheets, stainless steel plates, and other releasable members is stretched. Reinforcement plates 2 ₁ and 2 ₂ are upright on both ends of the upper surface of this conveyor 1.
Inside each of them, side bands 3 ₁ , 3 ₂ are separate from the bottom conveyor and made of paper or the like coated with a release agent.
is supplied from a winder roll (not shown) in synchronization with the speed of the conveyor, so that a concave conveyor consisting of a bottom conveyor and side bands is formed without using a grooved release paper. Incidentally, this side band may be constituted by an upright endless belt conveyor. Reference numeral 4 denotes a foaming stock solution supply nozzle, through which a mixed solution of, for example, a polyol/tolylene diisocyanate amine catalyst is stirred in a mixing head and then continuously supplied. Leave as a creamy foaming initial stock solution. That is, by using the high viscosity, cream-like foaming initial stock solution as the discharged stock solution as described above, the channel-shaped container as the foaming device can be made into a channel-shaped container made by folding a piece of release paper into a U-shape. At least as a result of experiments, it has been confirmed that simply placing the side bands 3 ₁ and 3 ₂ on both sides of the upper surface of the conveyor 1 can prevent liquid leakage from the joints. In order to make the discharged foaming stock solution into a cream-like foaming initial stock solution, it can be easily adjusted by, for example, increasing the amount of catalyst or extending the nozzle length. In addition, in order for the obtained foam to have the same thickness as the final product, the discharge amount of the foaming stock solution must be adjusted in advance to a predetermined amount corresponding to the thickness of the final product. 5 is a pressure conveyor that lightly compresses the upper surface of the foam from the point where the foaming gas finishes exiting from the surface of the foam and the bubble generation reaction ends to the point where the crosslinking reaction ends; With this in mind, use Teflon, stainless steel plates, and other releasable materials. This pressing conveyor 5 is required to lightly compress the foam from the point where the foaming gas of the foam has finished coming out from the surface of the foam and the bubble generation reaction has ended, and presses the upper surface of the foam from before that point. In this case, the foaming reaction itself may be suppressed, leading to bubble bursting and other bubble roughness. In addition, the pressure on the foam should be limited to light compression, and if the pressure is applied more than necessary, uniform foam formation cannot be expected.Furthermore, the pressure conveyor is spaced apart from the conveyor 1 according to the thickness of the product. Its length is also
Since it is necessary to lightly compress the upper surface of the foam until the crosslinking reaction is completed, the curing time may vary depending on the thickness of the resulting foam and cannot be set uniformly; however, as an example, we will use the method of manufacturing Mattress. A length of approximately 10 meters is sufficient. It goes without saying that the pressing conveyor 5 is moved in the same direction in synchronization with the conveyor 1 that forms the bottom of the channel conveyor. Furthermore, if a transfer roll is used for the pressure conveyor 5 and the conveyor 1 that constitutes the concave part, and a release agent is applied to the surface, the mold release from the obtained foam will always be performed smoothly. figure,
The surface properties of the foam can be further improved.

As described above, according to the present invention, it is possible to eliminate the need to use a large amount of grooved release paper by using a high viscosity foaming initial stock solution instead of using a liquid foaming stock solution as in the conventional production of foams. This not only reduces costs and improves problems such as the treatment of used release paper, but also eliminates the drawbacks of the past, such as roughening of the surface of the foam when peeling the release paper from the resulting foam. were all resolved. Furthermore, according to the present invention, the discharged foaming stock solution is lightly compressed between the releasable conveyors arranged at a distance from each other in terms of the thickness of the final product, and a foaming reaction is carried out to produce the foam. The resulting foam naturally has a rectangular cross section, and its surface properties are highly flexible, and even when compared with the virgin cutting surface cut from a conventional slab, the properties are equal to or better than this. Of course, since the foaming reaction and the queue are completed in succession, there is no internal heat generation or any risk of fire resulting from this.
Therefore, even in the case of polyureta foam, yellowing can be largely avoided. Of course, there is no slicing process, and the resulting foam can be used immediately as it is, making it possible to significantly reduce manufacturing costs.

Example Using the apparatus shown in the figure, polyureta foam was continuously manufactured using the following formulation. However, the width of the conveyor is 200mm, and the width between both sides of the conveyor is 1500mm.
mm, conveyor speed 8m/min, nozzle length 1m, interval between bottom conveyor and pressure conveyor 100mm, bottom conveyor and side belt are separate, leaving a small gap between them, and both bottom conveyor and pressure conveyor are coated with silicone on top of Teflon coating. A material coated with a mold release agent was used.

Compounding formula CP-3000 (glycerin base trifunctional molecular weight
3000 Polyether polyol 100 parts by weight Water 4.0 Triethylenediamine 0.2 Silicone oil 1.5 Tin catalyst (dibutyl dilaurate) 0.25 Freon 11 5.0 Tolylene diisocyanate (T-80) 53.0 The resulting product is the initial stage of foaming discharged from the nozzle. There was no trace of the stock solution leaking from the gap between the bottom conveyor and the side band, and a foam with a square cross section with clean corners was obtained.

[Brief explanation of the drawing]

The figure is a perspective view of an apparatus according to an embodiment of the method of this invention. 1...Conveyor, 3 ₁ , 3 ₂ ...Side band, 4...
Nozzle, 5...press conveyor.

Claims (1)

[Claims] 1 A concave conveyor surrounded by a bottom conveyor belt made of a releasable member without using a grooved release paper, and side bands on both sides of the upper surface that are separate from the conveyor belt and move in synchronization with the conveyor belt. A cream-like foaming initial stock solution is continuously injected into one end of the foaming reactor while preventing leakage of the foaming initial stock solution from the bottom conveyor belt, side band, and seam, and a foaming reaction is carried out. The upper surface of the foam is lightly compressed using a pressure conveyor from the point where the bubble generation reaction ends after exiting the surface to the point where the crosslinking reaction ends to form a foam having the thickness of the final product. Method for producing synthetic resin foam.