JPH0145422B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous molding device for thermosetting resin decorative laminates and a continuous molding method using the device, and particularly relates to a thermosetting resin decorative laminate that has excellent gloss and is free from warping and twisting. The present invention relates to an apparatus and method for continuously forming decorative laminates at high speed.

Conventionally, methods for manufacturing thermosetting resin decorative boards such as melamine resin decorative boards, diallyl phthalate resin decorative boards, and unsaturated polyester resin decorative boards include:
There are mainly three methods:

The first method is a batch molding method that uses a press machine with one or several stages of flat sheets. For example, multiple sheets of thermosetting resin-impregnated paper and mirror-finished sheets are stacked and inserted into a multistage press machine, and pressure is applied. A method of obtaining thermosetting resin decorative boards of sizes such as 910 mm x 1818 mm (3 shaku x 6 shaku), 1212 mm x 2424 mm (4 shaku x 8 shaku), etc. by heating, cooling under pressure, and then decompressing. It is generally called the hot cold press batch method. The second method is a batch molding method using the same multistage press as the former, but the cooling step under pressure is omitted. For example, one mirror plate made of stainless steel or duralumin, etc.
It is fixed in advance on the heating platen of each stage of a press machine consisting of a stage or several stages, and after heating it and reaching a predetermined temperature, a thermosetting resin-impregnated paper is inserted under the mirror plate, and after press molding, it is kept in a hot state. This method of obtaining a thermosetting resin decorative board is generally called the hot press batch method. The third method is a continuous molding method using a steel belt or roll, for example, thermosetting resin-impregnated paper is continuously inserted into a steel belt press machine that has been heated to a predetermined temperature, and then heated and pressed. This method is called the hot hot press continuous method, in which the thermosetting resin decorative board is obtained by cooling it with a cooling roll or the like after it comes out of the press in a hot state.

Each of the above-mentioned conventional methods has advantages and disadvantages, and it is impossible to say which method is the best method. That is, the first method can provide a thermosetting resin decorative board that has an excellent glossy surface and is free from warping and twisting, but this method has low productivity because it is produced in batches. This method is currently the most commonly used manufacturing method in thermosetting resin decorative laminate manufacturing plants, and while the pressing process requires a lot of time, the same heating plate is repeatedly heated and cooled, which requires a lot of energy. The problem is that the cost is high. The second method has lower energy costs than the first method because the press only heats and does not cool it, but it is not as good as the first method because it takes out the thermosetting resin decorative laminate in a hot state without being cooled under pressure. It is not possible to obtain a thermosetting resin decorative board with a glossy surface. Also, warping,
If you want to obtain a thermosetting resin decorative board without twisting,
The thermosetting resin used for this is subject to some restrictions. That is, it is necessary to use some method such as limiting the resin to a specific one or modifying it to particularly increase flexibility or reduce dimensional changes. This conventional method is currently widely used for integrating melamine resin-impregnated paper with particle board or diallylphthalate resin-impregnated paper and plywood. These have the disadvantage that they cannot produce products with excellent gloss, and when warping or twisting occurs, they are corrected by sprinkling with water or by pasting a balant sheet on the back side. The third method is a method in which the batch production of the second method is made into continuous production by using a steel belt or roll that can be heated and pressurized, and the productivity is higher than the batch production, but like the second method,
It is not possible to obtain a thermosetting resin decorative board with an excellent glossy surface.

Furthermore, since the first and second methods are produced in batches, the size of the thermosetting resin decorative laminate obtained is limited by the size of the press, and in particular, it is not possible to obtain a desired size in the length direction. However, this third method has the advantage that the size in the length direction is arbitrary since it is continuous production.

The present invention takes advantage of these advantages while further improving the above-mentioned drawbacks, and provides a manufacturing method for rapidly producing thermosetting resin decorative laminates with excellent gloss and without warping or twisting using a continuous molding method. It is.

The present invention will be explained in detail below.

There are two conditions for the surface of a thermosetting resin decorative board to have excellent gloss. One of these is that the surface of the mirror plate used is chrome-plated and then mirror-finished, giving it an excellent gloss. In other cases, the molding method is heating and cooling under pressure. When molded by heating alone, an excellent glossy surface cannot be obtained. The reason for this is that gas is generated when the thermosetting resin of the thermosetting resin-impregnated paper is cured during heating and pressure molding.

The gases generated include water generated during condensation polymerization of the thermosetting resin, formalin, moisture contained in the impregnated paper, and solvents.

In other words, in the hot hot press method, the pressure is released in a heated state, that is, in a state where gas is generated, and this gas is present between the mirror plate and the surface of the thermosetting resin decorative board and clouds the mirror plate. It is not possible to obtain a thermosetting resin decorative board with excellent gloss as obtained by the batch method.

Therefore, as a result of intensive research, the present inventors have decided to connect two conventional continuous molding press machines with steel belts, and use each one exclusively for heating and pressing, and the other for cooling and pressing. By installing not only a heating device but also a new cooling device on the continuous molding press machine, we have completed the hot hot press continuous method, which has an excellent gloss that can be obtained with the conventional hot cold press batch method. We were able to obtain high-quality thermosetting resin decorative laminates without warping or twisting at high speed.

Embodiments of the present invention will be described below based on the drawings. First, FIG. 1 is a schematic diagram of a conventional continuous molding method. In this drawing, thermosetting resin decorative board 1
1 is a mirror surface on the surface side of the decorative board which is inserted into a continuous molding press 3 while overlapping a thermosetting resin pattern impregnated paper 1 and a thermosetting resin core impregnated paper 2 and heated by a heating drum 6 and a heating plate 7. It is obtained by heating and press-forming between the steel belt 4 and the back side 5 of the decorative board and then cooling it in a cooling section 9 equipped with a cooling roll 10.

The steel belt 4 on the front side and the steel belt 5 on the back side are heated by heat transfer from a heating drum 6 and a heating plate 7. The heating drum 6 also functions as a feed roll for the steel belt, but whether or not all four drums can be heated depends on the temperature of the steel belt used. Usually, the four drums 6 are the main sources of heating, and the heating plate 7 inside is used for auxiliary heating to keep the steel belt from getting cold. The temperature of the steel belt depends on the type of thermosetting resin used and the production speed, that is, the time during which the steel belt is heated and pressurized. For example, the temperature is generally 150 to 160°C for melamine resin, and 120 to 130°C for diallyl phthalate resin. When the steel belt has these temperatures, the temperature of the heating drum, which is the heat source, is about 20 to 30 degrees Celsius higher than the temperature of the steel belt. Thermo oil is generally used as the heat source for the heating drum.

Next, the pressurization method is as follows:
Pressure is applied from both sides of the steel belt 5 on the back side. The pressurizing method is based on one heating drum 6a.
This is performed using the tension of the other heating drum 6b and the air pressure of the high-pressure air plate 8.
High-pressure air of 20 to 30 kg/cm ² generated by a high-pressure compressor is introduced into the high-pressure air plate 8 to pressurize the steel belt. This pressure varies depending on the properties of the thermosetting resin used, the amount of resin, the base material, etc. For example, in the case of melamine resin decorative board, it is around 20Kg/ ^cm2 , and in the case of diallylphthalate resin decorative board, it is around 20Kg/cm2.
It is carried out at around 10Kg/ ^cm2 .

As a result of examining the surface gloss, warping, twisting, etc. of the thermosetting resin decorative board obtained by such a manufacturing method, it was found that the surface gloss is not bright enough even if the mirror-finished steel belt has a chrome-plated mirror finish. There is uneven gloss in some areas and the excellent gloss that can be obtained with the hot cold press batch method cannot be obtained. Warping and twisting are undesirable, depending on the type and amount of thermosetting resin used, the structure of the decorative board, molding time, molding temperature, etc. That is, the thermosetting resin decorative board obtained by this manufacturing method is limited in terms of the thermosetting resin used, the structure, etc. In addition, the surface has a matte finish, and the thermosetting resin decorative board that has excellent gloss and is free from warping and twisting, which is the object of the present invention, cannot be obtained. Furthermore, if the continuous molding machine is operated at high speed, rapid peeling between the layers of the thermosetting resin decorative laminate, that is, punctures will occur, so there is a limit to the operating speed.

Next, FIGS. 2 and 8 are longitudinal sectional views of a continuous molding press for this method. First, a continuous molding method in which two continuous molding presses each having a steel belt are connected as shown in FIG. 2 will be explained. The continuous molding press 3A on the inlet side A into which the thermosetting resin-impregnated paper is inserted is for heating and pressing, and the continuous molding press 3B on the exit side B is for cooling and pressing. The continuous molding press machine 3A for heating and pressing is the same as that shown in FIG. The continuous molding press machine 3B for cooling and pressing has a cooling drum 12.
a, 12b, a mirror-finished steel belt 4b on the front side, a steel belt 5b on the back side, and a high-pressure air plate 8. A continuous molding press machine 3A for heating and pressing.
The thermosetting resin decorative board heated and pressurized is continuously carried into a continuous molding press machine 3B for cooling and pressurizing.
It comes out of the press completely cooled. Since the connection distance C between the two units is in a pressureless state, it affects the gloss, quality, etc. of the thermosetting resin decorative board obtained. Therefore, it is preferable to keep it as short as possible. Further, it is preferable that the material, gloss, etc. of the mirror-finished steel belts on the front side of the two continuous molding presses be the same. In order to obtain a surface with particularly excellent gloss, it is necessary to use a chrome-plated mirror finish for heating and pressing, and the same chrome-plated mirror finish for cooling and pressing.

Next, a continuous forming press machine in which the steel belt has a temperature distribution from a high temperature to a low temperature as shown in FIG. 3 will be explained. The temperature of the steel belt on the entrance side A, where the thermosetting resin-impregnated paper is inserted, is high, and the temperature of the steel belt on the exit side B, where it is heated and pressure-molded and exits as a thermosetting resin decorative board, is lowered, so that the paper is thermoset. The plastic decorative board is cooled under pressure and comes out. This method is a further improvement of the method shown in FIG. 2, in which heating and cooling are performed using one continuous molding press. There are various methods for changing the temperature distribution of a steel belt from high to low, but two of the main methods will be explained. First, as shown in FIG. 3, the first method is to use heating drums 6a and 6b as heating sources and a cooling plate 7a as a cooling source. When the upper and lower steel belts 4 and 5 are driven in this manner, the temperature distribution of the upper and lower steel belts 4 and 5 from the inlet side A to the outlet side B gradually and continuously changes from high temperature to low temperature. That is, the upper and lower steel belts 4 and 5 are heated by the heating drum 6a on the inlet side.
begins to be cooled on the cooling plate 7a, and further cools down as it moves. The steel belt exiting the outlet is heated again by the heating drum 6b. This heating drum 6b serves as auxiliary heating for the heating drum 6a on the inlet side. In this state, the upper and lower steel belts 4,
5 is driven and rotates, the temperature of the upper and lower steel belts 4 and 5 is highest on the inlet side A and lowest on the outlet side.

The second method is a method in which the cooling plate 7a of the first method is divided into a heating plate and a cooling plate, with the inlet side A serving as the heating plate and the outlet side 6 serving as the cooling plate. In this case, one heating drum on the inlet side A is sufficient.

FIG. 4 shows the temperature distribution of the upper and lower steel belts 4 and 5 obtained by such a method and the surface temperature of the thermosetting resin decorative board to be manufactured. The horizontal axis shows the pressurization time from the inlet side A to the outlet side B of the continuous molding press machine, and the vertical axis shows the temperature of the upper and lower steel belts 4 and 5 and the surface of the thermosetting resin decorative board obtained by pressurization. When the temperature is measured, a curve as shown in Fig. 4 is obtained. That is, from the time the thermosetting resin-impregnated paper is inserted, it begins to receive heat from the steel belt, and as it is pressurized and moved, the heat increases and the thermosetting resin hardens. Then, the thermosetting resin receives the heat necessary for curing and enters cooling, where it is gradually cooled and depressurized. The inlet temperature and outlet temperature should be determined depending on the type and properties of the thermosetting resin used, but when manufacturing melamine resin decorative boards, the inlet side should be 120 to 160℃ and the outlet side should be 120 to 160℃.
20-60°C is common.

The surface temperature of the thermosetting resin decorative board manufactured in this way is determined as shown in Figure 4, when the hot platen of the press was heated and cooled under pressure in the conventional hot cold press batch method. As a result, it was possible to continuously obtain a thermosetting resin decorative board having excellent luster and being free from warping and twisting, which is the objective of the present invention.

Here, the method of bringing the steel belt from a high temperature to a low temperature is not particularly limited, and any method may be used as long as it repeats heating and cooling in a short period of time.

As a side effect of the present invention, it is possible to prevent punctures that often occur in hot-hot pressing, which is performed only by heating because heating and cooling are performed under pressure. Here, puncture refers to the condensation water generated when the resin in a thermosetting resin decorative board is cured by heating, as described above, and the water and solvent contained in formalin or impregnated paper becoming gaseous and expanding. This refers to the so-called punctured state in which the pipe swells to release the pressure and take it out. This puncture is more common when the cure is still uncured, ie, when excessive gas is still being generated. Therefore, when attempting to obtain a thermosetting resin decorative laminate using a continuous molding press machine at high speed, the above-mentioned puncture becomes a serious problem and a high yield cannot be achieved. Therefore, this method of pressurizing and cooling followed by depressurization is very effective for this purpose.

As described above, the hot cold press continuous method of the present invention has a gloss that cannot be obtained with conventional continuous molding press machines, and can continuously obtain thermosetting resin decorative laminates at high speed that are free from warping, twisting, and punctures. It is something that can be done.

Up to now, only the thermosetting resin decorative board in which thermosetting resin impregnated paper is laminated has been described, but the thermosetting resin decorative board of the present invention has a surface layer of thermosetting resin impregnated paper and a lower layer of thermosetting resin impregnated paper. Of course, it can also be applied to base materials such as plywood, particle board, asbestos calcium silicate board, etc.

Next, embodiments of the present invention will be described.

Example 1 Overlay paper with a basis weight of 25g/ ^m2 and paper with a basis weight of 80g/m2
Each ^m2 of pattern paper was impregnated with melamine resin, and after drying, it was rolled up to obtain a long roll of overlay impregnated paper and pattern impregnated paper. Next, the basis weight is 190g/m ²
After impregnating the kraft paper with phenolic resin and drying it,
A long roll of core-impregnated paper was obtained.

These impregnated papers were unwound at a feed speed of 7 m/min so that the pattern impregnated paper and the overlay impregnated paper could be sequentially stacked on top of the three core impregnated papers, and a steel belt with a mirror finish on the surface was used. Insert into a continuous molding press machine for heating,
After heating and pressure molding at 150℃ and 15Kg/ ^cm2 for 30 seconds,
15Kg/cm ² immediately in a cooling continuous forming press with identical mirror-finished steel belts.
A melamine resin decorative board with a surface temperature of 20°C was obtained by cooling for 10 seconds under pressure. This decorative board has a thickness of 1.0
mm, the surface had excellent gloss and was free from warping and twisting.

Example 2 A pattern paper having a basis weight of 120 g/m ² was impregnated with diallyl phthalate resin, and after drying, the paper was wound to obtain a long roll of pattern-impregnated paper. Next, continuously put 4mm plywood under the pattern-impregnated paper, and
The unwound pattern-impregnated paper is placed on top of the plywood and inserted into a heating continuous forming press having a steel belt with a mirror-finished surface.
After heating and pressure molding at 120℃ and 10Kg/ ^cm2 for 20 seconds,
10Kg/cm ² immediately in a cooling continuous forming press with identical mirror-finished steel belts.
The mixture was cooled for 10 seconds under pressure of 20°C to obtain diallyl phthalate resin decorative plywood with a surface of 20°C. The surface of this decorative plywood had excellent gloss and was free from warping and twisting.

Example 3 Pattern paper with a basis weight of 80g/ ^m2 and a patterned paper with a basis weight of 100g/m2
Each m ² of kraft paper was impregnated with melamine resin, and after drying, it was rolled up to obtain a long roll of pattern-impregnated paper and Patskar-impregnated paper. Next, while unwinding both impregnated papers so that the pattern impregnated paper is on the front side of the 20 mm particle board and the backer impregnated paper is on the back side, the particle board is continuously introduced, and the same continuous molding as in Example 1 is carried out. A melamine decorative particle board was obtained by heating and cooling using a method. The surface of this decorative particle board had an extremely high gloss.

Example 4 In the method of Example 1, instead of the two continuous molding presses of Example 1, a continuous molding press machine in which the steel belt had a temperature distribution from high temperature to low temperature was used.

The temperature of the steel belt on the inlet side is 150℃,
The temperature of the steel belt on the exit side was 70°C.
Using a mirror-finished steel belt with such a temperature distribution, we produced a melamine resin makeup with an extremely high gloss and no warping or twisting, using a press pressure of 15 kg/cm ² and a press time of 50 seconds. The board is ready.

As described above, according to the present invention, a glossy, warp-free thermosetting resin decorative board can be obtained continuously and at high speed, which has not been possible with conventional apparatuses and methods.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional continuous molding method for a thermosetting resin decorative board. In this drawing, 1 is paper impregnated with a thermosetting resin pattern, 2 is paper impregnated with a thermosetting resin core, 3 is a continuous molding press, 4 is a mirror-finished steel belt on the front side of the decorative board, and 5 is a steel belt on the back side. , 6 is a heating drum, 7 is a heating plate, 8 is a high-pressure air plate for pressurization, 9 is a cooling section, 10 is a cooling roll, and 11 is the obtained thermosetting resin decorative board. FIGS. 2 and 3 are longitudinal sectional views of the continuous molding press of the present invention. A is the inlet side where materials such as thermosetting resin-impregnated paper are inserted, B is the outlet side, 3A is a continuous molding press machine for heating and pressing, 3B is a continuous molding press machine for cooling and pressing, 12a and 12b are cooling Drum, 4b is a cooling mirror steel belt on the front side, 5
b is a cooling steel belt on the back side, 6a and 6b are heating drums, and 7a is a cooling plate. FIG. 4 is a graph showing the surface temperature of the steel belts 4 and 5 and the surface temperature of the decorative board manufactured by the method of FIG. 3.

Claims (1)

[Claims] 1. A continuous molding press machine for heating and pressing having a mirror-finished steel belt with a heating drum and a heating plate as heating sources, and a steel belt tension and a high-pressure air plate as a pressure source, and a cooling drum as a cooling source. This is a continuous molding device for thermosetting resin decorative laminates, which is connected to a continuous molding press for cooling and pressing, which has a mirror-finished steel belt and uses the tension of a steel belt and a high-pressure air plate as a pressure source. 2. When continuously molding a thermosetting resin decorative board, two continuous molding presses each having a steel belt are connected, one for heating and pressing, and the other for cooling and pressing. Continuous molding method for thermosetting resin decorative laminates. 3. A continuous molding device for thermosetting resin decorative laminates, which is equipped with both a heating drum and a cooling plate so that the surface temperature of the steel belt gradually changes from high to low. 4. When continuously molding a thermosetting resin decorative board, a heat treatment method characterized by using a continuous molding press machine in which the temperature distribution of the steel belt is gradually changed from high to low, and the temperature distribution is continuously changed. Continuous molding method for curable resin decorative laminates.