JP2001030280A - Manufacture of melamine resin decorative plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recycle a melamine resin waste liquid by mixing a melamine resin waste liquid in which an emulsifier is added with a powder of a melamine resin decorative plate waste material, heating to dry the mixture, recomminuting the mixture, adding the recomminuted mixture to a phenol resin liquid for a core, and coating phenol resin-impregnated paper with the resin liquid. SOLUTION: In the case of manufacturing a melamine resin decorative plate, an emulsifier is added to a melamine resin waste liquid, the mixture is heated while agitating, suspended, and cured. Then, the cured mixture is mixed with a powder obtained by comminuting a melamine resin decorative plate waste material. After the resultant mixture is heated to be dried, the heated mixture is recomminuted, added to a phenol resin liquid for a core, phenol resin- impregnated paper for the core is coated with the mixture, and the coated paper is used as a core layer. That is, a core sheet 1 is unwound, impregnated with a phenol resin liquid 2, heated to be dried by a drying drum 3 to obtain a phenol resin-impregnated paper. This paper is coated with a phenol resin liquid in which the powder of the decorative plate waste material is added by roll coaters 4 and 5, heated to be dried in a drying drum 6, thereby manufacturing a core layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melamine resin decorative plate which is laminated and integrated using a melamine resin-impregnated paper for a surface decorative layer and a phenol resin-impregnated paper for a core layer. And a method of manufacturing a decorative board for recycling waste melamine resin decorative board.

[0002]

2. Description of the Related Art Melamine resin decorative boards are often used for table tops, sink doors, wash basin surfaces, etc. because of their hard surfaces, heat resistance and excellent design.
In addition, there are many types such as general types, wall types, floor types, and post-form types, and a recent trend has been the production of various types and small quantities.

[0003] Among the resins used for the production of melamine resin decorative boards, phenolic resin liquids have good preservability, so they can sufficiently cope with small-scale production of many kinds, and are used in large quantities.
A small amount is treated as waste liquid. Compared with the phenol resin liquid, the melamine resin liquid has poor preservability, so that although the amount used is small, the amount treated as a waste liquid is large. When melamine resin waste liquid is usually left in a sedimentation separation tank for several days, most of the resin hardens and precipitates, so it can be easily separated from solid and liquid components, and the liquid component is treated by activated sludge method etc. , The solids are incinerated. Recently, there are environmental problems, especially dioxins, and regulations on incineration are becoming stricter. In addition, there is a demand for a recycling method from the viewpoint of resource saving measures.

[0004] On the other hand, when producing decorative boards or cutting, waste materials such as decorative panel scraps, sander powder or cutting powder are discharged. Waste materials discharged during production go through processes such as pulverization and sieving, and are used, for example, as fillers for phenolic resin molding materials. It is preferable because of increased use.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a melamine decorative board by recycling melamine resin waste liquid and melamine resin decorative board waste.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a melamine resin decorative board which is laminated and integrated using a melamine resin impregnated paper for a surface decorative layer and a phenol resin impregnated paper for a core layer. After adding and heating and stirring and stirring while stirring, the melamine resin decorative board waste material was ground and mixed with powder, and then heated and dried.
A method for producing a melamine resin decorative board laminated and integrated by using a material obtained by re-grinding a powder, adding it to a phenol resin liquid for a core, and applying it to one or both surfaces of a phenol resin impregnated paper for a core as a core layer. It is about.

The melamine resin impregnated paper used for the surface decorative layer is produced by the same method as that for a normal melamine resin decorative plate. Decorative paper for the surface, in the kraft paper yelling paper making the pigment, but those from 50g / m ² of 200g / m ² is used, usually often used those of 80g / m ² ~140g / m ² In addition, if necessary, a printed pattern is used on the surface. As a device for impregnating the resin liquid, a device designed for ordinary melamine resin impregnation can be used. For example, it comprises a paper unwinding equipment, a varnish bat for immersing and impregnating paper in a resin liquid, a squeeze roll for adjusting the amount of resin, an impregnating equipment equipped with a handjob bar and a doctor knife, an air support type drying cylinder, a cutting equipment, and the like. There is an impregnation device.

[0008] The melamine resin liquid is basically used by reacting melamine and formaldehyde.
Depending on the application, those modified with urea and those modified with acetoguanamine or benzoguanamine are used. Therefore, the melamine resin waste liquid is a mixture of one or more of these.

Further, the melamine resin liquid has a poor storage stability since the reaction proceeds even at room temperature. When an appropriate amount (e.g., 2 to 6%) of an emulsifier such as polyvinyl alcohol (hereinafter referred to as PVA) is added to the melamine waste liquid and heated with vigorous stirring, the melamine resin is cured and the cured melamine resin covered with an emulsifier film is formed. Fine particles are produced. Curing of the resin in the melamine resin liquid proceeds at room temperature as described above.
It cures quickly when heated to ~ 95 ° C. The obtained resin liquid is stable because the resin component is hardened, and returns to the original emulsified state by stirring even if precipitation occurs. Examples of the emulsifier include PVA, sodium alginate, carboxymethylcellulose, milk casein, gum arabic, and the like, and PVA that is water-soluble, easy to handle, and excellent in dispersibility is preferable. Considering the water resistance of the decorative board, PVA having high saponification degree and good water resistance is preferable. One or more surfactants selected from anionic, cationic and neutral surfactants may be used.

[0010] The molded decorative board is cut into four sides, sanded on the back side, and then subjected to an inspection process for appearance, performance, and the like, to become a product. Some are cut to the size of a steel desk or kotatsu board before shipping. Through these steps, waste materials such as trimmings of decorative panels, sawdust, cutting powder, and sanding powder are discharged. This waste material preferably has a particle size of 2
Pulverized to 50 μm or less. For example, the big one
After crushing with a two-shaft crusher, coarsely crushing with a cutter mill, and finely crushing with a turbo mill, the mixture is sieved with a mesh size of 60 mesh, and large particles are crushed again to form a powder. This powder can be added, for example, as a substitute for wood powder of the phenolic resin molding material and recycled.

As described above, the particle size is preferably 250 μm.
When the decorative board waste material powder pulverized to m or less is recycled and used for the melamine decorative board, it can be added to the core phenol resin liquid. However, since this powder has a large amount of fiber, it has a large water absorption, and even if it is added to a phenol resin liquid in a small amount, the viscosity is significantly increased. Improve water absorption to increase the amount added to the phenolic resin liquid, and as a method of recycling melamine resin waste liquid, add the emulsifier described above,
The suspension-hardened waste liquid and the powder of the decorative board waste material are mixed, dried, and re-ground. The mixing ratio is preferably about 50 to 200 parts by weight of the waste liquid suspended and hardened with respect to 100 parts by weight of the powder of the decorative board waste material. If the amount of the waste liquid is less than 50 parts by weight, the effect of improving the water absorption is reduced. Although it may exceed 200 parts by weight, the more waste liquid, the more drying energy is required. In order to facilitate drying, the amount of the waste liquid is preferably 200 parts by weight or less.

Various mixers and kneaders can be used for mixing the powder of the waste melamine resin decorative board with the hardened melamine resin waste liquid. Although the resin component of the melamine resin waste liquid is hardened, the emulsifier serves as an adhesive, so that it is more effective to knead the resin sufficiently during mixing.
If the mixture is loosened as small as possible and dried, the crushing step after drying can be omitted. Drying may be natural drying, but drying at 105 to 140 ° C. is preferable because the drying time may be relatively short. If the temperature exceeds 150 ° C., the resin cured product and the decorative board waste material powder are thermally decomposed and should be avoided. This heat drying can be carried out, for example, by placing it in a shallow stainless steel vat with a dryer at 120 ° C. for 3 to 4 hours. Next, the dried mixture is reground.
Milling uses a general mill such as a ball mill or jet mill, but if devised at the solidification stage, as described above, only milling can be used, which can reduce the cost of the milling process. It is preferable because it is possible. Thereafter, the pulverized material is applied to a phenolic resin-impregnated base material and is blended with a resin liquid to be provided to a core material. The particle size of the pulverized material is preferably set to 250 μm or less. 250 μm
The above materials may cause problems in the appearance (particularly, surface smoothness) of the recycled decorative board, and are preferably removed.

The paper used for the core is unbleached kraft paper. Conventionally, in order to improve the appearance of the decorative board, a paper specially formed for the decorative board and having a good texture was used. However, according to the method of the present invention, since phenol resin liquid to which powder is added is applied, corrugated cardboard paper having relatively poor texture can be used. As phenolic resin liquid,
Usually, a resol type in which phenol (P) and formaldehyde (F) are reacted with an alkali catalyst at a molar ratio (F / P) of 1.0 to 2.0, and a relatively high water-soluble type is used. use. In order to improve water solubility, for example, a combination of calcium hydroxide and barium hydroxide is used as an alkali catalyst.

As the impregnating device, a device for ordinary decorative plate impregnated paper can be used. For example, paper unwinding equipment, resin liquid impregnating equipment consisting of a varnish bat that impregnates the paper with the phenolic resin liquid in a dip method and a squeeze roll that adjusts the amount of resin impregnated in the paper, a hot air circulation type drying drum of an air support method, Roll coater equipment for applying a high-viscosity phenolic resin liquid with powder added in the middle to one or both sides by a roll method, and a cutting device such as a hot-air circulation type drying drum and cooling roll of an air support method, a rotary cutter,
This is an apparatus consisting of equipment for stacking impregnated paper cut on a pallet. Using such a device, the paper for the core is impregnated with the phenol resin liquid, dried to the extent that there is no "stickiness", and then coated with a high-viscosity phenol resin liquid to which powder has been added by a roll coater, It is further dried to the desired volatile content and cut to size.

A plurality of phenolic resin-impregnated papers coated with this high-viscosity phenolic resin liquid are stacked, a melamine resin-impregnated paper is stacked thereon, put between stainless steel plates, pressed with a press, and formed under ordinary molding conditions for decorative boards. Then, the layers are integrated.
In this case, when only the melamine resin waste liquid is used, not only the preservability of the waste liquid is poor, but also the core layer contains a large amount of the melamine resin component, so that the decorative board is hard and easily chipped. In addition, when the melamine resin waste liquid without adding an emulsifier is stirred and heated to make the resin component fine particles, the storage stability of the liquid is good, but when using these fine particles, even if the powder of the decorative board waste material is mixed, The veneer is still hard and easily chipped. A suspension prepared by adding an emulsifier to the suspension and hardening has a good preservability of the liquid, and the decorative board is flexible, and a decorative board comparable to a conventional decorative board can be obtained.

[0016]

Embodiments of the present invention will be described below. In a reaction vessel equipped with a stirrer equipped with an inverter that can regulate the number of revolutions with a jacket through which steam and water can flow separately, melamine resin waste liquid with a resin content of 40% 100K
g, add 4 kg of PVA, and add 50 kg of water.
In addition, 2 hours at 90 ° C. with stirring at 400 rpm.
After heating for a time to cure the resin, the resin was cooled to room temperature to obtain a waste liquid containing cured resin particles having an average particle size of about 30 μm. Melamine resin decorative board waste material is crushed to a size of 10 cm square or less with a biaxial roll crusher, crushed to a size of 5 mm or less with a cutter mill, and 0.5 mm with an impact type pin mill.
After pulverizing to the following, further pulverizing with a turbo mill, the mixture was sieved with a 100-mesh sifter to obtain 100 kg of powder that passed 100 mesh.

100 kg of this powder is placed in a kneader, and 150 kg of a waste liquid containing the cured resin particles is added thereto.
After mixing for a time, it was placed in a stainless steel vat and spread to a thickness of about 5 cm. Hot air circulation type dryer, 1
After drying at 20 ° C. for 30 minutes, the inside of the vat was thoroughly stirred with a scoop to loosen a large lump, and further dried at 120 ° C. for 2 hours. Next, this was pulverized with a pin mill and a turbo mill, and then sieved with a 150-mesh sifter.
72 kg of this powder was added to a phenol resin liquid 4 containing 45% of resin.
The resulting mixture was added to 00 kg and mixed well with stirring.

Next, in the step shown in FIG. 1, a phenol resin-impregnated paper having both surfaces coated with a phenol resin liquid to which powdered decorative board waste was added was obtained. That is, as the core paper 1, 200
g / m ² kraft paper was used. The core paper 1 is unwound, impregnated with a phenolic resin liquid 2 having a resin content of 45%, and dried by heating with an air support type drying cylinder 3 to obtain a resin content (RC).
A phenol resin impregnated paper having 30% and a volatile matter (VC) of 10% was obtained. Further, on both sides of the impregnated paper, a phenol resin liquid to which the above-mentioned suspension-hardened waste liquid was mixed and to which the powder of the decorative board waste material reground was added was applied by roll coaters 4 and 5, and an air-support type drying cylinder was used. 6 and dried by heating. Next, the sheet is cut to a predetermined length by a cutting machine 7 and RC53%,
A phenol resin impregnated paper 8 of 7% VC was obtained.

The configuration of the melamine resin decorative board in the present embodiment is as follows, as shown in FIG. Three sheets of the phenol resin impregnated paper 8 coated with the phenol resin liquid are stacked, one normal phenol resin impregnated paper 9 not coated with the phenol resin liquid is stacked thereon, and a melamine resin for surface makeup is further stacked thereon. 1 stack of impregnated paper 10
Set as a set, polypropylene film 11 for release
And another set was placed in the opposite direction and inserted between the stainless steel mirror plates 12. In this way, 10 veneer boards are stacked in one stage and inserted between the hot plates, and the pressure is set to 80 kg / cm ² by a hydraulic press for veneer production. Perform heating at 160 ° C for 40 minutes,
The steam was removed, and cooling water was passed through for cooling for 30 minutes, and a molded melamine resin decorative board having a thickness of 1.2 mm was taken out.

For the purpose of comparison, a decorative board was manufactured by a conventional method. What differs from the examples is the core layer impregnated paper used. RC30%, VC10 before applying a phenol resin liquid to which a decorative board waste powder is added by a roll coater
% Phenolic resin impregnated paper was used. The impregnated paper for the core layer was heated and press-molded into five sheets. Other than that, it carried out similarly to Example 1.

The characteristics of each of the obtained melamine resin decorative boards are shown below.

[Table 1]

The decorative board obtained in the example had a thickness of about 1.2.
Approx. 120 g / m ^{2 in} mm (40 g per impregnated paper
/ M ² ) of waste material and waste liquid powder, which is about 7.5% based on the weight of the decorative board (about 1.6 kg / m ² ). Further, compared with a case where a decorative board having the same thickness is manufactured by a conventional method, it is possible to save about 0.5 sheets of kraft paper for core. Further, in the conventional method, in the case of phenol-impregnated paper of 30% RC using 200 g / m ^{2 of} kraft paper for core, the thickness after pressurizing and heating is about 0.2 mm. The thickness of the phenol resin impregnated paper after being pressed and heated is about 0.3 mm. Therefore, when a decorative board having a thickness of 1.2 mm is manufactured, the phenolic resin-impregnated paper for core is 5% in the conventional method.
Are required, but according to the method of the present invention, four
One less than the conventional method. Therefore, the number of manufacturing steps for impregnation can be saved, and in this regard, decorative boards can be manufactured at low cost.

[0022]

According to the method of the present invention, it is possible to recycle a melamine resin decorative board waste material and also to recycle a melamine resin waste liquid.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an impregnation step for producing a phenolic resin-impregnated paper used in the present invention.

FIG. 2 is a cross-sectional view showing an example of a combination of impregnated paper in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core paper 2 Phenolic resin liquid for impregnation 3 Air support type drying cylinder 4 Roll coater 5 Roll coater 6 Air support type drying cylinder 7 Cutting machine 8 Phenolic resin liquid coating phenolic resin impregnated paper 9 Normal phenolic resin impregnated paper 10 Melamine resin impregnated paper Paper 11 Polypropylene film for release 12 Stainless steel mirror plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B29L 9:00 F term (reference) 4F204 AA37 AA50 AC04 AD05 AD06 AD08 AD19 AG01 AG03 AH51 FA01 FB01 FB22 FF01 FF21 FG09 FW45 4F301 AA23 BA12 BA21 BE29 BF12 BF25 BF32

Claims (3)

[Claims] 1. An emulsifier is added to a melamine resin waste liquid in a laminated melamine resin decorative board using a melamine resin impregnated paper for a surface decorative layer and a phenol resin impregnated paper for a core layer, and heated with stirring. The suspension-hardened one and the melamine resin decorative board waste were ground and mixed with the powdered one, heated and dried, and then re-ground to make a powder,
A method for producing a decorative melamine resin plate, comprising adding a core phenolic resin solution to one or both surfaces of a core phenolic resin-impregnated paper and using the resultant as a core layer to laminate and integrate. 2. An emulsifier is added to the melamine resin waste liquid, and the mixture is heated and suspended and hardened while stirring, and the melamine resin decorative board waste material is pulverized into powder, mixed, and dried by heating. The method for producing a melamine resin decorative board according to claim 1, wherein the melamine resin board is re-ground to a particle size of 250 µm or less. 3. The method according to claim 1, wherein the emulsifier is polyvinyl alcohol.