JP2001246607A - Recovered paper board and method of manufacturing the recovered paper board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a waste paper board having desired characteristics while maintaining good releasability (peelability) between a hot plate and a board in a hot press process, stably for a long period of time. Provided is a method of manufacturing a waste paper board capable of performing the above-described method, and a waste paper board having desired characteristics manufactured by the manufacturing method. SOLUTION: In the raw material for the core layer, a polyisocyanate compound is used as a binder, and in the raw material for the surface layer, at least a part of the defibrated fiber, the board cutting waste material generated in the process of manufacturing the used paper board. In addition to using materials that were not turned into products such as cutting chips, broken boards, etc. (board waste), dry-fibrillated thermosetting resins other than polyisocyanate were used as binders. Thereby, the releasability from the hot plate of the hot press device is ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste paper board and a method for producing the same. More specifically, a board material obtained by blending a binder with a defibrated fiber obtained by defibrating waste paper such as newsprint, magazine, or corrugated cardboard is prepared by using a hot plate. The present invention relates to a used paper board manufactured through a step of forming a board by heating and pressing (hot pressing step) and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a large amount of waste paper discharged from factories, offices, or ordinary households has been reused for various purposes from the viewpoint of environmental protection and effective use of resources. It is supposed to be. As one of the recycling methods, there is known a method of manufacturing a used paper board used for a building material or the like from used paper.

[0003] One of the methods of manufacturing waste paper boards is as follows.
For example, a method for manufacturing a used paper board in which a board material obtained by adding a binder to a defibrated fiber obtained by dry defibration of used paper is heated and pressed by a hot plate, and is formed into a board shape using a so-called hot press method. There is.

A hot press apparatus used in the above-mentioned method for manufacturing a used paper board is usually provided with a hot plate to maintain good releasability (peelability) between the hot plate and a material to be pressed (board). A release plate (for example, a substrate made of an Al alloy coated with a fluororesin) is attached to the surface, and the hot plate is configured to be pressed against the board material via the release plate. I have.

However, when used repeatedly for a long period of time, the release layer made of the fluororesin coating wears out, and
There is a problem that the base material made of the alloy is exposed and the releasability (peelability) from the board is reduced, and from the viewpoint of long-term stable operation, the reliability is not always sufficient. is there.

The present invention solves the above-mentioned problems, and keeps the releasability (peelability) between a hot plate and a board in a hot pressing process in good condition, stably for a long time, and achieves desired characteristics. It is an object of the present invention to provide a method of manufacturing a used paper board capable of efficiently manufacturing a used paper board having the same, and a used paper board having desired characteristics manufactured by the manufacturing method.

[0007]

In order to achieve the above object, a method of manufacturing a used paper board according to the present invention (claim 1) comprises:
A recycled paper board with a three-layer structure in which the core layer and the surface layer are made of raw materials (board materials) with different components for the core layer and the surface layer, using the defibrated fiber obtained by dry-fibrillation of the waste paper. The board material laminate having a three-layer structure in which surface board material (layer) is disposed on both sides of the core board material (layer) is heated and pressed by a hot plate. It is equipped with a process of forming into a board (hot pressing process). In addition, as a raw material for the core layer board, to a fibrillated fiber obtained by dry fibrillating waste paper as a main raw material, and as a binder, a polyisocyanate compound as a binder 5-15
The board raw material added in the proportion of weight% is used, and as the board material for the surface layer, the material that did not become a product such as board cutting waste material, cutting waste, broken board, etc. generated in the manufacturing process of waste paper board (hereinafter Good releasability from hot plate in hot pressing process other than polyisocyanate compound as binder, for defibrated fiber in which defibrated fiber obtained by dry defibration of “board waste” is used as at least a part It is characterized in that a surface board material obtained by adding a suitable thermosetting resin is used.

[0008] In the board material for the core layer, a polyisocyanate compound is used as a binder in an amount of 5 to 1 on a dry basis.
Used at a ratio of 5% by weight, and in the raw material for the surface layer, at least a part of the defibrated fiber, a board cutting waste material, a cutting waste, generated in a manufacturing process of a used paper board,
By using dry-fibrillated material (board waste material) that was not turned into a product such as a damaged board and using a thermosetting resin with good mold release properties other than polyisocyanate as a binder, the entire board can be used. Mainly the properties such as mechanical strength of the core layer are secured by the core layer, and the releasability from the hot plate of the hot press device can be secured by the surface layer, and the waste paper board with the desired properties can be efficiently manufactured. It becomes possible. As a binder to be added to the core layer board raw material, a mixture of a polyisocyanate compound and another binder may be used in some cases.

In the raw material for the surface layer board, since at least a part of the defibrated fiber is obtained by dry defibration of board waste generated in the manufacturing process of waste paper board, the board waste can be efficiently removed. Use
It is possible to reduce the cost and to construct a closed system. In addition, since the board waste has been defibrated in the past and contains a binder, it is defibrated again, a side binder is added, and when used as a surface layer board material, The fiber state becomes uniform, and the amount of unfibrillated paper chips is greatly reduced compared to the case where virgin waste paper is defibrated, and the peel strength (adhesion strength) with the core layer can be improved. After the defibration, the binder is added again, so that the content of the resin is increased, and it is possible to improve the water resistance and the dimensional stability. In the present invention, the core layer does not necessarily have to have a single-layer structure, and may have a multi-layer structure in some cases.

[0010] In a second aspect of the present invention, the thermosetting resin used for the surface layer board material is a phenol resin, an acrylic resin, an epoxy resin, or the like.
It is characterized by being at least one selected from the group consisting of a vinyl acetate resin and a urethane resin.

The use of at least one selected from the group consisting of a phenolic resin, an acrylic resin, an epoxy resin, a vinyl acetate resin, and a urethane-based resin as the thermosetting resin added to the raw material for the surface layer board provides mechanical The mold releasability from the hot plate of the hot press apparatus can be kept good without sacrificing the strength and the like, and the present invention can be made effective.

In a third aspect of the present invention, the thermosetting resin used for the surface layer board material is a water-dispersible phenolic resin, and the mixing ratio of the water-dispersible phenolic resin. Is a ratio of 5 to 20% by weight on a dry basis.

By using a water-dispersible phenolic resin as the thermosetting resin added to the raw material for the surface layer board, and by setting the mixing ratio (addition amount) to a ratio of 5 to 20% by weight on a dry basis, While suppressing an increase in cost, while securing characteristics such as mechanical strength, it is possible to maintain good releasability from a hot plate of a hot press device, and the present invention can be further effectively demonstrated. .

Further, in the method for producing a recycled paper board according to claim 4, as a main raw material of the defibrated fiber constituting the raw material for the surface layer, it is generated when the periphery of a board formed through a hot pressing step is cut. It is characterized by using scrap materials.

In the case of manufacturing a used paper board, a considerable amount of offcuts is generated when cutting the periphery of a board formed through a hot pressing process. By using this scrap material as the main raw material of the defibrated fiber constituting the raw material for the board, it becomes possible to use the board waste material very efficiently,
It becomes possible to make the present invention effective.

Further, in the method for manufacturing a waste paper board according to the fifth aspect, the thickness of the core layer in the waste paper board as a product is 4 to 2 times.
A board raw material laminate having a three-layer structure in which surface raw materials (layers) are disposed on both sides of the core raw material (layers) so that the thickness of the surface layer becomes 0.3 mm to 1.0 mm. Is subjected to a hot press process.

On both sides of the core layer board material (layer), the surface layer board is formed so that the thickness of the core layer in the waste paper board as a product is 4 to 20 mm and the thickness of the surface layer is 0.3 to 1.0 mm. By disposing the raw materials (layers) and subjecting the three-layer board raw material laminate to a hot pressing process, the surface layer can sufficiently fulfill the function of improving the releasability. Can be made effective.

A method of manufacturing a waste paper board according to a sixth aspect of the present invention is a waste paper board (used board) manufactured by the method of the present invention and / or a product such as board cutting waste material, cutting waste, or broken board. The method is characterized in that the unreacted material (board waste material) is roughly pulverized, and then dry-fibrillated, and used as at least a part of the core layer board raw material.

After the used board and / or board waste is roughly pulverized, dry defibrated fibers (recycled defibrated fibers) (broadly used paper defibrated fibers) are converted into at least a part of the core layer board raw material. When used, the used paper board can be recycled, and it is possible to better meet the demand for resource saving.

When using defibrated fibers (recycled defibrated fibers) obtained by dry defibration of used boards and / or board waste materials, the ratio of the recycled defibrated fibers is usually set to 60% by weight of the whole defibrated fibers. % Or less, and in this case, it is possible to obtain a waste paper board that is substantially inferior to the case where only defibrated fibers from waste paper are used.

However, depending on the characteristics required for the product, the entire amount of the defibrated fibers constituting the core layer board material can be covered by the recycled defibrated fibers. In addition, when the recycled defibrated fiber is used as a core layer board material, the required bending strength can be realized by increasing the amount of the binder (adhesive) added, and the disadvantage of increasing the amount of the binder used is obtained. This is an effective means if the advantages of using recycled defibrated fibers are greater than those.

The waste paper board according to the present invention (claim 7) is a waste paper board manufactured by the method for manufacturing a waste paper board according to any one of claims 1 to 6, wherein the waste paper board contains a defibrated fiber obtained by defibrating waste paper as a main component. And a core layer material in which a polyisocyanate compound is used as a binder at a ratio of 5 to 15% by weight on a dry basis, and at least a part of which is laminated on both front and back surfaces so as to sandwich the core layer material. In addition, defibrated fibers obtained by dry defibration of board waste materials that were not turned into products such as board cutting waste materials, cutting waste, and damaged boards are used.
Further, it is characterized in that a thermosetting resin having good releasability other than polyisocyanate is used as a binder and a surface layer material used at a ratio of 5 to 20% by weight on a dry basis.

The waste paper board of the present invention is a waste paper board manufactured by the method for manufacturing a waste paper board according to any one of claims 1 to 6, wherein the fiber is a defibrated fiber obtained by defibrating waste paper. And a polyisocyanate compound as a binder, wherein the polyisocyanate compound is used as a binder at a ratio of 5 to 15% by weight on a dry basis. Fiber laid fibers obtained by dry-fibrillating board waste materials that were not turned into products such as board cutting waste materials, cutting waste, and damaged boards at least in part are used, and a binder other than polyisocyanate is used as a binder. Since the thermosetting resin having good moldability has a laminated structure including a surface material used at a ratio of 5 to 20% by weight on a dry basis, mechanical strength and Together has excellent properties relates such as an aqueous, for releasability is excellent in the heat plate of the hot press apparatus used in the molding process, it can be efficiently produced by the production method of the present invention.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be shown and the features thereof will be described in more detail. FIG. 1 is a flow sheet showing a method for manufacturing a used paper board according to an embodiment of the present invention.

The method of manufacturing the used paper board of this embodiment is as follows.
As shown in FIG. 1, as a main step, a series of steps S1 for forming a core layer, a series of steps S2 for forming a surface layer, a core layer and a surface layer are laminated, and heated and pressed. And a series of steps S3 for finishing the product.

A series of steps S1 for forming the core layer includes:
The main steps are: a waste paper crushing step A1 for coarsely crushing waste paper raw material; a waste paper dry defibration step B1 for dry defibrating coarsely crushed waste paper raw material; and a binder addition step C1 for adding and mixing a polyisocyanate compound as a binder. And a core layer forming step D1 of expanding a waste paper raw material (core layer board raw material) to which the polyisocyanate compound is added and forming it into a layer.

The used paper crushing step A1 is performed in newspapers, magazines,
This is a step of coarsely pulverizing waste paper raw materials such as corrugated cardboard into a shape that can be supplied to a dry defibrating machine. In addition, when coarsely-pulverized waste paper raw material is supplied, pulverization may not be necessary in some cases.

The waste paper dry defibration step B1 is a step of dry defibration of coarsely crushed waste paper raw material.
Waste paper raw material is sufficiently defibrated to form a fiber.

The binder addition step C1 is a step of adding and mixing a polyisocyanate compound as a binder. Here, as the polyisocyanate compound, diphenylmethane diisocyanate was used, and was added at a ratio of 8% by weight and 10% by weight on a dry basis.

In the core layer forming step D1, the waste paper raw material (core layer board raw material) to which the polyisocyanate compound is added is formed (expanded) into a layer (mat-like molded body) having a predetermined shape and thickness. ) Process.

In the series of steps S2 for forming the surface layer, as a main step, a material (board waste material) which has not become a product (board waste material) such as board cutting waste material, cutting waste, and damaged board is roughly crushed. Board waste material crushing process A2 and waste material dry defibration process B for dry defibration of coarsely crushed board waste material
2. Add thermosetting resin that functions as a binder
The method includes a thermosetting resin adding step C2 for mixing, and a surface forming step D2 for expanding the surface layer board material to which the thermosetting resin is added and forming the material into a layer.

The board waste material pulverizing step A2 is a step of coarsely pulverizing board waste material that has not been turned into a product such as board cutting waste material, cutting waste, or a damaged board until the board waste material can be supplied to a dry defibrating machine. In this embodiment, a cut off material generated when cutting the periphery of a board formed through a hot pressing process described later was used as a surface layer board raw material. However, it is also possible to use cutting waste, a damaged board, or the like.

The waste material dry defibration step B2 is a step of dry defibrating the coarsely pulverized cut scraps.
The cut off material is sufficiently defibrated to form a fiber.

The thermosetting resin addition step C2 is a step of adding a thermosetting resin other than the polyisocyanate compound, which is excellent in releasability from a hot plate of a hot press device. In this embodiment, a water-dispersible phenol resin was used as the thermosetting resin having excellent release properties, and was added at a ratio of 10% by weight on a dry basis.

In the surface forming step D2, the surface board raw material to which the water-dispersible phenol resin is added is
This is a step of forming (spreading) into a layer (mat-like formed body) having a predetermined shape and thickness.

In a series of steps S3 of laminating the core layer and the surface layer, heating and pressing, and finishing the product, the board material for the surface layer is disposed on both the front and back surfaces of the board material (layer) for the core layer. (Laminating) a core layer / surface layer laminating step E of forming a three-layer board raw material laminate composed of a core layer and a surface layer; a prepress step F of preliminarily forming the board raw material laminate; A forming process (hot pressing process) G in which the formed board raw material laminate is heated and pressed by a hot plate under predetermined conditions to form a board shape, and a formed product (board) is finished to a final product (recycled paper board). And a product finishing step H.

In the core layer / surface layer laminating step E, the surface layer forming step D is performed on both front and back surfaces of the core layer board raw material (layer) formed in a mat shape in the core layer forming step D1.
This is a step of laminating the board material (layer) for surface layer formed into a mat shape in Step 2 to form a board material laminate having a three-layer structure. In this embodiment, as shown in FIG. 2, the thickness of the core layer 2 in the waste paper board 1 as a product is about 11 mm,
The board material (layer) for the surface layer was laminated on both sides of the board material (layer) for the core layer such that the thickness of each of the surface layers 3a and 3b disposed on both the front and back surfaces of the layer became about 0.5 mm. .

In this embodiment, in the waste paper board 1 as a product, the thickness of the core layer 2 is about 11 mm, and the thickness of the surface layers 3a and 3b on both front and back sides is about 0.5 mm. The core layer and the board material for the surface layer were laminated so that the thickness of the board material layer for the core layer before pressing was about 280 mm, and the thickness of each of the board material layers for the surface layer was about 10 mm.

The pre-pressing step F is performed in a predetermined shape,
This is a step of preliminarily pressing a three-layer board raw material laminated body laminated to a thickness.

In the forming step (hot pressing step) G, the prepressed three-layered board raw material laminate is heated and pressed by pressing a hot plate from both front and back sides through spacers of a predetermined thickness. This is a step of forming a board by tightening. In this embodiment, (a) clamping pressure: 18 kgf / cm 2 (b) heating temperature: 180 ° C. (c) heating / clamping time: 10 minutes (d) spacer thickness: 12 mm went. Note that the hot pressing step can be performed in a single-stage method, or a multi-step method including a secondary hot pressing step such as a primary hot pressing step and a secondary hot pressing step, or a continuous method. It is also possible.

In this step, the polyisocyanate compound in the core layer board material is cured to form a binder (adhesive).
In addition, the water-dispersible phenolic resin in the surface layer board material cures and functions as a binder (adhesive), and the phenolic resin separates from the hot plate of the hot press device. It exerts moldability (peelability) and functions to prevent the molded board from adhering to the hot plate.

The product finishing step H is a step of cutting and trimming a molded body (board) to finish a final product (waste paper board) having a predetermined size.

According to the method of manufacturing a waste paper board of the above embodiment, the releasability (peelability) between the hot plate and the board of the hot press apparatus is stably maintained for a long time, and a sufficiently stable operation is achieved. It was possible to do it for a long time.

Further, in the above embodiment, as the core layer board raw material, a binder obtained by using a defibrated fiber obtained by dry-fibrillating waste paper, which is a main raw material, is used. Used paper board (used board) and / or material that did not become a product such as board cutting waste, cutting waste, damaged board, etc. (board waste)
Can be used as at least a part of the core layer board raw material by using a defibrated fiber (recycled defibrated fiber) that has been coarsely pulverized and then dry defibrated.

In addition, as the recycled defibrated fiber,
We used defibrated fibers obtained by dry-fibrillation of offcuts (cut offcuts) generated when cutting the periphery of a board formed through a hot pressing process, and used it by mixing with defibration fibers from waste paper. In this case, the mixing ratio of recycled defibrated fiber (dry basis) and the characteristics of waste paper board (
Tables 1 and 2 show the relationship between the density, the bending strength, and the bending strength, the thickness expansion rate, and the water absorption rate when the density was converted to 0.75. Table 1 shows the case where the amount of the binder added is 8% by weight on a dry basis, and Table 2 shows the case where the amount of the binder is 10% by weight on a dry basis.

[0046]

[Table 1]

[0047]

[Table 2]

In the case where the defibrated fiber from the cut off material is mixed with the defibrated fiber from the waste paper, the blending ratio of the recycled defibrated fiber (mixing of the defibrated material into the main raw material) Fig. 3 shows the relationship between the percentage of recycled paper fiber and the bending strength of the recycled paper board. Is shown in FIG.

As shown in Tables 1 and 2 and FIG. 3, as the proportion of the recycled defibrated fiber from the cut off material increases, the bending strength decreases somewhat, but as shown in FIG. The peel strength is improved. In addition, no significant change was observed in other characteristics.

From the above results, the material (board waste material) which was not made into a product such as used board, board cutting waste material, cutting waste, or damaged board was roughly pulverized and then dried and defibrated to obtain a defibrated fiber (recycled fiber). It can be seen that defibrated fibers can be used as at least a part of the core layer.

The present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the invention with respect to the ratio of the binder to the core layer and the surface layer. is there.

[0052]

As described above, according to the method for producing waste paper board of the present invention (claim 1), the core material for the board for the core layer contains a polyisocyanate compound as a binder in an amount of 5 to 15% by weight on a dry basis. In the raw material for the surface layer board, at least a part of the defibrated fiber, which is not produced as a product such as board cutting waste, cutting waste, or broken board generated in the process of manufacturing waste paper board (board Waste material) is dry-fibrillated, and a thermosetting resin with good release properties other than polyisocyanate is used as a binder.
Mainly the properties such as mechanical strength of the board as a whole are secured by the core layer, and the releasability from the hot plate of the hot press device can be secured by the surface layer, making it possible to efficiently use waste paper boards with the desired properties. It becomes possible to manufacture well.

Further, in the raw material for the surface layer board, since at least a part of the defibrated fiber is obtained by dry defibration of waste board generated in the manufacturing process of waste paper board, waste board is efficiently used. Use
It is possible to reduce the cost and to construct a closed system. In addition, when waste board is used as a board material for the surface layer, the defibration state becomes uniform and compared to the defibrated waste paper (virgin waste paper).
The amount of unfibrillated paper is greatly reduced, and the peel strength (adhesive strength) with the core layer can be improved. Since the binder is added again after defibration, the binder content increases. In addition, such an effect can be obtained that the water resistance and the dimensional stability can be improved.

Further, as in the method for manufacturing a waste paper board according to the second aspect, the thermosetting resin added to the surface layer board material may be a phenol resin, an acrylic resin, an epoxy resin, or the like.
When at least one selected from the group consisting of vinyl acetate resin and urethane-based resin is used, the mold releasability from a hot plate of a hot press device is ensured without sacrificing mechanical strength and the like. It is possible to keep good, and the present invention can be made effective.

Further, as in the method for manufacturing a recycled paper board according to the third aspect, a water-dispersible phenol resin is used as the thermosetting resin added to the raw material for the surface layer board, and the mixing ratio (addition amount) thereof is determined. By controlling the ratio to 5 to 20% by weight on a dry basis, it is possible to secure properties such as mechanical strength and maintain good releasability from a hot plate of a hot press device while suppressing an increase in cost. Is possible, and the present invention can be made more effective.

Further, when manufacturing a waste paper board, a considerable amount of offcuts is generated when cutting the periphery of the board formed through the hot pressing step. By using this scrap material as the main raw material of the defibrated fiber constituting the surface layer board raw material, it becomes possible to use the board waste material extremely efficiently, and the present invention can be made effective.

Further, as in the method for manufacturing a waste paper board according to the fifth aspect, the thickness of the core layer of the waste paper board as a product is 4%.
The board material (layer) for the surface layer is disposed on both sides of the board material (layer) for the core layer so that the thickness of the surface layer becomes 0.3 to 1.0 mm. By subjecting the raw material laminate to the hot pressing step, it becomes possible for the surface layer to sufficiently fulfill the function of improving the releasability, and the present invention can be further made effective.

Further, as in the method for manufacturing a used paper board according to the sixth aspect, a used fiber and / or board waste material is roughly pulverized and then dried and defibrated (recycled defibrated fiber) (recycled paper in a broad sense). When the defibrated fiber is used as at least a part of the core layer board raw material, it becomes possible to recycle the used waste paper board, and it is possible to respond better to the demand for resource saving. .

The waste paper board according to the present invention (claim 7) is a waste paper board manufactured by the method for manufacturing a waste paper board according to any one of claims 1 to 6, wherein the waste paper board is a defibrated fiber (fibrillated fiber) obtained by defibrating waste paper. Is a recycled fibrillated fiber) and a polyisocyanate compound as a binder is 5 to 15% by weight on a dry basis.
The core layer material used in the ratio of, and laminated on both front and back sides so as to sandwich the core layer material, at least partially, did not become a product such as waste board cutting material, cutting waste, damaged board, etc. A fibrillated fiber obtained by dry-fibrillating board waste is used, and a thermosetting resin having good releasability other than polyisocyanate is used as a binder in an amount of 5 to 2 on a dry basis.
Because it has a laminated structure with a surface layer material used at a ratio of 0% by weight, it has excellent characteristics such as mechanical strength and water repellency, and a hot press device used in a molding process. Is excellent in releasability from a hot plate, and can be efficiently manufactured by the manufacturing method of the present invention.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a method for manufacturing a used paper board according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a used paper board manufactured in the embodiment of the present invention.

Fig. 3 Recycled defibrated fiber from cut off material
It is a figure which shows the relationship between the compounding ratio of recycled fiber (the compounding ratio of the remnant defibrated material in a main raw material), and the bending strength of a used paper board, when it mixes with the defibrated fiber from waste paper. .

[Figure 4] Recycled defibrated fiber from cut off material
Relationship between the mixing ratio of recycled defibrated fibers (mixed ratio of scrap defibrated materials in the main raw material) and the peel strength of the core layer and surface layer of recycled paper board when used in combination with defibrated fibers from waste paper FIG.

[Explanation of symbols]

1 Waste paper board (product) 2 Core layer 3a, 3b Surface A1 Waste paper crushing process B1 Waste paper dry defibration process C1 Binder addition process D1 Core layer forming process A2 Board waste material crushing process B2 Waste material dry defibration process C2 Thermosetting resin addition process D2 Surface layer forming step E Core layer / surface layer laminating step F Pre-press step G Forming step (hot press step) H Product finishing step S1 Series of steps for forming core layer S2 Series of steps for forming surface layer S3 Molding Series of processes for finishing products and finishing

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Kanzawa 2-1-2, Kuisejijima, Amagasaki-shi, Hyogo Inside Kimura Kakoki Co., Ltd. F term in Kimura Kakoki Co., Ltd. (reference) 2B260 AA12 BA04 BA15 BA19 BA23 CA02 CB01 CB04 CD02 DA02 DA04 DA05 DA06 DA08 DA09 DA17 DC14 DD03 EA05 EB02 EB21 EC08

Claims (7)

[Claims] A fibrous fiber obtained by dry-fibrillating waste paper as a main raw material, and a raw material (board raw material) having different components is used for a core layer and a surface layer. A method for producing a recycled paper board having a structure, wherein a board material laminate having a three-layer structure in which surface board material (layer) is disposed on both sides of a core layer board material (layer) is heated by a hot plate.・ It is equipped with a process of pressing and forming into a board shape (hot press process). In addition, as a raw material for the core layer board, a defibrated fiber obtained by dry-fibrillating waste paper, the main raw material, and a polyisocyanate as a binder A board material obtained by adding a compound at a ratio of 5 to 15% by weight on a dry basis is used. As a board material for the surface layer, a board cutting waste material, a cutting waste, a broken board, etc. generated in a manufacturing process of a waste paper board are used. Product The defibrated fiber obtained by dry defibration of the material that did not exist (hereinafter referred to as “board waste material”) is used as a binder at least partially as a binder with a hot plate in a hot pressing process other than a polyisocyanate compound. A method for producing a used paper board, characterized in that a surface board material obtained by adding a thermosetting resin having good release properties is used. 2. The thermosetting resin used for the surface layer board raw material is at least one selected from the group consisting of phenolic resins, acrylic resins, epoxy resins, vinyl acetate resins, and urethane resins. The method for producing a used paper board according to claim 1, wherein: 3. The thermosetting resin used as the surface layer board material is a water-dispersible phenol resin, and
The mixing ratio of the water-dispersed phenolic resin is 5 to 5 on a dry basis.
The method for producing a used paper board according to claim 1, wherein the proportion is 20% by weight. 4. A scrap material generated when cutting the periphery of a board formed through a hot pressing step is used as a main material of defibrated fibers constituting said surface board material. The method for producing a used paper board according to any one of claims 1 to 3. 5. The surface layer on both sides of the core layer board material (layer) so that the thickness of the core layer in the waste paper board as a product is 4 to 20 mm and the thickness of the surface layer is 0.3 to 1.0 mm. The board material laminate having a three-layer structure provided with board materials (layers) is subjected to a hot pressing process.
5. The method for producing a used paper board according to any one of the above items 4. 6. A waste paper board (used board) produced by the method of the present invention and / or used material (board waste material) which is not turned into a product such as board cutting waste material, cutting waste, broken board, etc. The method for producing a used paper board according to any one of claims 1 to 5, wherein the defibrated fiber obtained by dry defibration after coarse pulverization is used as at least a part of a board material for a core layer. 7. A waste paper board produced by the method for producing a waste paper board according to claim 1, wherein a fibrillated fiber obtained by fibrillating the waste paper is a main component, and a polyisocyanate compound as a binder is a dry basis. A core layer material used at a ratio of 5 to 15% by weight, and laminated on both front and back surfaces so as to sandwich the core layer material,
At least in part, defibrated fibers obtained by dry defibration of board cutting waste, cutting waste, board waste that has not become a product such as a damaged board are used, and as a binder, good release properties other than polyisocyanate A waste paper board comprising: a thermosetting resin; and a surface layer material used at a ratio of 5 to 20% by weight on a dry basis.