JPH11227111A - Laminate paper and its reuse method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate easily a base layer composed of a paper material from a synthetic resin layer, reuse the paper material as a regenerated paper and also reuse the synthetic resin layer as regenerated plastic. SOLUTION: A bonding agent layer 7 is formed between a base layer 3 and a synthetic resin layer 5 of a laminate paper 1 provided with the base layer 3 formed of a paper material and the synthetic layer 5. The bonding agent layer 7 is composed of a water-soluble bonding agent, a water dispersion bonding agent or a water macerating bonding agent as main components. When the laminate paper 1 is immersed under water, the bonding agent layer 7 is eliminated or its bonding force is lost to separate easily the base layer 3 from the synthetic resin layer 5. A reinforcing material layer can be formed on the upper side of the synthetic resin layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated paper used for, for example, plain paper copy paper, a resin plate such as an acrylic plate, a steel coil, a steel plate, paper winding, packaging of chemicals, cement, foods and the like, and this laminate. The present invention relates to a paper recycling method, and more particularly to a laminated paper in which a paper material and a synthetic resin layer are laminated, and a method of recycling the laminated paper.

[0002]

2. Description of the Related Art Plain paper copy paper (hereinafter referred to as "P
Laminated paper in which a polyolefin resin such as polyethylene or polypropylene is laminated on a paper material with a thickness of about 15 micrometers is used for packaging of PC paper). In this laminated paper, the polyolefin-based resin prevents water from entering, so that moisture absorption of the packaged material can be prevented.

In recent years, attempts have been made to increase the recycling rate of paper and resin products from the viewpoint of resource saving and environmental protection. However, even if the laminated paper is used as a raw material for recycled paper after use, the polyolefin resin is hardly disintegrated in water, and is not reused at present. It is also conceivable to melt the polyolefin resin of the laminated paper after use and reuse it as recycled plastic.However, paper materials are mixed into the molten resin and the quality of recycled plastic is reduced. It is difficult. For this reason, most of the used laminated paper is actually disposed of or incinerated.

However, when the laminated paper is discarded, the polyolefin-based resin does not decompose in the natural environment, so that the resin remains in the environment and causes environmental destruction. Also, if the laminated paper is incinerated,
Not only does the generation of carbon dioxide gas lead to global warming, but also the burning of the polyolefin resin raises the temperature inside the incinerator and damages the incinerator.

[0005]

If the paper material of the used laminated paper and the polyolefin resin are separated, the paper material can be reused as recycled paper, and the polyolefin resin can be reused as recycled plastic. . However, the conventional laminated paper has a high adhesive strength between the paper material and the polyolefin resin, so that it is not easy to separate the two.

[0006] The present invention has been made in view of these problems, and it is possible to easily separate a base material layer made of paper material and a synthetic resin layer, and therefore to reuse paper material as recycled paper. It is an object of the present invention to provide a laminated paper and a method for reusing the laminated paper, wherein the synthetic resin layer can be reused as recycled plastic.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is directed to a laminated paper having a base material layer made of a paper material and a synthetic resin layer. An adhesive layer is provided therebetween, and a main component constituting the adhesive layer is a laminated paper, which is a water-soluble adhesive, a water-dispersible adhesive or a water-disintegrating adhesive. (Claim 1).

According to the present invention, since the adhesive layer having a water-soluble adhesive, a water-dispersible adhesive, or a water-disintegrating adhesive as a main component is provided, the adhesive layer absorbs moisture. Thereby, the base material layer and the synthetic resin layer can be easily separated. Examples of the synthetic resin that can be easily reused include a polyolefin resin (claim 2). Further, in the case of a laminated paper in which a reinforcing material layer is provided on the upper side of the synthetic resin layer, this reinforcing material layer can be reused (claim 3).

Another invention made in view of the above-mentioned problem is to make the adhesive layer of the laminated paper absorb moisture,
This is a method of recycling laminated paper in which a base material layer and a synthetic resin layer are separated and reused (claim 4).

According to the present invention, the base material layer and the synthetic resin layer can be separated, the base material layer can be reused as recycled paper, and the synthetic resin layer can be reused as recycled plastic.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a laminated paper 1 according to an embodiment of the present invention. The laminated paper 1 includes a sheet-shaped base material layer 3 made of a paper material and a synthetic resin layer 5 made of a synthetic resin. The base layer 3 and the synthetic resin layer 5 are laminated via an adhesive layer 7.

The paper material used for the base material layer 3 only needs to have water disintegration properties, and the material is not particularly limited. Examples of the paper material used include high-quality paper, kraft paper, liner paper, and kenaf paper. Although the thickness of the base material layer 3 depends on the material of the paper material to be used, the use of the laminated paper 1, and the like, it is usually about 50 micrometers or more and 1000 micrometers or less.

The type of the synthetic resin used for the synthetic resin layer 5 is not particularly limited. However, when the synthetic resin is reused as a recycled plastic by heating and melting, the synthetic resin must be a thermoplastic synthetic resin. Among the thermoplastic synthetic resins, polyolefin resins which are available at low cost and are easy to regenerate are preferred. Preferred polyolefin resins include, for example, polyethylene, polypropylene, ethylene vinyl alcohol (EVA), ethylene ethyl acrylate (EEA),
Ethylene-acrylic acid copolymer (EAA) and the like. The thickness of the synthetic resin layer 5 depends on the type of the synthetic resin used, the use of the laminated paper 1 and the like, but is usually about 10 to 50 micrometers.

The adhesive layer 7 contains a water-soluble adhesive, a water-dispersible adhesive or a water-disintegrating adhesive as a main component. The water-soluble adhesive is an adhesive having a property of dissolving in water. Examples of the water-soluble adhesive include a polyvinyl alcohol-based adhesive. The water-dispersible adhesive is an adhesive having a property of being dispersed in water to become an emulsion. Examples of the water-dispersible adhesive include a polyvinyl acetate emulsion-based adhesive. The water-disintegrating adhesive is an adhesive having a property of being solidified and subdivided when immersed in water and floating in water. Examples of the water-disintegrating adhesive include, for example, an adhesive mainly containing a resin obtained by binding a polyhydric alcohol with a vinyl acetate resin, an ethylene vinyl acetate resin, polyester, polyacrylamide, polyacrylic acid, polyamide, or the like. Is mentioned. Specific examples of the water-disintegrating adhesive include, for example, trade names “Cycloflex 70-4485” and “Cycloflex 70-
4396 "," Cycloflex 70-3850 ",
"Cycloflex 70-3780" and the like.

The thickness of the adhesive layer 7 is preferably from 2 to 20 micrometers, particularly preferably from 5 to 10 micrometers.
If the thickness of the adhesive layer 7 is less than the above range, the adhesive strength may be insufficient. Conversely, if the thickness of the adhesive layer 7 exceeds the above range, not only does it take time to separate the paper material from the synthetic resin layer, but also the production cost of the laminated paper may increase.

Next, a method of reusing the laminated paper 1 will be described. First, the used laminated paper 1 is immersed in water. Then, water that has passed through the base material layer 3 that is a paper material reaches the adhesive layer 7. Here, when the adhesive layer 7 is made of a water-soluble adhesive, the adhesive layer 7 is dissolved in water. Also,
When the adhesive layer 7 is made of a water-dispersible adhesive, the adhesive layer 7 is dispersed in water. When the adhesive layer 7 is made of a water-disintegrating adhesive, the adhesive layer 7 floats in water. In either case, the base material layer 3 and the synthetic resin layer 5 are easily separated by the disappearance of the adhesive layer 7 or the inability to maintain the adhesive force. The separated base material layer 3 is disintegrated in water and reused as recycled paper. At this time, high quality recycled paper can be obtained without the synthetic resin being mixed into the recycled paper. The separated synthetic resin layer 5 is heated and melted and reused as recycled plastic. At this time, a high-quality recycled plastic can be obtained without the paper material being mixed into the recycled plastic.

Instead of immersing the laminated paper 1 in water,
The adhesive force of the adhesive layer 7 can also be lost by spray-coating water or spraying water vapor on the base layer 3, so that the base layer 3 and the synthetic resin layer 5 can be easily separated. it can.

Next, an example of a method for manufacturing the laminated paper 1 will be described with reference to FIG. FIG. 2 is a schematic view schematically showing an apparatus for manufacturing the laminated paper 1. In FIG. 2, reference numeral 9 denotes a T-die, reference numeral 11 denotes a cooling roll, and reference numerals 13, 15, and 17 each denote a first transporter. A roll, a second transport roll, and a third transport roll, and a coating roll indicated by reference numeral 19 is a coating roll.

In order to manufacture the laminated paper 1 using this apparatus, first, a paper material sheet 21 is fed into the apparatus by a first transport roll 13. At this time, the adhesive 23 is applied onto the paper material sheet 21 by the coating roll 19. The paper material sheet 21 is further transferred to the second transport roll 1.
5 to the cooling roll 11. Here, the synthetic resin 27 heated and melted from the base 25 of the T-die 9 is used.
Is extruded and laminated on the paper material sheet 21 via the adhesive 23. The synthetic resin 27 is cooled by the cooling roll 11, taken out of the device via the third transport roll 17, and the laminated paper 1 is manufactured.

In this apparatus, the adhesive 23 is applied using the coating roll 19, but the method of applying the adhesive 23 is not limited to the roll coating method. For example, the adhesive 23 may be applied by a spray coat, a gravure coat, or the like.

FIG. 3 is a sectional view of a laminated paper 31 according to another embodiment of the present invention. The laminated paper 31 is made of a paper material and has a sheet-like base material layer 33.
And a synthetic resin layer 35 made of a synthetic resin, and a reinforcing material layer 37 located above the synthetic resin layer 35.
The base layer 33 and the synthetic resin layer 35 are laminated via an adhesive layer 39. The materials and dimensions of the base layer 33, the synthetic resin layer 35, and the adhesive layer 39 are the same as those of the base layer 3, the synthetic resin layer 5, and the adhesive layer 7 of the laminated paper 1 of the embodiment shown in FIG. is there.

The reinforcing material layer 37 is for improving the strength of the laminated paper 31. As the reinforcing material layer 37, a resin cloth, a nonwoven fabric, a resin film, or the like can be used. The thickness of the reinforcing material layer 37 depends on the material of the material to be used, the use of the laminated paper 31, and the like, but is usually about 50 micrometers or more and 500 micrometers or less.

Also in this laminated paper 31, the adhesive layer 39 is lost by immersion in water or the like, or the adhesive layer 3
9 can be lost. Then, the base layer 33, the synthetic resin layer 35, and the reinforcing material layer 37 can be easily separated, and can be reused respectively. At this time, if both the synthetic resin layer 35 and the reinforcing material layer 37 are formed of a thermoplastic resin, the both can be heated and melted together to obtain a recycled plastic. In particular, if the synthetic resin layer 35 and the reinforcing material layer 37 are formed of the same synthetic resin, different synthetic resins are not mixed with each other, and the quality of the recycled plastic can be improved.

Next, an example of a method of manufacturing the laminated paper 31 will be described with reference to FIG. FIG. 4 is a schematic view showing an outline of a manufacturing apparatus of the laminated paper 31. In FIG. 4, reference numeral 41 denotes a T-die, reference numeral 43 denotes a cooling roll, and reference numerals 45, 47, and 49 denote a first transporter. There are a roll, a second transport roll and a third transport roll, and the one denoted by reference numeral 51 is a coating roll.

In order to manufacture the laminated paper 31 using this apparatus, first, the paper material sheet 53 is placed on the first transport roll 45.
Is sent into the device. At this time, the adhesive 55 is applied onto the paper material sheet 53 by the coating roll 51. On the other hand, the reinforcing material 57 is
It is sent to the gap with the transport roll 47. Here, T die 4
The synthetic resin 61 heated and melted from the first base 59 is extruded and laminated with the reinforcing material 57. The synthetic resin 61 is stacked on the paper material sheet 53 via the adhesive 55 while being cooled by the cooling roll 43. Then, the laminated paper material sheet 53, the adhesive 55, the synthetic resin 61 and the reinforcing material 57 are taken out of the apparatus via the third transport roll 49, and
The laminated paper 31 is manufactured.

In this apparatus, the adhesive 55 is applied using the coating roll 51, but the method of applying the adhesive 55 is not limited to the roll coating method. For example, the adhesive 55 may be applied by a spray coat, a gravure coat, or the like.

Although the present invention has been described in detail based on the embodiments, the present invention is not construed as being limited based on these descriptions. In practicing the present invention, for example, another layer may be provided below the base material layer, or another layer may be provided between the adhesive layer and the synthetic resin layer. Various changes are possible.

[0029]

As described above, according to the present invention,
The base material layer made of paper material and the synthetic resin layer can be easily separated, so that the paper material can be reused as recycled paper, and the synthetic resin layer can be reused as recycled plastic. Industrial Applicability The laminated paper of the present invention and the method for recycling this laminated paper are environmentally friendly and can contribute to resource saving and do not destroy the natural environment.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a laminated paper according to an embodiment of the present invention.

FIG. 2 is a schematic view schematically showing the apparatus for manufacturing the laminated paper shown in FIG. 1;

FIG. 3 is a cross-sectional view illustrating a laminated paper according to another embodiment of the present invention.

FIG. 4 is a schematic view schematically showing the apparatus for manufacturing the laminated paper shown in FIG. 3;

[Explanation of symbols]

 1, 31 ... laminated paper 3, 33 ... base material layer 5, 35 ... synthetic resin layer 7, 39 ... adhesive layer 9, 41 ... T die 11, 43 ... cooling Rolls 13, 45: First transport roll 15, 47: Second transport roll 17, 49: Third transport roll 19, 51: Coating roll 21, 53: Paper material sheet 23, 55: adhesive 25, 59: base 27, 61: synthetic resin 37: reinforcing material layer

Claims (4)

[Claims] 1. A laminated paper comprising a base material layer made of paper material and a synthetic resin layer, wherein an adhesive layer is provided between the base material layer and the synthetic resin layer. A laminated paper, wherein a main component constituting the layer is a water-soluble adhesive, a water-dispersible adhesive or a water-disintegrating adhesive. 2. The laminated paper according to claim 1, wherein the synthetic resin constituting the synthetic resin layer is a polyolefin resin. 3. The laminated paper according to claim 1, further comprising a reinforcing material layer located above the synthetic resin layer. 4. The reuse of a laminated paper according to claim 1, wherein the adhesive layer of the laminated paper according to claim 1 absorbs moisture, the base layer and the synthetic resin layer are separated and reused. Method.