JPH06220784A - Method for recovering waste paper and paper recovered - Google Patents

Abstract

PURPOSE:To safely and easily recover paper contaminated with little dust, good in hue and low in deterioration of its physical properties such as mechani cal strength, from such waste paper that a paper base has been laminated with a metallic foil like aluminum foil or plastic layer. CONSTITUTION:This method for recovering waste paper is characterized by recovering paper, through processes (1) to (5) described below, from such waste paper that a paper base has been laminated with at least metallic foil and/or plastic layer. (1) waste paper is disintegrated by treatment with an aqueous alkaline solution prepared by incorporating water with (A) deinking agent/ releasant consisting mainly of a composite made up of silicate compound and carbonate and (B) a penetrant followed by warming, (2) the waste paper disintegrated is diluted with water, (3) coarse dust is removed, (4) fine dust is removed using both heavy-duty and light-duty cleaners after addition of a deaerating agent, and (5) dealkalifying process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting used paper and the recovered paper. More specifically, the present invention relates to a used paper in which metal foil such as aluminum foil or plastic is laminated on a paper base material and dust is mixed therein. TECHNICAL FIELD The present invention relates to a method for recovering paper having less color, good hue, and less deterioration in physical properties such as strength, and the recovered paper.

[0002]

2. Description of the Related Art A paper container for fruit juice, milk or the like has a paper base material on the back surface of which plastics such as polyethylene or a metal foil such as aluminum is laminated, or is coated with wax, or the surface of which is printed. However, when recycled and used in a normal papermaking process, these metals and plastics are finely divided by chemical and physical treatments and mixed into the paper, which causes a great trouble in the paper manufacturing process.
In addition, even if the paper is forcibly recycled, the conventional recycling method cannot completely separate these metals and plastics, so that only paper mixed with dust of bad color can be obtained. Despite the use of excellent pulp, it has not been possible to reuse it as pulp, and it was only used as a toilet roll. The specific gravity of plastics is close to that of pulp fiber, while the weight of metal foil is heavy, so it is difficult to effectively remove both with a conventional dust remover, and it cannot be recycled for paper, so it is incinerated or discarded. This is the current situation. Therefore, in order to save resources and energy, and to recycle and reuse it so as not to impose a burden on the global environment, we collect paper from such waste paper with little dust contamination, good hue, and less deterioration in physical properties such as strength. There is a strong demand to do so.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to obtain a small amount of dust from a used paper in which a metal foil such as an aluminum foil or a plastic is laminated on a paper base material, and a good hue,
It is an object of the present invention to provide a method for easily recovering paper having less deterioration of physical properties such as strength by a simple method and the recovered paper.

[0004]

Means for Solving the Problems In view of the above points, the present inventors have earnestly studied, and as a result, treated used paper in a pulper containing a specific deinking / releasing agent and a penetrating agent to disintegrate,
The present invention has been accomplished by finding that the above problems can be solved by diluting with water to remove coarse dust and then adding a deaerator to remove fine dust. Claim 1 of the present invention
The invention of (1) to (1) to (1) to (1) below from waste paper in which at least a metal foil and / or plastic is laminated on a paper substrate.
A method for recovering used paper is characterized in that the paper is recovered in the step (5). (1) A step of disintegrating waste paper by treating it in an alkaline aqueous solution heated by adding a deinking / peeling agent and a penetrating agent mainly composed of a complex of a silicate compound and a carbonate. (2) A step of diluting with water. (3) A step of removing coarse dust. (4) A step of adding a deaerator and removing fine dust with a heavy cleaner and a light cleaner. (5) Dealkalizing step.

According to a second aspect of the present invention, the deinking / peeling agent is mainly composed of a composite of sodium silicate and sodium carbonate, or further contains a higher fatty acid derivative. This is the method for collecting used paper as described.

In the invention of claim 3 of the present invention, the penetrant is selected from anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and peroxide penetrants. The method according to claim 1, wherein the penetrant is composed mainly of at least one kind.

In the invention of claim 4 of the present invention, the deaeration agent is at least one deaeration agent selected from tributyl phosphate, fatty acid amide, polyether type nonionic surfactant and silicone. The method described in 1.

According to a fifth aspect of the present invention, there is little dust collected from used paper in which at least a metal foil and / or a plastic layer is laminated on a paper base material, and the recovered paper has a good hue, Maintains 90% or more of the strength, elongation and tear strength of the paper before recovery, and
It is a recovered paper characterized in that the measured values (1) to (4) and the L value lightness according to 9208 (measurement method based on a foreign matter measurement chart) are within the following ranges. (1) Average visual field of 15 or less, (2) Dust area ratio (%) of 0.0300 or less, (3) Total dust area (mm ² / m ² ) of 100 or less, (4) Standard deviation of 50 or less. (5) L value lightness of 92 or more.

When recovering the paper having the above characteristics from the waste paper in which the metal foil such as aluminum foil or the plastic is laminated on the paper base material, the waste paper may be used as it is or may be appropriately cut and used. When cutting, known machines, devices, and methods such as shredders can be used. Although the degree of cutting is not particularly limited, the width 20
mm or less, preferably 10 mm or less.

The heating during disintegration by treating in an alkaline aqueous solution is from room temperature to 100 ° C. or less, preferably from room temperature to 8
The temperature is 0 ° C or lower, and more preferably from room temperature to 70 ° C or lower.
The pH of the alkaline aqueous solution is 8 to 12, preferably 9 to 1.
It is 1. It is preferable to stir in order to disaggregate the waste paper. The stirring means is not particularly limited, and known machines, devices and methods can be used. The treatment time is the time until the disintegration of waste paper is sufficiently performed, and is appropriately selected.

The deinking / releasing agent used in the present invention is a deinking / releasing agent mainly composed of a complex of a silicate compound and a carbonate. The above composite may be a mixture of a silicate compound and a carbonate. The silicate compound and carbonate are not particularly limited, and examples of the silicate compound include sodium silicate, sodium orthosilicate,
Sodium sesquisilicate, sodium metasilicate, powdered sodium silicate, sodium silicate solution, potassium silicate, as well as the carbonate compound, sodium carbonate, sodium bicarbonate, potassium carbonate and the like can be mentioned. The molecular formula of sodium silicate is generally represented by Na ₂ O · nSiO ₂ , where n is a molar ratio: SiO ₂ / Na ₂ O weight ratio × 1.0.
32 is shown and n = 0.5 to 4 is industrially produced, but any of these can be used in the present invention. The deinking / peeling agent used in the present invention may further contain a higher fatty acid or a derivative thereof. The amount of deinking / releasing agent used in the present invention is about 0.5 to 2.0% by weight, preferably about 0.7, based on the paper.
~ 1.5% by weight. When it is 0.5% by weight or less, the time for deinking / peeling becomes long, and the size of foreign matter to be removed is preferably about 10 mm, but it becomes finer than that and cannot be efficiently removed. If it is 2.0% by weight or more, the pH becomes high, and the hue of the paper is deteriorated due to the color of the paper and the burn.

The penetrant used in the present invention is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, a peroxide penetrant, and the like, and mixtures thereof. Specifically, polyoxyethylene alkyl ether, single chain length polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether and the like can be preferably used, but they are not particularly limited thereto. Not a thing. The amount of penetrant used in the present invention is 0.1 to 3.0% by weight, preferably 0.5 to
It is 2.0% by weight. If it is 0.1% by weight or less, the peeling time becomes long and the foreign matter cannot be removed efficiently.
When the amount is 3.0% by weight or more, the color of the paper is damaged and the hue is deteriorated, and it becomes difficult to remove the penetrant in a later step.

The degassing agent used in the present invention is tributyl phosphate, fatty acid amide, polyether type nonionic surfactant, silicone and the like and mixtures thereof. Examples of fatty acid amides include monoamides, substituted amides, methylol amides, and bisamides. The silicone is not particularly limited, and liquid silicone can be preferably used. The addition amount of the deaerator used in the present invention is 0.
It is 1 to 2.0% by weight, preferably 0.5 to 1.0% by weight. If it is less than 0.1% by weight, bubbles cannot be removed,
The foreign matter cannot be removed efficiently. If the content is 2.0% by weight or more, it is uneconomical, and there are problems such as slipping on the surface of the recovered paper, inability to write letters, and bleeding, which necessitates increasing the amount of sizing agent added. is there.

The heavy and light cleaners and other devices used in the present invention are not particularly limited and, for example, commercially available products can be used.

[0015]

In the present invention, the silicate compound in the deinking / peeling agent, which is mainly composed of a composite of a silicate compound and a carbonate, carries out the deinking action, while the carbonate decomposes to form a carbonate. When gas is generated and waste paper is stirred in a pulper, separation of metal foil and plastics is promoted along with deinking. After removing the coarse metal foil or plastics, the fine metal foil or foreign matter on the plastics adheres to the paper fibers along with air bubbles,
Although difficult to remove, the use of a degassing agent facilitates separation.

[0016]

EXAMPLES Hereinafter, the collected paper and the collecting method of the present invention will be described in detail with reference to Examples, but the present invention is not limited to the examples without departing from the gist of the present invention. FIG. 1 shows a system for collecting paper from waste laminated paper by the method of the present invention. The method of the present invention will be described with reference to FIG.
Waste paper, in which metal foil such as aluminum foil or plastic is laminated on a paper base material, is put into the storage tank 1. It is sent to the shredder 2 by a conveyor belt and cut into a width of 20 mm. The cut waste paper is sent by air and the dust is removed by the dust remover 3.
Put in pulper 4. Pulper 4 has a waste paper density of about 5
7% by weight, deinking / releasing agent for paper (sodium silicate /
1% by weight of sodium carbonate complex), 1% by weight of ether type penetrant (trade name: JN-70, manufactured by Nakamura Shosha Co., Ltd.), pH about 12, and a heated aqueous solution at a temperature of 60 ° C. at a rotation speed of 500 rpm. It is agitated, and the waste paper is sufficiently disaggregated within a residence time of about 10 minutes. Foreign matter such as disintegrated aluminum foil is washed with the aqueous solution by hydra purge (4-1), the cleaning liquid is sent to the blow chest 5, the aluminum foil is separated by the selective purge (4-2), and the aqueous solution is sent to the pulper 4. To recycle.

A used paper slurry is prepared by blow chest 5 to a used paper concentration of about 2%. The waste paper slurry is sent to the deflaker 6 and further disintegrated to sufficiently loosen the long fibers. The waste paper slurry is sent to a centric cleaner 7 for roughly removing heavy foreign matters, and then sent to a slit screen 8 for removing coarse aluminum foil. The pH of the waste paper slurry is adjusted in the rough selection chest 9 and then sent to the slit screen 10 for removing the medium-sized aluminum foil. Used paper slurry is 0.5% by weight of tributyl phosphate as degassing agent
After adjusting the pH in the primary chest 11 containing (to paper), a heavy cleaner 12 is used to remove heavy foreign matter.
The waste paper slurry is sent to the secondary chest 13 for pH.
After preparation, it is sent to a lightweight cleaner 14 that removes fine aluminum foil.

The pH of the waste paper slurry from which the fine aluminum foil has been removed is adjusted in the third chest 15 and then the thickener cleaning 1
6. After passing through the cleaning chest 17 for density adjustment, the refiner 18 for freeness control, and the completed chest 19, the foreign matter such as aluminum foil is sufficiently removed and the waste paper slurry 20 is deinked. The waste paper slurry 20 thus obtained could be used in the same manner as virgin pulp without causing any problems in the ordinary papermaking process. The tails of the centric cleaner 7, the slit screen 8 and the slit screen 10 are made of a Jansson screen 21 to remove foreign matter 22 such as aluminum foil, and the remaining slurry is recycled to the blow chest 5. The tail of the heavy cleaner 12 is recycled to the coarse selection chest 9. The tail of the lightweight cleaner 14 is the primary chest 11
Recycle to.

(Examples 1-2, Comparative Examples 1-6, Reference Example)
According to the system shown in FIG. 1, a waste paper in which a metal foil such as an aluminum foil or a plastic is laminated on a paper base is processed under the processing conditions such as the complexing agent, the penetrating agent, and the pulper shown in Table 1 as the slit screen 8. Paper was collected by performing a Jansson screen (round shape diameter 5 mm) and a slit screen 10 such as a flat screen (6 cuts 0.15 mm). The dust collected on the papers collected in Examples 1 and 2 and Comparative Examples 1 to 6 was measured by the following method, and the results are shown in Table 1. The reference example is a measurement of a mixture of NBKP 70% by weight and LBKP 30% by weight, and Table 1 also shows the measurement results. The strength of the paper and the optical properties of the paper recovered in Example 2 and the paper of the reference example were measured by the following methods. The results are shown in Table 2.

(Pulp Dust Measurement Method) JIS P92
08 (Measurement method based on foreign matter measurement chart). (Measurement Method of Basis Weight, Tensile Strength, Bursting Strength, Tear Strength) Basis Weight: According to JIS P8111. Tensile strength: According to JIS P8113. Bursting strength: According to JIS P8113. Tear strength: According to JIS P8116. (Hue measurement method) L by a color difference meter manufactured by Nippon Denshoku Co., Ltd.
A and b were measured.

[0021]

[Table 1]

[0022]

[Table 2]

From the results shown in Tables 1 and 2, in Examples 1 and 2, since the waste paper in which the metal foil such as aluminum foil or the plastic is laminated on the paper base material, dust is less mixed and the hue is reduced. Good quality paper with little deterioration in physical properties such as strength, NBKP 70% by weight of reference example, LBKP3
It can be seen that the paper having almost the same properties as the 0 wt% mixed product could be recovered. On the other hand, the papers collected in Comparative Examples 1 to 6 have poor dust evaluation results and are insufficient.

[0024]

Industrial Applicability According to the method of the present invention, it is possible to obtain a paper having a small amount of dust mixed in, good hue, and less deterioration in physical properties such as strength from waste paper in which a metal foil such as aluminum foil or plastic is laminated on a paper base material. It can be simply, safely and easily collected. Currently, in order to save resources and energy and to recycle and recycle to avoid impacting the global environment, we collect paper from such waste paper with little dust contamination, good hue, and less deterioration in physical properties such as strength. Therefore, the present invention can be expected to make a great contribution to it, so that its industrial utility value is great.

[Brief description of drawings]

FIG. 1 is a flow sheet showing a system for collecting paper from waste laminated paper by the method of the present invention.

[Explanation of code] 1 storage tank, 2 shredder, 3 dust remover, 4 pulper, 5 blow chest, 6 deflaker, 7 centric cleaner, 8 slit screen, 9 coarse selection chest, 10 slit screen, 11 primary chest, 12 weight cleaner , 13 2nd Chest, 14 Lightweight Cleaner, 15 3rd Chest, 16 Thickener, 17 Wash Chest, 18 Refiner, 19 Finished Chest, 20 Waste Paper Slurry, 21 Yangson Screen, 22 Lame lees.

Front page continuation (72) Inventor Tetsuo Sato 5-21-1, Oji, Kita-ku, Tokyo Jujo Paper Co., Ltd. Technology Development Center (72) Inventor Takemitsu Umeki 5-21-1, Prince, Kita-ku, Tokyo Jujo Paper Technology Development Center Co., Ltd. (72) Inventor Shinichi Suzuki 5-21-2 Oji, Kita-ku, Tokyo Jujo Paper Co., Ltd. Liquid Packaging Center (72) Inventor Yu Kobayashi 28 Kanda Higashi-Matsushitamachi, Chiyoda-ku, Tokyo Address In the Nakamura Trading Company (72) Inventor Shigeo Harasawa 28 Kanda Higashi Matsushita Town, Chiyoda-ku, Tokyo Inside Nakamura Trading Company

Claims (5)

[Claims] 1. A used paper having at least a metal foil and / or a plastic laminated on a paper base material, and
A method for recovering used paper, characterized in that the paper is recovered by the steps (5) to (5). (1) A step of disintegrating waste paper by treating it in an alkaline aqueous solution heated by adding a deinking / peeling agent and a penetrating agent mainly composed of a complex of a silicate compound and a carbonate. (2) A step of diluting with water. (3) A step of removing coarse dust. (4) A step of adding a deaerator and removing fine dust with a heavy cleaner and a light cleaner. (5) Dealkalizing step. 2. The deinking / peeling agent mainly comprises a complex of sodium silicate and sodium carbonate, or further contains a higher fatty acid derivative.
How to recover the waste paper described. 3. The penetrant contains at least one selected from anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants and peroxide penetrants as a main component. The method according to claim 1, which is a penetrant. 4. The degassing agent is tributyl phosphate,
Fatty acid amide, polyether type nonionic surfactant,
The method of claim 1, wherein the at least one degassing agent is selected from silicone. 5. A recovered paper having a good hue and a small amount of dust collected from used paper in which at least a metal foil and / or a plastic layer is laminated on a paper base material, and the strength and elongation of the paper before recovery are excellent. And 90% or more of the tear strength are retained, and the measured values (1) to (4) and L value brightness according to JIS P9208 (measurement method based on a foreign matter measurement chart) are within the following ranges. And the recovered paper. (1) Average visual field of 15 or less, (2) Dust area ratio (%) of 0.0300 or less, (3) Total dust area (mm ² / m ² ) of 100 or less, (4) Standard deviation of 50 or less. (5) L value lightness of 92 or more.