JP3262517B2 - Deinking method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to newspapers, flyers,
The present invention relates to a deinking method for deinking and reusing waste paper such as magazines, OA waste paper, and information waste paper. More specifically, the present invention provides excellent deinking pulp having higher whiteness and a smaller number of remaining inks while maintaining an appropriate yield even in the reuse of the washing white water in the flotation process, and has excellent operability. On the deinking method.

[0002]

2. Description of the Related Art Recycling of newspapers, magazines, OA waste paper and the like has been practiced for a long time, but recently, in particular, has been linked to global environmental problems such as protection of forest resources and garbage disposal. It is increasing. In addition, the use of deinked pulp has been advanced to higher-grade pulp as seen in the example of used newspaper to medium-grade paper. On the other hand, recent waste paper is becoming more severe from the viewpoint of deinking due to changes in printing technology, printing method, printing ink components, etc., and a deinking method with high yield and low white ink with moderate yield. The development of is desired. Therefore, for example, various drugs have been conventionally improved.

[0003] Further, as for the treated water used in the deinking process, it is desirable to reduce the amount of use from the aspect of supply and the environment, so that white water is generally recycled.
White water is dewatered and filtered treated water generated in each step of the deinking step. Specifically, in the flotation step, the white water dehydrated in the subsequent washing step or papermaking step is usually circulated and used as diluting water before flotation of the pulp slurry after the aging or bleaching step. . However, such white water circulation accumulates fine ink and fibers in the white water, so that the whiteness decreases as the white water circulation progresses. Further, since the used chemicals, particularly the deinking agent, are also concentrated, the foaming property during the flotation step becomes extremely large, which causes a great decrease in the yield. Also, as a cause of rising foaming,
Concentration of inorganic salts such as calcium ions in fillers cannot be ignored. In any case, white water circulation will reduce the deinking pulp performance and deinking efficiency. Despite these circumstances, surprisingly, almost no studies have been made on deinking agents or systems that can maintain deinking performance even in the white water circulation system. The company operates with new water diluted or additional wastewater treatment equipment.

[0004]

In the deinking process, it is desirable to circulate and reuse white water from the viewpoint of resources and work, but the white water circulation is reduced without lowering the whiteness and yield. It is difficult to do so, and a solution is needed.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present inventors have developed a deinking method capable of reducing the remaining ink area ratio without reducing the whiteness while maintaining an appropriate yield even in a white water circulation system. When the system was studied in depth, the presence of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound in the flotation process using treated water containing white water provided the same performance as that of a conventional deinking method. It was confirmed that there was no decrease, but rather that the white water and the remaining ink area ratio improved by positively circulating the use of white water improved the deinking performance, and the present invention was completed.

That is, the present invention relates to a deinking method including a flotation step using treated water containing white water.
A deinking method characterized in that at least a part of the flotation step is performed in the presence of at least one selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound. is there.

[0007] In the deinking method of the present invention, the flotation step is preferably performed using treated water containing white water discharged in the steps after the flotation step. White water discharged in a step before the flotation step, for example, white water discharged in a waste paper disintegration step, contains considerable ink and is not suitable for use in the flotation step.

[0008] The steps after the flotation step include a washing step, a dewatering step, and a paper making step after the flotation step. Generally, the white water discharged in these steps is removed.
50% or more, preferably 70% or more is mixed with fresh water as needed and circulated as treated water in the flotation step.

In the present invention, the white water is circulated at least once, but if it is performed more than three times, the difference from the prior art is remarkable in whiteness and the remaining ink area ratio, which is desirable.

In the present invention, at least a part of the flotation step is carried out in the presence of at least one selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound. These compounds are present in an amount of from 0.001 to 5.0% by weight, in particular from 0.
It is preferably added in an amount of from 05 to 2% by weight.

In the present invention, it is desirable that the pH of the system in the flotation step is set to 4 to 12, preferably 6 to 11, and more preferably 6 to 9. By performing the flotation step at a pH in this range,
A better deinking effect is obtained.

In the present invention, the “system pH” in the flotation step is the pH of the aqueous solution of the water-pulp slurry when performing the flotation treatment. The pH in the flotation step may be adjusted by adding an acid such as hydrochloric acid or sulfuric acid, or a base such as sodium hydroxide or potassium hydroxide as necessary.

Further, for example, the flotation step may be composed of two or more steps. In such a case, the circulation condition of the white water and the pH of the system may be satisfied in at least one flotation step, but preferably in a plurality of steps of flotation, particularly in a step immediately before the first flotation. It is preferred to adjust as described above.

In the deinking method of the present invention, a surfactant is used to remove ink from the raw material waste paper. Specifically, it is preferable to use one or two or more surfactants selected from nonionic surfactants, anionic surfactants and cationic surfactants, and particularly to use nonionic surfactants.

According to the present invention, even if the circulation operation of the white water, which is conventionally considered to reduce the whiteness and the yield, is performed, not only the performance is not reduced but also the whiteness is positively increased by increasing the number of circulations. In addition, the deinking performance seen in the remaining ink area ratio is improved. The mechanism of action is considered as follows. The presence of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound in a flotation system allows fine inks and fillers that could not be removed conventionally to be coagulated to an appropriate size, and that during flotation, Interaction with air bubbles is strengthened, and removal efficiency can be increased. The deinking efficiency is increased by the aggregating action of such fine ink, and the whiteness and the yield can be improved and the remaining ink area ratio can be reduced as compared with the conventional method. Conventionally, fine inks and fillers that could not be removed in the flotation step flow into the system of the subsequent washing step, etc., and white water containing the fine ink etc. was further circulated and used for flotation as described above. In the present invention, the removal rate of fine ink and the like in the flotation step is high, so that the whiteness is improved even in a system in which white water is circulated, and there is no increase in the foaming amount due to the concentration of the filler, so that a good yield is maintained. it can. As described above, in the deinking method of the present invention, even when white water circulating water is used, deinking efficiency equivalent to the use of fresh water can be exhibited. Also, the reason why the effect is increased by actively using white water is not necessarily specified, but it is thought that cationic compounds, amines, acid salts of amines and amphoteric compounds are accumulated in the white water circulating water. .

In the deinking method of the present invention, at least one selected from the group consisting of amines, amine acid salts, amphoteric compounds and cationic compounds is present in the system during flotation. Specific examples of these compounds include the following.

<Cationic Compound> The cationic compound includes compounds represented by the following formulas (a ₁ ) to (e ₁ ) and
(f ₁ ) to (j ₁ ), having a cationic nitrogen content of 0.01
~ 35% by weight, and the weight average molecular weight is 2,000 ~ 3,
It is preferably selected from the group consisting of 000,000 cationic polymers. Particularly preferred is a cationic compound represented by the following formula (a ₁ ).

[0018]

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In the formulas (a ₁ ) to (e ₁ ), R ₁ and R
₂ are the same or different and each have 1 carbon atom
0 to 24 alkyl, alkenyl or β-hydroxyalkyl groups, wherein R ₃ , R ₄ and R ₅ are the same or different from each other and each have an alkyl or hydroxyalkyl group having 1 to 8 carbon atoms, a benzyl group, Or the formula:-
A group represented by (AO) _n -Z (where AO is an oxyalkylene group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and n is an integer of 1 to 50) And
R ₆ is alkyl, alkenyl or β having 8 to 36 carbon atoms.
- a hydroxyalkyl group, X ^- is a counterion, Y is alkyl having 8 to 36 carbon atoms, alkenyl or β- hydroxyalkyl group of the formula: R ₆ COOCH ₂ - (wherein, R ₆ is defined Is a group represented by
A group represented by the formula: R ₆ CONHCH ₂ — (where R ₆ is as defined above) or a group represented by the formula: R ₆ OCH ₂ — (where R ₆ is as defined above) It is a group to be performed.

[0020]

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In equations (f ₁ ) to (j ₁ ), R ₁ ,
_{R 2, R 3, R 6} , R 7, R 8 and R ₉ are the same or different from each other, respectively, an alkyl group or an alkenyl group having a carbon number of 2 to 24 1 to 24 carbon atoms, R ₄ And R ₅ are the same or different and are each a hydrogen atom or a methyl group; X ⁻ and W ⁻ are the same or different and are each a counter ion; and Y and Z are
Are the same or different and are each O or NH
AO is an oxyalkylene group having 2 to 4 carbon atoms, p and q are the same or different and are each an integer of 1 to 10, and r is an integer of 0 to 10. , L, m and n are each a positive number such that the weight average molecular weight of the polymer is a value in the range of 2,000 to 3,000,000.

<Amine and amine acid salt> The amine and amine acid salt are represented by the following formulas (a ₂ ) to (h ₂ ) and the following formulas (i ₂ ) to (l ₂ ): Amino nitrogen content is 0.0
1 to 35% by weight and a weight average molecular weight of 2,000 to
Preferably it is selected from the group consisting of 3,000,000 polymers. Particularly preferably, the following formula (a ₂ ) or (b
₂ ) An amine or an acid salt of an amine represented by ₂ ).

[0023]

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In the formulas (a ₂ ) to (h ₂ ), R ₁ is an alkyl, alkenyl or β-hydroxyalkyl group having 8 to 36 carbon atoms, and R ₂ and R ₃ are the same or different from each other. A hydrogen atom, an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms,
A represents an inorganic or organic acid; AO is an oxyalkylene group having 2 to 4 carbon atoms;
+ M is 0 or a positive integer under the condition that + m is an integer of 1 to 300, and W ₁ , W ₂ , W ₃ and W ₄ are the same or different from each other, and are each a hydrogen atom or a carbon atom having 1 to 300;
24 alkyl groups.

[0025]

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In the formulas (i ₂ ) to (l ₂ ), R ₁ is an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms, and R ₂ , R ₃ and R ₆ are each other the same or different and each represents a hydrogen atom, an alkyl group or an alkenyl group having a carbon number of 2 to 24 1 to 24 carbon atoms, R ₄
And R ₅ are the same or different and are each a hydrogen atom or a methyl group, HA is an inorganic or organic acid, Y is O or NH, and p is an integer of 1 to 10. And l, m and n are each a positive number such that the weight average molecular weight of the polymer is in the range of 2,000 to 3,000,000. In the case of an amine acid salt, HA is preferably an organic acid, particularly preferably acetic acid.

<Amphoteric Compound> The amphoteric compound has the following formula (a)
₃ ) to compounds represented by (j ₃ ), phospholipid (k ₃ ), protein
(l ₃ ) and a group of amphoteric polymers represented by the following formulas (m ₃ ) and (n ₃ ), having a cationic nitrogen content of 0.01 to 35% by weight and a weight average molecular weight of 2,000 to 3,000,000. It is preferable to be selected from Particularly preferred are amphoteric compounds represented by the following formula (b ₃ ).

[0028]

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In the equations (a ₃ ) to (j ₃ ), R ₁ , R ₂
And R ₃ are the same or different and are an alkyl group having 1 to 24 carbon atoms or an alkenyl group having 2 to 24 carbon atoms, respectively, and R ₄ is an alkyl group having 8 to 36 carbon atoms, alkenyl or β-. A hydroxyalkyl group, wherein M is
A hydrogen atom, an alkali metal atom, a モ ル mole of an alkaline earth metal atom or an ammonium group, and Y ₁ has the formula: R ₅
NHCH ₂ CH ₂ — (where R ₅ is an alkyl group having 1 to 36 carbon atoms, or an alkenyl or hydroxyalkyl group having 2 to 36 carbon atoms),
Y ₂ is a hydrogen atom or a group represented by the formula: R ₅ NHCH ₂ CH ₂ — (where R ₅ is as defined above), and Z ₁ is —CH ₂ COOM (where, M is the same as defined above), and Z ₂ is a hydrogen atom or a group represented by the formula: —CH ₂ COOM (where M is as defined above). .

[0030]

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In the formulas (m ₃ ) and (n ₃ ), R ₁ , R ₂
And R ₃ are the same or different and are each a hydrogen atom, an alkyl group having 1 to 24 carbon atoms or
R ₄ and R ₅ are the same or different from each other and are each a hydrogen atom or a methyl group, and M is a hydrogen atom, an alkali metal atom, and モ ル mole of an alkaline earth metal. an atom or an ammonium group, X ^-
Is a counter ion, Y is O or NH, and p is 1
And m and n are each a positive number such that the weight average molecular weight of the polymer is in the range of 2,000 to 3,000,000.

Among the cationic compound, amine, amine acid salt and amphoteric compound, it is particularly preferable to use amine and amine acid salt.

At least one selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound may be added in any step capable of adjusting the concentration during flotation. It may be added in one step before flotation, for example, in a defibration step or a bleaching step, may be added immediately before or during flotation (for example, at the beginning of the flotation step), It may be added in a later washing step and circulated together with the white water. Preferably, at least one selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound is added immediately before flotation, in a flotation system or in circulating water, and particularly, when the pH of the slurry is 4 to 9 After adjusting to the value, it is preferable to add to the slurry.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, in the step of removing ink, at least one surfactant is used for removing the ink. As the surfactant, a surfactant conventionally known as a deinking agent can be used, but a cationic surfactant, an anionic surfactant, and a nonionic surfactant are preferable, and a nonionic surfactant is particularly preferable. Agent. As the nonionic surfactant, one or more kinds selected from the following (A) to (D) are preferable.

<Nonionic surfactant (A): Reaction product obtained by adding alkylene oxide to a mixture of fat and oil and alcohol> Nonionic surfactant (A) is a mixture of fat and oil, monovalent or polyvalent. It is an alkylene oxide adduct of a mixture with an alcohol. Alkylene oxide is added to the above mixture in an average of 5 to 300 per mole of the mixture.
Moles, preferably 20 to 150 moles.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide, and they may be used alone or in the form of a mixture of two or more thereof.

The mixing ratio of fats and oils to alcohol is 1
/0.1 to 1/6 is preferred, and 1 / 0.3 to 1/3 is particularly preferred. When the ratio is within the above range, the peeling of the ink is sufficiently performed, so that the regenerated pulp having a good appearance can be obtained.

Examples of oils and fats as raw materials of the nonionic surfactant (A) include vegetable oils such as coconut oil, palm oil, olive oil, soybean oil, rapeseed oil, linseed oil, and animal oils such as lard, beef tallow, bone oil and the like. , Fish oil, their hardened and semi-hardened oils, and the recovered oils obtained in the purification process of these oils and fats. Particularly preferred are coconut oil, palm oil and tallow.

Examples of the monohydric alcohol as a raw material of the nonionic surfactant (A) include those having an alkyl or alkenyl portion having 8 to 24 carbon atoms, and those having an alkyl portion having 6 to 14 carbon atoms. Those having an alkylphenyl moiety are included. Preferably 12 to 18 carbon atoms
Having an alkyl moiety of

Examples of the polyhydric alcohol as a raw material of the nonionic surfactant (A) include ethylene glycol, propylene glycol, glycerin, trimethylolpropane and the like.

<Nonionic surfactant (B): Formula: RCO
Compound represented by O (AO) _m R ′> In the above formula, R represents an alkyl or alkenyl group having 7 to 23 carbon atoms;
Is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, 2 carbon atoms
Represents an alkenyl group having 2 to 22 carbon atoms or an acyl group having 2 to 22 carbon atoms, preferably hydrogen, AO represents an oxyalkylene group having 2 to 4 carbon atoms, and m is an integer of 1 or more. A
The average number of added moles of O is preferably from 5 to 300 moles. Further, it is preferable to use ethylene oxide and propylene oxide as AO at a molar ratio of ethylene oxide to propylene oxide of 1/5 to 5/1.
Among the nonionic surfactants (B), those having the carbon number of the alkyl or alkenyl group represented by R, particularly those having 11 to 23 carbon atoms, are preferable.

<Nonionic surfactant (C): Formula: RO
Compound represented by (AO) _n H> In the above formula, R represents an alkyl or alkenyl group having 8 to 24 carbon atoms, and AO is
It represents an oxyalkylene group having 2 to 4 carbon atoms, and n is an integer of 1 or more. The average number of moles of AO added is preferably from 5 to 300 moles, more preferably from 7 to 150 moles. Further, it is preferable to use ethylene oxide and propylene oxide as AO at a molar ratio of ethylene oxide to propylene oxide of 1/5 to 5/1.

<Nonionic surfactant (D): a reaction product obtained by adding an alkylene oxide to a polyvalent carboxylic acid or its acid anhydride, or a polyvalent carboxylic acid or its acid anhydride and an alcohol The reaction product obtained by adding an alkylene oxide to a mixture of a nonionic surfactant (D)> is produced using a polycarboxylic acid or its anhydride (I) and an alcohol (II). You. At that time, the compounds (I) and (II) are converted from (I) to (II)
Is preferably used at a molar ratio of 1 / 0.02 to 5, particularly preferably 1 / 0.1 to 3.

As the anionic surfactant, a higher fatty acid salt, an alkyl sulfonate, an alkylbenzene sulfonate, an alkyl sulfate, an alkyl ether sulfate and the like are preferably used. As the cationic surfactant, a quaternary ammonium salt can be used, and a mono-long chain alkyl type quaternary ammonium salt is particularly preferable.

The surfactant may be added to any step of the deinking method. However, it is usually added to the pulping step. The amount of addition is not particularly limited, but is preferably 0.01 to 10% by weight, particularly 0.05 to 3% by weight based on the raw waste paper. Of course, the above nonionic surfactant (A) ~
Known deinking agents other than (D) can be used in combination therewith.

In the deinking method of the present invention, at least a part of the flotation step is carried out together with at least one selected from the group consisting of the above-mentioned cationic compounds, amines, acid salts of amines and amphoteric compounds. It is preferable to carry out the reaction in the presence of the organic acid represented by the general formula (I) or ions thereof in terms of improving whiteness and reducing the remaining ink area ratio. X ₁ —O— (AO) _n —X ₂ (I) wherein X ₁ is an alkyl or alkenyl group having 1 to 24 carbon atoms, —H, —CH ₂ COOH, —SO ₃ H or —
PO ₃ H ₂ , X ₂ is —CH ₂ COOH, —SO ₃ H
Or a -PO ₃ H _2, AO is an alkylene oxide group having 2 to 4 carbon atoms, n is the number of 1 to 200. The organic acid (I) may be present in any form of an acid or an ion, and may be a counter ion of a cationic compound.
It can be used as (X ⁻ ) or as an organic acid (HA) used to form an acid salt of an amine. In the former case, the target compound can be obtained by replacing the counter ion of the cationic compound with the residue of an organic acid by a known ion exchange method. In the general formula (I), X ₁ and X ₂ represent —CH ₂
COOH is preferable, and AO is preferably an alkylene oxide group having 2 to 3 carbon atoms, that is, ethylene oxide and propylene oxide, and particularly preferably ethylene oxide. It is also preferable to use ethylene oxide and propylene oxide in block or random addition. Further, n is more preferably a number of 1 to 50.

Organic acid (I) or its ion [(B)
Component] is at least one compound selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound [Component (A)] in a molar ratio with the component (B) (as an acid) / ( The component (A) is preferably used in a ratio of 10/1 to 1/10, and more preferably the component (B) / (A).
Component = 2/1 to 1/2.

In the present invention, the component (A) and the component (B) are (A) + (B) = 0.005 to 10.0% by weight, based on the weight of the waste paper, in total. In particular, it is preferable to add 0.01 to 2.0% by weight.

[0048] The deinking method of the present invention comprises at least a step of removing ink from raw waste paper, a step of removing the separated ink by a flotation method, a step of washing the deinked pulp slurry, and a washing step. Dewatering the pulp slurry, wherein at least one of a surfactant, preferably a nonionic surfactant as described above, is used for ink removal, and white water is used in the flotation step. In order to use, the white water discharged from the steps after the flotation step is circulated to the treated water of the flotation step, and at least a part of the flotation step is a cationic compound exemplified above, an amine, and an amine. The method is carried out in the presence of at least one selected from the group consisting of acid salts and amphoteric compounds.

[0049]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Raw material recovered from the city (newspaper / flyer = 70/30) was cut into 5 cm x 5 cm pieces, and a certain amount was put into a tabletop disintegrator, into which hot water and 1 weight of sodium hydroxide were added. % (Based on raw materials), 3% by weight of sodium silicate (based on raw materials), 3% by weight of 30% hydrogen peroxide solution (based on raw materials), stearyl alcohol E as a deinking agent
O20 mole PO15 mole block adduct (average number of moles added)
0.3% by weight (based on raw materials), pulp concentration 5% by weight, 40%
Disintegrated at 10 ° C for 10 minutes. After the obtained pulp slurry was aged at 40 ° C. for 60 minutes, washed pulp was added to dilute the pulp concentration to 1%, and the pH was adjusted as shown in Table 1 using sulfuric acid or an aqueous sodium hydroxide solution. , And the following amine compound (II-b-1) was added at the concentration shown in Table 1 (based on the raw material),
A flotation treatment was performed at 40 ° C. for 10 minutes. In addition, in the comparative example, the addition of the amine compound was not performed. After the flotation treatment, a pulp sheet is prepared with a tapping machine,
After pressurizing at 5 kgf / cm ² , air drying was performed, and whiteness and remaining ink amount were measured. Here, the whiteness of the pulp sheet is measured with a colorimeter and the residual ink amount is determined by measuring the residual ink area ratio of the pulp sheet obtained from the pulp slurry (after flotation) by an image analyzer (magnification). : × 100). A 1% improvement in pulp sheet whiteness and a 0.1% decrease in residual ink area percentage can be visually perceived as a significant improvement in pulp sheet quality. In addition, the pulp yield was calculated based on the absolute dry weight of the pulp contained in the pulp slurry before flotation and the absolute dry weight of the pulp contained in the flotation reject [that is, [(included in the pulp slurry before flotation). Calculated from the absolute dry weight of the pulp that was removed)-(the absolute dry weight of the pulp contained in the flotation reject)] x 100 / (the absolute dry weight of the pulp contained in the pulp slurry before flotation)] Was. Table 1 shows the results.

The washing white water used for the pulp dilution in the flotation is firstly used with fresh water (the 0th time), then dewatered so that the pulp slurry concentration after the flotation becomes 10%, and discharged at that time. A mixture of 80% fresh water and 20% fresh water was used as washing white water. The number of circulations in the table indicates the number of circulations of the white water obtained by this dehydration (the same applies to the following examples).

[0052]

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[0053]

[Table 1]

The test examples 1 to 4 in the table are the methods according to the present invention, and in each test example, the white water circulation number "0" is a control (the same applies to the following examples).

Example 2 Raw material recovered from the city (newspaper / flyer = 70/30) was cut into 5 cm × 5 cm pieces, and a certain amount was put into a tabletop disintegrator, into which hot water and 1 weight of sodium hydroxide were added. % (Based on raw material), 3% by weight of sodium silicate (based on raw material), 30% by weight of 30% hydrogen peroxide solution (based on raw material), EO15 mole of stearic acid PO10 mole random addition product as deinking agent (average number of moles added) 0.3% by weight (based on raw material) was added, and pulp concentration was 25% by weight, and defibration was performed at 40 ° C for 10 minutes. The obtained pulp slurry was aged at 40 ° C. for 60 minutes, and then washed white water was added to dilute the pulp concentration to 1%.
The pH was adjusted as shown in (1) and the cationic compound (I)
-A-1) was added at 0.3% by weight (based on waste paper) and the temperature was increased to 40 ° C.
For 10 minutes. In addition, in the comparative example, the cationic compound (Ia-1) was not added. Thereafter, a pulp sheet was prepared in the same manner as in Example 1, and the yield, whiteness, and residual ink amount were measured in the same manner as in Example 1. Table 2 shows the results.

[0056]

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[0057]

[Table 2]

Example 3 Raw material recovered from the market (newspaper / flyer = 70/30) was cut into 5 cm × 5 cm pieces, and a certain amount was put into a tabletop disintegrator, into which hot water and 1 weight of sodium hydroxide were added. % (Based on raw material), 3% by weight of sodium silicate (based on raw material), 3% by weight of 30% hydrogen peroxide solution (based on raw material), tallow / glycerin (1:
0.5 mol ratio) EO 75 mol PO 15 mol block adduct (average addition mol number) 0.35% by weight (based on raw material) was added, and pulp concentration was 5% by weight, and the mixture was disintegrated at 40 ° C for 10 minutes. After the obtained pulp slurry was aged at 40 ° C. for 60 minutes, washed pulp was added to dilute the pulp concentration to 1%, and the pH was adjusted using sulfuric acid or sodium hydroxide aqueous solution as shown in Table 3. 0.1% by weight of amphoteric surfactant (III-b-1) (based on raw material)
After the addition, a flotation treatment was performed at 40 ° C. for 10 minutes. In addition, in the comparative example, the addition of the amphoteric compound (III-b-1) was not performed. Thereafter, a pulp sheet was prepared in the same manner as in Example 1, and the yield, whiteness, and residual ink amount were measured in the same manner as in Example 1. Table 3 shows the results.

[0059]

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[0060]

[Table 3]

Example 4 Raw material recovered from the city (newspaper / flyer = 70/30) was cut into 5 cm × 5 cm pieces, and a certain amount was put into a tabletop disintegrator, into which hot water and 1 weight of sodium hydroxide were added. % (Based on raw materials), 3% by weight of sodium silicate (based on raw materials), 3% by weight of 30% hydrogen peroxide solution (based on raw materials), stearyl alcohol E as a deinking agent
O30 mole PO30 mole random adduct (average number of moles added)
0.35% by weight (based on raw materials) was added, and the pulp concentration was 5% by weight,
Disintegrated at 10 ° C for 10 minutes. After the obtained pulp slurry was aged at 40 ° C. for 60 minutes, washed pulp was added to dilute the pulp concentration to 1%, and the pH was adjusted as shown in Table 4 using sulfuric acid or an aqueous sodium hydroxide solution. Further, a mixture of the following cationic compounds, amines or amphoteric compounds (shown as the component (A) in Table 4) and the following organic acids in equimolar amounts in the combination shown in Table 4 was 0.2% by weight (based on the raw material). Waste paper) and subjected to a flotation treatment at 40 ° C. for 10 minutes.
In the cation compound, the counter ion was replaced with an organic acid shown in Table 4 by an ion exchange method. In Comparative Examples, addition of a cationic compound, an amine or an acid salt of an amine, and an organic acid was not performed. Thereafter, a pulp sheet was prepared in the same manner as in Example 1, and the yield, whiteness, and residual ink amount were measured in the same manner as in Example 1. Table 4 shows the results.

[0062]

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[0063]

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[0064]

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◎ Organic acid α CH ₃ COOH ◎ Organic acid β-1 HOOC--CH ₂ --O-(CH ₂ CH
₂ O) ₆ -CH ₂ COOH

[0066]

[Table 4]

Example 5 Raw material recovered from the market (newspaper / flyer = 70/30) was cut into 5 cm × 5 cm pieces, and a certain amount was placed in a tabletop disintegrator, into which hot water and 1 weight of sodium hydroxide were added. % (Based on raw material), 3% by weight of sodium silicate (based on raw material), 3% by weight of 30% hydrogen peroxide solution (based on raw material), EO 20 mole of stearic acid 5 moles of PO as a deinking agent Random adduct (average number of moles added) 0.3% by weight (based on raw material) was added, and pulp concentration was 25% by weight, and defibration was performed at 40 ° C for 10 minutes. The obtained pulp slurry was aged at 40 ° C. for 60 minutes, and then washed white water was added to dilute the pulp concentration to 1%.
The pH was adjusted as shown in (1) and the amine compound II-a-1 was further added.
(Same as used in Example 4) and an organic acid shown below in an equimolar mixture in the combination shown in Table 5 were added in an amount of 0.2% by weight (based on waste paper), followed by flotation at 40 ° C. for 10 minutes. Processing was performed. Incidentally, the comparative example was prepared using the amine compound II-
a-1 and the organic acid were not added. Thereafter, a pulp sheet was prepared in the same manner as in Example 1, and the yield, whiteness, and residual ink amount were measured in the same manner as in Example 1. Table 5 shows the results.
Shown in

Organic acid α CH ₃ COOH Organic acid β-2 HOOC-CH ₂ -O- (EO) _10- (PO) _3- (EO) _10-
CH ₂ COOH [EO: —CH ₂ —CH ₂ —O—, PO: —CH (CH ₃ )
-CH ₂ -O-] ◎ Organic acid β-3 HO ₃ S-O- (CH ₂ CH ₂ O) ₈ -SO
₃ H ◎ organic acid _{β-4 HO- (CH 2 CH} 2 O) 10 -PO 3 H 2 ◎ organic acid ^{γ-1 R 1 -O- (CH} 2 CH 2 O) 50 -CH 2 COOH [R ^1:
C ₁₈ alkyl group]

[0069]

[Table 5]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-241084 (JP, A) JP-A-4-163386 (JP, A) JP-A-52-31563 (JP, A) JP-A-59-1984 53532 (JP, A) Tokuhyo Hei 5-500690 (JP, A) Tokuhyo Hei 8-505444 (JP, A) Reizaburo Oe et al., Paper and pulp Papermaking Chemistry and Technology Volume 1, Volume 2, Chugai Industry Research Committee, December 5, 1986, pp. 570-572 (58) Fields surveyed (Int. Cl. ⁷ , DB name) D21C 5/02

Claims (7)

(57) [Claims] 1. A deinking method including a flotation step using treated water containing white water, wherein at least a part of the flotation step is performed by using a cation having the following formula (a ₁ ):
An amine compound represented by the following formula (a ₂ );
₂ ) an acid salt of an amine represented by the following formula (b ₃ ):
A deinking method which is performed in the presence of at least one selected from the group consisting of amphoteric compounds . Embedded image [In the formula (a ₁ ), R ₁ and R ₂ are the same or
Differently, respectively, alkyl having 10 to 24 carbon atoms,
Alkenyl or β- hydroxyalkyl group, R ₃
And R ₄ are the same or different from each other;
An alkyl or hydroxyalkyl group having a prime number of 1 to 8,
A benzyl group, or a formula:-(AO) _n -Z (where AO is
An oxyalkylene group having 2 to 4 carbon atoms, X ^- is Taii
Is on. [Chemical formula 2] [In the formulas (a ₂ ) to (b ₂ ), R ₁ has 8 to 3 carbon atoms.
6 alkyl, alkenyl or β-hydroxyalkyl
R ₂ and R ₃ are the same or different from each other,
A hydrogen atom, an alkyl group having 1 to 24 carbon atoms or
HA is an alkenyl group having 2 to 24 carbon atoms, and HA is an inorganic or
Represents an organic acid, and AO represents an oxyalkyl group having 2 to 4 carbon atoms.
It is a len group. [Chemical formula 3] [In the formula (b ₃ ), R ₁ , R ₂ and R ₃ are the same or
Are different and each is an alkyl group having 1 to 24 carbon atoms
Or it is a C2-C24 alkenyl group. ] 2. A deinking method according to claim 1 Symbol placing comprising the step of circulating more than 50% of the white water. 3. The deinking method according to claim 2 , wherein the white water is circulated to the flotation system immediately before the flotation step. 4. The method of claim 2 in which the circulating operation of the white water conducted over three times
Or the deinking method described in 3 . 5. The deinking method according to claim 1, wherein the flotation step is performed in a pH range of 4 to 12. 6. any one deinking method according to claim 1-5 using at least one surfactant for ink stripping. 7. At least one selected from the group consisting of a cationic compound, an amine, an acid salt of an amine and an amphoteric compound.
The deinking method according to any one of claims 1 to 6 , wherein an organic acid represented by the following general formula (I) or an ion thereof is present together with the seed. X ₁ —O— (AO) _n —X ₂ (I) wherein X ₁ is an alkyl or alkenyl group having 1 to 24 carbon atoms, —H, —CH ₂ COOH, —SO ₃ H or —
PO ₃ H ₂ , X ₂ is —CH ₂ COOH, —SO ₃ H or —PO ₃ H ₂ , AO is an alkylene oxide group having 2 to 4 carbon atoms, and n is a number of 1 to 200. is there. ]