JPH11222788A - Deinking agent for recycled paper - Google Patents

Abstract

(57) [Summary] [Problem] Regardless of the type of used paper, excellent removability of ink and removability of detached ink, high yield of recycled pulp, and as a result, high quality pulp with high whiteness can be obtained. Provide a deinking agent for recycling waste paper that can be obtained efficiently. A compound represented by the following general formula (1) [Component (A)] and a compound represented by the following general formula (2) [Component (B)] are mixed in a weight ratio [(A) / (B)]
(A) / (B) = a deinking agent for recycling waste paper, which is contained at a ratio of 91/9 to 99/1. Embedded image Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking agent used for recycling used printing paper such as newspapers, magazines, flyers, high-quality paper, information recording paper, imitation paper, and the like. The present invention relates to a deinking agent for waste paper recycling (hereinafter, referred to as a "deinking agent") capable of producing high-whiteness recycled pulp at a high pulp yield when deinking is performed by a rotation method, a washing method, or the like.

[0002]

2. Description of the Related Art Conventionally, deinking agents used in the recycling of used printed paper such as newspapers, magazines, flyers, information recording paper, imitation paper and the like have been improved in deinking properties with the diversification of used paper. . For example, particularly recently, the effective use of waste paper has increased due to the shortage of pulp resources and the soaring price thereof, and the advanced use of deinked recycled pulp has been carried out. Further, in recent waste paper, printing methods and printing ink components have changed due to the development of printing technology, and the situation has become more severe in deinking waste paper.

[0003] Under such circumstances, an apparatus has been improved to promote deinking, but a deinking separation method using a chemical has been more widely used in a used paper recycling process. The chemicals include alkaline agents such as caustic soda, sodium silicate, sodium carbonate and sodium phosphate, bleaching agents such as hydrogen peroxide, hyposulfite, hypochlorite, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid ( A blend of an auxiliary such as a sequestering agent such as DTPA) and a deinking agent is used. Examples of the deinking agent include higher fatty acids, soaps, sodium salts of alkyl benzene sulfonic acids, sodium salts of higher alcohol sulfates, sodium salts of α-olefin sulfonate dialkyl sulfosuccinates,
Anionic surfactants such as ethoxylated higher alcohol sulfate ammonium salts and fatty acid Na salts, and nonionic interfaces which are ethylene oxide and propylene oxide added to starting materials such as higher alcohols, fatty acids and alkylphenols, or ethylene oxide only added. The activator has been used alone or as a combination of two or more. Further, from the viewpoint of effective use of waste paper, the performance of increasing the yield of recycled pulp is required of these deinking agents as an accompanying performance.

[0004]

However, such a conventional deinking agent is disclosed, for example, in JP-A-51-8.
Alkylbenzene sulfonates, higher alcohol sulfates, ethylene oxide adducts of higher alcohols or alkyl phenols, and dialkyl sulfosuccinates described in JP-B-56-17476, which are found in the deinking composition described in JP-A-4905. Although the ink has a good performance with respect to the dispersibility of the ink to some extent, it has a disadvantage that the whiteness is insufficient due to the lack of the ability to collect the detached ink. Further, it is known that the fatty acid Na salt soap used in Japanese Patent Publication No. 61-1556 increases the detachable ink removal property and improves the whiteness in flotation in the used paper recycling step. There is a disadvantage that the deinking effect is reduced when used alone or in hard water.

Further, Japanese Patent Application Laid-Open No. Sho 53-31804,
JP-A-55-51891, JP-A-55-5189
JP-A-58-79795 and JP-A-56-79795 show random addition products of higher alcohols, propylene oxide and ethylene oxide, respectively.
No. 9696 discloses a random addition product of propylene oxide and ethylene oxide of higher fatty acids. All of these chemicals are used for the deinking of old newspapers, but have the drawback that high whiteness pulp cannot be obtained due to lack of ink releasability and collection of the released ink. I have.

Further, Japanese Patent Publication No. 51-13762, Japanese Patent Publication No. 4-80153, and Japanese Patent Application Laid-Open No. Sho 62-177291.
Japanese Patent Publication No. 6-65792 discloses a deinking agent using an alkylene oxide adduct of a higher alcohol and a higher fatty acid in combination. However, the above-mentioned higher fatty acids lack ink releasability, and thus have a drawback that recycled pulp having high whiteness cannot be obtained.

[0007] JP-B-4-80151, JP-A-61-41386, and JP-A-4-361681.
In Japanese Patent Application Publication No. JP-A-2002-264, a deinking agent containing a random addition product of an alkylene oxide of a higher alcohol as a main component is disclosed. However, these chemicals have a drawback that the loss of pulp is increased and the yield of recycled pulp is reduced due to the high foamability of a high-bubble type floatator that has been frequently used in recent years.

Japanese Patent Application Laid-Open No. 4-361681 and Japanese Patent No. 2593766 disclose a compound in which block addition and random addition of alkylene oxide of higher alcohol are mixed.
No. 934, Japanese Patent No. 2,577,691, Japanese Patent Application Laid-Open No. 7-3681, Japanese Patent Application Laid-Open No. 7-324292, and Japanese Patent Application Laid-Open No. 8-284087, add three or more alkylene oxide block adducts to a higher alcohol. Compounds characterized by the following are disclosed. However, these compounds still have the drawback that the ink-collecting properties are still insufficient, a large amount of fine ink remains, and the whiteness of the recycled pulp decreases.

On the other hand, in recent waste paper, offset printing paper and information recording paper as well as conventional newspapers and magazines are being recycled as waste paper. The waste paper mixed with these uses a thermosetting vehicle or toner ink, so that the above-described deinking agent does not provide a sufficient deinking effect and efficiently obtains high-quality recycled paper. In addition, there is a demand for a high-performance deinking agent.

[0010] The present invention has been made in view of such circumstances, and regardless of the type of printed waste paper, it has excellent ink releasability and removable ink removability, and the recycled pulp yield is high. It is an object of the present invention to provide a deinking agent from which high-quality pulp with high whiteness is obtained with high yield.

[0011]

To achieve the above object, the deinking agent of the present invention comprises the following components (A) and (B)
The components are expressed as (A) / (B) in a weight ratio [(A) / (B)].
= 91/9 to 99/1.

(A) A compound represented by the following general formula (1).

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(B) A compound represented by the following general formula (2).

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That is, the present inventor has conducted various studies on various compounds in order to obtain a deinking agent which has a small amount of residual ink and a high yield of recycled pulp when recycling waste paper. As a result, as a deinking agent, ethylene oxide and butylene oxide were added to hydrophobic groups having a specific number of carbon atoms to form propylene oxide-ethylene oxide-
Properly added block in the order of propylene oxide,
If a mixture of two kinds of compounds having a special molecular structure and a medium molecular weight (the above-mentioned components (A) and (B)) is used in a specific ratio, it can be used for offset printing waste paper or information recording. It has been found that even the ink which is difficult to peel off from waste paper has an excellent ability to promote the desorption from the pulp fiber by the function of the above-mentioned hydrophobic group and to separate it into a liquid. Further, as described above, since the compound constituting the mixture is a compound obtained by appropriately adding ethylene oxide and propylene oxide to a long-chain alcohol, the compound has a moderate ink cohesion in a flotator. And also has a moderate foam suppressing power. These ink cohesive forces and foam suppressing properties not only match the high-bubble type floatator that has been introduced in recent years, but also have the effect of suppressing foaming caused by increased magazine waste paper (coated paper). I also found out. Further, the present inventors have found that a high-quality pulp having high whiteness can be obtained because the detachable ink has a strong ability to collect the detached ink in the floatator.

When the above two compounds are used in combination at a specific ratio and further used together with a higher fatty acid (component (C)) having a specific carbon number, the ink aggregates to form large ink particles, In the flotator, the effect that the coagulated ink can be efficiently removed can be obtained.

Furthermore, the weight ratio of the total amount (α) of the components (A) and (B) to the component (C) [(α) /
When (C)] is set to a specific ratio, the ink cohesive force is appropriately adjusted, and a large number of ink aggregates having a particle size that can be easily removed by the flotator are formed. By this effect, an effect is obtained that the amount of ink remaining in the post-flotation step is significantly reduced.

[0017]

Next, embodiments of the present invention will be described in detail.

The deinking agent of the present invention can be obtained by using the above specific compound.

One of the above specific compounds is a compound (component A) represented by the following general formula (1), which is obtained by adding an alkylene oxide to a long-chain alcohol having a specific carbon number. is there.

[0020]

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In the above formula (1), R ₁ has 16 carbon atoms.
An alkyl group having 20 to 20 carbon atoms, particularly preferably an alkyl group having 18 carbon atoms, from the viewpoint that ink releasability and bubble characteristics are more excellent. The number of repetitions l ₁ is 3
An integer of from 8 to 8, and particularly preferably l ₁ is 6. Further, the number of repetitions m ₁ is an integer of 15 to 25, more preferably m ₁ is an integer of 20 to 25, and particularly preferably m
₁ is 25. And the number of repetitions n ₁ is 10 to 20
And more preferably n ₁ is an integer of 13 to 18,
Particularly preferably, n ₁ is 17.

More specifically, the compound represented by the above formula (1) is obtained by block-adding propylene oxide, ethylene oxide and propylene oxide in this order to a higher alcohol having an average of 16 to 20 carbon atoms. Specific examples of the higher alcohol include cetyl alcohol, 2-hexyldecanol, stearyl alcohol, oleyl alcohol, and 2-octyldodecanol. Further, a higher alcohol having 18 carbon atoms is particularly preferred from the viewpoint that ink releasability and bubble properties are further improved, and specific examples include stearyl alcohol and oleyl alcohol.

In the present invention, in order to obtain an effective deinking agent, the order of the above-mentioned addition reaction of propylene oxide, ethylene oxide and propylene oxide is important with respect to the formula (1), as described above. It is necessary to take a block addition form so as to be in the above order. In order to be used as a deinking agent, it is necessary to be water-soluble, and for this purpose, of the three block additions, the second alkylene oxide, that is, the central alkylene oxide is ethylene oxide. There is a need. This ethylene oxide amount is 20 to 6 in the total alkylene oxide.
It is preferable to set so as to be in the range of 0 wt%. Particularly preferably, it is 40 to 50% by weight.

The compound represented by the above general formula (1) is prepared by first adding propylene oxide to a higher alcohol having an average carbon number in the range of 16 to 20, adding ethylene oxide to the terminal hydroxyl group, and then adding propylene oxide. It can be manufactured by adding. In such an addition reaction of propylene oxide and alkylene oxide such as ethylene oxide, an appropriate amount of an alkaline substance, an alkali metal hydroxide, a carbonate or the like usually used in these reactions is used.

Another one of the above specific compounds is a compound (component B) represented by the following general formula (2), wherein an alkylene oxide is added to a long-chain alcohol having a specific carbon number. It is added.

[0026]

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In the above formula (2), R ₂ has 22 carbon atoms.
~ 50 alkyl groups, more preferably 3 carbon atoms
An alkyl group having 5 to 45 carbon atoms is particularly preferable because it has a better ink-collecting property and bubble properties.
It is an alkyl group of 0. The number of repetitions l ₂ is 3 to 8
And particularly preferably, l ₂ is 4. Further, the number of repetitions m ₂ is an integer of 15 to 25, more preferably m
₂ is an integer of 20 to 25, and particularly preferably, m ₂ is 2
5 Then, an integer number of repetitions n ₂ is from 10 to 20, more preferably n ₂ is an integer of 13 to 18, particularly preferably n ₂ is 13.

More specifically, the compound represented by the above formula (2) is a compound obtained by adding propylene oxide, ethylene oxide and propylene oxide in this order to a higher alcohol having an average carbon number of 22 to 50. Specific examples of the higher alcohol include tetracosanol, hexacosanol, octacosanol, nonacosanol, myricyl alcohol, melisyl alcohol, rasserol, cellomerisyl alcohol, tetratriacontanol, heptatriacontanol, and tetracosanol. And tetracontanol. Further, a long-chain alcohol having 40 carbon atoms is preferable from the viewpoint that the ink-collecting property and the bubble property are further improved.

In the present invention, in order to obtain an effective deinking agent, the above-mentioned propylene oxide, ethylene oxide and propylene are also used for formula (2) as well as for the compound represented by formula (1) described above. The order of the addition reaction of the oxide is important, and it is necessary to take a block addition form so as to be in the above order. In order to be used as a deinking agent, it must be water-soluble, and for this purpose, as in the general formula (1), of the three block additions, the second alkylene oxide, Part of the alkylene oxide must be ethylene oxide. This amount of ethylene oxide is 20% of the total alkylene oxide.
It is preferable to set so as to fall within the range of 60 to 60% by weight. Particularly preferably, it is 45 to 55% by weight.

The compound represented by the general formula (2) is obtained by first adding propylene oxide to a higher alcohol having an average carbon number in the range of 22 to 50, adding ethylene oxide to the terminal hydroxyl group, and then adding propylene oxide. It can be manufactured by adding. In the addition reaction of the alkylene oxide such as propylene oxide or ethylene oxide, an appropriate amount of a catalyst such as an alkaline substance, an alkali metal hydroxide, or a carbonate commonly used in these reactions is used.

In the deinking agent of the present invention, the compound represented by the above general formula (1) (component A) and the general formula (2)
The combination ratio (A / B) of the compound (B component) represented by
It is necessary to set A / B = 91/9 to 99/1 by weight ratio. Particularly preferably, A / B = 92 / 8-9
The range is 5/5. That is, in the above combined ratio, the ratio of the B component increases (the B component exceeds 9).
In such a case, the coagulation and floating properties of the detached ink and the adjustment of the foaming amount become unstable, so that the detachability deteriorates and high-quality recycled pulp cannot be obtained. Conversely, if the proportion of the component A is too large (the component A exceeds 99), the coagulation and floating properties of the detached fine ink deteriorate, and only a regenerated pulp with much dullness can be obtained.

The deinking agent of the present invention further comprises, in addition to the compounds represented by the above general formulas (1) and (2),
A higher fatty acid having 14 to 22 carbon atoms (component C) may be used. By using the component C, an effect is obtained in which the ink is aggregated to form a large ink particle, and the aggregated ink can be efficiently removed in the flotator.

As the C-component higher fatty acid having 14 to 22 carbon atoms, specifically, palmitic acid, palmitooleic acid, stearic acid, oleic acid, linoleic acid,
Linolenic acid, arachidonic acid, behenic acid and the like.
These may be used alone or in combination of two or more. Above all, stearic acid and oleic acid are particularly preferably used as the component C from the viewpoint that flocculated ink can be efficiently removed by a flotator.

The use ratio of the component C is such that the total amount (α) of the components A and B and the weight ratio [(α) / (C)] of the component C are (α) / (C) = 70/30 ~
It is preferable to set the ratio to 93/7. Particularly preferably, (α) / (C) = 73/27 to 80/20.
It is. That is, when the proportion of the C component exceeds 30 and increases, the whiteness of the recycled pulp tends to decrease due to the decrease in the foaming property of the flotator, and when it is below 7 and too low, the cohesiveness of the fine ink is poor. This is because the recycled pulp tends to increase the residual ink.

Further, the deinking agent of the present invention may optionally contain a conventionally known deinking aid in addition to the above components A, B and C. The amount of these deinking aids is not particularly limited as long as it does not impair the excellent effects of the deinking agent of the present invention.

Examples of the deinking aid include alkali agents such as caustic soda, sodium silicate and sodium sulfate, and bleaching agents such as hydrogen peroxide and sodium hypochlorite. Furthermore, ethylene oxide and propylene oxide addition of known deinking agents such as sodium benzenesulfonate, higher alcohol sulfate, ethoxylated higher alcohol sulfate, fatty acid soap and higher alcohol, higher fatty acid, alkylphenol and other starting materials. Stuff,
Nonionic surfactants such as alkanolamides and compounds obtained by adding ethylene oxide to them, and anionic surfactants may be used. These may be used alone or in combination of two or more. In the present invention, excellent effects are exhibited even when these known deinking agents and deinking aids are used in combination.

The target waste paper to be used with the deinking agent of the present invention is not particularly limited as long as it can be recycled. For example, it is a printed matter such as a newspaper, a magazine, a book, a copied OA waste paper, a flyer, and the like. The present invention can also be applied to printed matter by various printing methods such as letterpress printing, offset printing, and gravure printing.

In general, the deinking operation in the recycling of waste paper follows a waste paper disintegration step, a high-concentration bleaching (aging) step, a flotation step, and a washing step. The deinking agent of the present invention is divided into the above steps and added. Alternatively, the entire amount of the deinking agent may be added to any one of the steps. The total amount of the deinking agent of the present invention added to the above process is 0.0
It is preferable to set within the range of 5 to 1.0% by weight,
Particularly preferably, the addition within the range of 0.1 to 0.2% by weight can provide a sufficient effect as a deinking agent.

Next, examples will be described together with comparative examples.

First, prior to the examples, the following components were prepared. The compounds according to the component A are shown in Table 1 below.

[0041]

[Table 1]

The compounds according to the component B are shown in Table 2 below.

[0043]

[Table 2]

The higher fatty acids according to the component C are shown in Table 3 below.
Shown in

[0045]

[Table 3] Further, the compounds shown in Table 4 below are prepared.

[0046]

[Table 4]

[0047]

Examples 1 to 22, Comparative Examples 1 to 20 The following Tables 5 to 7
The desired deinking agents were prepared by combining the deinking agents as shown in Table 1 and mixing them in the proportions shown in the same table. In addition, component No. in the table. Is the compound No. in Tables 1 to 4. And higher fatty acids No. Represents

[0048]

[Table 5]

[0049]

[Table 6]

[0050]

[Table 7]

Recovered paper was recycled using the deinking agent prepared as described above. That is, 70% by weight of used newspaper used as a raw material (one or two months after printing) and a leaflet 30
% By weight and a pulp disintegrator (JIS P-820).
9), 1.5% by weight of caustic soda, 3% by weight of No. 3 sodium silicate having a concentration of 40%, and a concentration of 30% based on the weight of waste paper
3% by weight of hydrogen peroxide solution and 0.1% by weight of each of the deinking agents shown in Tables 5 to 7 (addition amount was 0.35% by weight only in Comparative Examples 19 and 20). Was adjusted to 5% by weight, and disintegration treatment was performed at about 40 ° C. for 20 minutes. The disintegrated pulp slurry was dehydrated by a high-speed dehydrator to a pulp concentration of 25% by weight. Next, a kneading treatment was performed using a lab kneader (biaxial type, rotation speed 200 rpm). After aging at 60 ° C. for 3 hours, the mixture was diluted with water so that the pulp concentration was 1.0% by weight.
Cl ₂ was added in an amount of 1.0% by weight (vs. waste paper), and a flotation treatment was performed at 35 ° C. for 5 minutes using a flotator. After flotation, 6% pulp slurry
After concentrating to a concentration, water was added to dilute to a 1% concentration and the pH was adjusted to 5. Next, recycled paper having a basis weight of 100 g / m ² was prepared using a tappy standard sheet machine.

The whiteness of the recycled paper thus obtained was measured with a colorimeter (Hunter white according to JIS P-8123). Further, the degree of dullness and the yield of recycled pulp were measured and evaluated according to the following methods. The results are shown in Tables 8 to 9 below.

[Recycled pulp yield] It was calculated from the pulp discharged during flotation treatment by the following equation.

[0054]

(Equation 1)

[Degree of dullness] The obtained pulp sheet was evaluated on a five-point scale by visual judgment. The larger the number, the less dullness and good.

[0056]

[Table 8]

[0057]

[Table 9]

From the results shown in Tables 8 and 9, all Examples had high whiteness, no problem of dullness, and had high yield. In particular, the three-component type deinking agent of the example product shows much better whiteness than the two-component type deinking agent, has no problem with the degree of dullness, and has a much higher yield of recycled pulp. Met.

On the other hand, the whiteness, the dullness, and the yield of the recycled pulp were all lower in the comparative example than in all the examples, and it is clear that these characteristics are inferior in these characteristics. is there. Above all, in Comparative Examples 19 and 20, the addition amount was 0.35% by weight, which was 3 times more than other deinking agents.
Despite the setting of twice or more, the whiteness was low, the evaluation of the degree of dullness was inferior, and the yield of recycled pulp was also low.

[0060]

As described above, the deinking agent of the present invention contains the aforementioned component A and component B in a specific combination ratio. Excellent removability. Therefore, when this deinking agent is used for recycling used paper, high-quality recycled paper having high whiteness can be obtained. Then, high-quality recycled pulp can be obtained at a high yield even if waste paper that is difficult to recycle is mixed in or regardless of a change in printing technology, type of waste paper, and the like. In addition, with the deinking agent of the present invention, these excellent characteristics can be obtained with a small amount of use, and the cost in the recycling of used paper can be reduced.

When the above two compounds are used in a specific combination ratio and a higher fatty acid (component (C)) having a specific carbon number is used in combination, the ink is agglomerated to form large ink particles. The effect that the coagulated ink can be efficiently removed by the rotator is obtained.

Further, the weight ratio of the total amount (α) of the components (A) and (B) to the component (C) [(α) /
When (C)] is set to a specific ratio, the ink cohesive force is appropriately adjusted, and a large number of ink aggregates having a particle size that can be easily removed by the flotator are formed. By this effect, an effect is obtained that the amount of ink remaining in the post-flotation step is significantly reduced.

Claims (3)

[Claims] 1. The following component (A) and component (B):
In the weight ratio [(A) / (B)], (A) / (B) = 91 /
A deinking agent for recycling used paper, which is contained at a ratio of 9 to 99/1. (A) A compound represented by the following general formula (1). Embedded image (B) a compound represented by the following general formula (2). Embedded image 2. The deinking agent for recycling used paper according to claim 1, further comprising the following component (C) in addition to the components (A) and (B). (C) A higher fatty acid having 14 to 22 carbon atoms. 3. The weight ratio of the total amount (α) of the components (A) and (B) to the component (C) [(α) /
(C)] is set in the ratio of (α) / (C) = 70/30 to 93/7.