JP2999363B2 - Deinking agent for recycled paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking agent for recycling used paper, and more particularly, to a deinking agent for recycling used paper having excellent deinking performance and having the deinking performance required in each deinking process. .

[0002]

2. Description of the Related Art Recycling of used paper is carried out by removing ink from used raw paper by deinking, obtaining recycled pulp, and manufacturing recycled paper. Due to an increase in demand for printing and the development of printing technology, the properties of paper used as raw material waste have diversified, and inks from paper to paper have been loosely coupled to those that are strong. In addition, deinking water has been circulated for environmental protection and cost reduction, and water of various qualities has been used in the deinking process.

As described above, in today's deinking process, the properties and operating environment of the raw material waste paper have become extremely diversified, and the machinery used for the deinking process finely adjusts the deinking conditions in accordance with these. It is difficult. Accordingly, it has been practiced to diversify the performance of the deinking agent to cope with changes in deinking conditions.

The basic functions required of a deinking agent include, for example, the flotation method, (1) peeling force of ink from waste paper (2) moderate cohesive force of ink (3) collection of coagulated ink (4) There are four types of defoaming or defoaming power for efficient operation, but with the recent diversification of deinking environment as mentioned above, deinking These functions must be finely controlled according to the characteristics of each deinking process that constitutes the processing.

[0005] In addition, while the floatator at the time of the introduction of the floatation method has a low foaming power, a deinking agent having a strong foaming power has been required. There is a demand for a deinking agent that is suppressed. However, many of the flotators currently in use at the time of the introduction of the flotation system are in operation, and accordingly, it is necessary to use a deinking agent having a different foaming property.

Hitherto, polyoxyethylene alkyl ethers have been widely used as deinking agents because of their good ink releasability from waste paper. However, polyoxyethylene alkyl ethers have a low foaming power. In many cases, an anionic surfactant having a high foaming power is used in combination to make up for this. In addition, if the deinking conditions are diversified as described above by using a deinking agent in combination, the types of deinking agents used are increased, and there are many operational problems.

[0007] Therefore, attempts have been made to improve the deinking performance of polyoxyethylene alkyl ethers, or to add several types of functions required for each deinking step to cope with the deinking agent. For example, JP-A-50-142804, JP-A-55-51891, JP-A-56-79795, JP-A-59-137588, JP-A-61-41386, and JP-A-61-41386 JP-A-62-250291 and JP-A-3-35067 describe that a nonionic surfactant obtained by adding ethylene oxide, propylene oxide and butylene oxide to a higher alcohol or a phenolic compound is used as a deinking agent. Have been. The basic idea common to these prior arts is that as a deinking agent, a hydrophilic group, an ethylene oxide group and a propylene oxide group with a low hydrophilicity, are added to the hydroxyl group of a higher alcohol in a different arrangement to change the arrangement. Is to diversify its functions.

However, Japanese Patent Application Laid-Open No. 55-51891 discloses
When the deinking agents described in JP-A-56-79795, JP-A-61-41386, JP-A-62-250291 and JP-A-3-35067 are used, bubbles generated are It becomes too stable, and it becomes difficult to control the defoaming property in the system, and there is a problem that bubbles often overflow in the foam discharging step of the floatation. Also, Japanese Patent Application Laid-Open No. 50-142804 and
The deinking agent described in JP-A-59-137588 could not obtain high-quality deinked pulp due to insufficient ink removal and discharge from the deinking system.

In addition, these conventional techniques cannot easily control important functions (such as releasability, cohesion, foaming properties, collecting properties, defoaming properties, etc.) as deinking agents. It is considered that it is difficult to sufficiently cope with a deinking environment in which diversification is expected.

In addition, when deinking is performed using waste paper that has been thermally degraded as a raw material, it is very difficult to remove the ink because the ink and the paper are firmly bound together. Therefore, the optimization of the deinking conditions is very troublesome. A good deinking effect cannot be obtained even if the deinking agent disclosed in each of the above-mentioned prior arts is used in the deinking treatment using such thermally degraded waste paper.

[0011]

The present inventors have found that the performance as a deinking agent is closely related to the arrangement of alkylene oxides to be added to a compound containing a hydroxyl group such as a higher alcohol. As a result of further study of the relationship between the arrangement of the alkylene oxide groups to be added to the hydroxyl group-containing compound and the deinking performance, the hydroxyl groups of the hydroxyl group-containing compounds have a low hydrophilicity such as a propylene oxide group and a butylene oxide group with a branched chain. By arranging an alkylene oxide group having, then by placing a highly hydrophilic, hydrocarbon chain linear ethylene oxide group, and further arranging propylene oxide, butylene oxide, such as ink peeling, ink aggregation or ink collection Functions related to the affinity between ink and deinking agent, and deinking agents such as foaming and defoaming properties It found that affinity can be easily controlled both important functions, and have completed the present invention.

That is, the present invention provides a deinking agent for recycling used paper, which comprises a compound represented by the following general formula (I). During _{R 1 -O- (C x H 2x} O) l (AO) m (C y H 2y O) n -H (I) [wherein, R _1: 1 monohydric higher alcohol or the number of carbon atoms of 8 to 24 carbon atoms 6 ~
A residue obtained by removing a hydroxyl group from an alkylphenol having 16 linear or branched alkyl or alkenyl groups. AO: 2 to 2 carbon atoms including an ethylene oxide group as essential.
A group in which one or more alkylene oxide groups of 4 are arranged in blocks or randomly x, y: 3 or 4, respectively, which may be the same or different l: 1 ≦ l ≦ 300 m: 50 <m ≦ 300 n: It means that 1 ≦ n ≦ 300. Further, the present invention provides a deinking agent for recycling used paper, comprising a compound represented by the following general formula (II). R _1- [O- (C _x H _2x O) _l (AO) _m (C _y H _2y O) _n -H] _p (II) [wherein R ₁ represents a hydroxyl group from a compound having p hydroxyl groups. Excluded residue AO: 2 to 2 carbon atoms containing ethylene oxide group as essential
A group in which one or more alkylene oxide groups of 4 are arranged blockwise or randomly p: 2 to 16 x, y: 3 or 4, respectively, which may be the same or different l: 1 ≦ l ≦ 300 m: 1 ≦ m ≦ 300 n means 1 ≦ n ≦ 300. ].

The present invention also relates to the compound represented by the above general formula (I) or (I)
An object of the present invention is to provide a deinking agent comprising a compound having the skeleton of I) and obtained by variously changing the number of moles of alkylene oxide added. Hereinafter, a specific description will be given.

(A) Compound Represented by General Formula (I) The compound represented by the general formula (I) according to the present invention is a monohydric higher alcohol having 8 to 24 carbon atoms or a C 6 to C 16 monohydric alcohol. Propylene oxide (x = 3, hereinafter abbreviated as PO) or butylene oxide (x = 4, hereinafter abbreviated as BO) is added to an alkylphenol having a linear or branched alkyl group or alkenyl group, and then ethylene oxide ( Hereinafter, an alkylene oxide having 2 to 4 carbon atoms, which is abbreviated as EO), is added (A in the general formula (I)).
O) and further by adding PO (y = 3) or BO (y = 4). The addition reaction of the alkylene oxide may be performed according to a conventionally known method, and is not particularly limited. For example, after adding a catalytic amount of an alkaline substance to an alcohol, firstly PO and / or BO are subjected to a predetermined amount of addition reaction, and then EO and PO and / or BO are subjected to random or block addition polymerization reaction, It can be obtained by adding PO and / or BO again.
Of course, this is only an example, and it is also possible to manufacture by another method.

In the general formula (I), the AO moiety is
It is essential to use EO alone or a mixture of EO and PO in order to improve foaming properties. In particular, EO alone is preferred from the viewpoint of bubble elimination. EO in all alkylene oxides is 30-80 mol%
Is preferred. When the ratio of EO is out of this range, the foaming property is reduced, or the foam removing property is reduced. Also, AO
(C _x H _2x O) _l and (C _y H _2y O) _n sandwiching the part, it is preferable to add PO to one of them in consideration of economical efficiency, and in particular, both are PO block additions. Is preferred.

In the general formula (I), l, m and n are the number of moles of alkylene oxide added to 1 mole of alcohol or alkylphenol, and 1 ≦ l ≦ 300, 50
<M ≦ 300, 1 ≦ n ≦ 300. If l, m and n are out of this range, the deinking function, that is, any of the ink peeling performance, agglomeration performance, foaming performance, collection performance and defoaming performance does not reach the required level and is inappropriate. . In particular, the number of moles of EO added is 50
If the amount is less than mol, a deinking agent that generates a sufficient amount of foam cannot be obtained even with a flotator having a weak foaming power. However, if the number of added moles is too large, not only foaming than necessary, but also foaming becomes difficult and the cost becomes unnecessarily high. Therefore, the upper limit of the number of added moles is 300 moles. In particular, from the viewpoint of both deinking performance and cost, 1 ≦ l
≦ 50, 50 <m ≦ 100, 1 ≦ n ≦ 50 are preferred.

Further, x and y in the general formula (I) are 3 or 4, respectively, and x and y may be the same or different.

The compound (A) can be obtained by adding an alkylene oxide to a higher alcohol or an alkylphenol. However, the added mole number of each alkylene oxide needs to be within the range specified by each.

Such higher alcohols include those having 8 carbon atoms.
Those having from 24 to 24 linear or branched alkyl or alkenyl groups are used, and primary or secondary alcohols are preferred. When the carbon number of the higher alcohol is less than 8, the ink collecting power decreases, and when the carbon number exceeds 24, the ink peeling power decreases. Such higher alcohols include octanol, nonanol, decanol, undecanol,
Dodecanol, tetradecanol, hexadecanol,
Octadecanol, eicosyl alcohol, docosyl alcohol, 2-ethylhexanol, 2-ethylundecanol and the like can be mentioned.

As the phenolic compound, an alkylphenol having a linear or branched alkyl group or alkenyl group having 6 to 16 carbon atoms is used. Specifically, phenol, cresol, xylenol, butylphenol, nonylphenol, Dodecylphenol,
Substituted phenols such as aminophenol and hydroxybenzoic acid, and substituted naphthols such as naphthol, methylnaphthol, butylnaphthol and octylnaphthol are exemplified. These alkyl phenols are preferable because of their good ink collecting power and ink peeling power.

(B) Compound Represented by General Formula (II) The number of compounds represented by general formula (II) is p (p = 2 to 16)
Can be obtained by adding an alkylene oxide to a compound having a hydroxyl group of the formula (1), but the compound represented by the general formula (II) is particularly excellent in bubble elimination property.

Examples of the compound having p hydroxyl groups include polyhydric alcohols, polyhydric phenol compounds, and bisphenol compounds.

Examples of polyhydric alcohols include diols such as ethylene glycol, propylene glycol and butylene glycol; polyglycerins such as glycerin, diglycerin and triglycerin; trimethylolpropane, pentaerythritol, sorbitol, sucrose,
Reduced maltose and the like.

Examples of polyhydric phenol compounds include polyhydric phenols such as catechol, resorcinol and pyrogallol, and polyhydric naphthols such as naphtoresorcin and α-naphthohydroquinone.

Further, as the bisphenol compound,
Isopropylidene diphenol, ethylidene diphenol, isasubtilidene diphenol, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone and the like.

In the general formula (II), l, m and n are 1
≦ l ≦ 300, 1 ≦ m ≦ 300, 1 ≦ n ≦ 300, and particularly preferably 1 ≦ l ≦ 100, 10 ≦ m ≦ 50, and 1 ≦ n ≦ 100.

In the general formula (II), the AO moiety is
Either EO alone or a mixture of EO and PO and / or BO is preferable from the viewpoint of foaming properties. In addition, EO alone is particularly preferable from the viewpoint of bubble elimination. The EO in the total alkylene oxide is preferably 30 to 80 mol%. When the ratio of EO is out of this range, the foaming property is reduced, or the foam removing property is reduced.

Further, (C _x H _2x O) _l sandwiching the AO portion and (C _y H
_It is preferable to add PO to either one of _2yO ) _n in view of economy, and it is particularly preferable that both of them are block additions of PO (x and y are both 3). Thus x
When both and y are 3, it is particularly preferred that AO is a group in which EO and PO groups are randomly arranged, since the freezing point is lowered.

The deinking agent for recycling waste paper of the present invention described above can be obtained by appropriately changing the type, arrangement and number of moles of alkylene oxide to be added to higher alcohols, polyhydric alcohols and the like within the range specified in the present invention. The desired deinking performance required for the deinking process can be provided.
For example, it is possible to obtain a deinking agent having an optimum foaming property in accordance with the foaming power of the rotator used for the deinking process. In this case, the performance required for other steps is not impaired, so All processes can be handled with the deinking agent.

The deinking agent for recycled waste paper of the present invention is not only a deinking process using ordinary waste paper as a raw material, but also a deinking process using so-called thermally degraded waste paper that has been deteriorated by storage under sunlight or high temperature. Shows sufficient deinking effect even when used for Moreover,
Also in this case, it is easy to control the performance required for each process.

Further, the deinking agent for recycling used paper of the present invention may be added to any of the processes, either when using normal used paper or when using thermally degraded used paper. Higher quality deinked pulp can be obtained by adding to any of the steps. Generally, the deinking agent for recycling waste paper of the present invention is added to any or all of the pulping step, mixing step or flotation step. When divided addition in each step, it can be added to each step of pulping, kneading, dispersing, chemical mixing, refining,
The split ratio of the deinking agent in the pre-process and post-process is 10/90 to 90/10
(Weight ratio) is preferred, and particularly preferred is 40 / 60-60 /
40 (weight ratio). The amount of the deinking agent added is desirably in the economic range without impairing the operability, but is preferably 0.03 to 1.0% by weight based on the used raw paper.

[0032]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Examples 1 and 2 and Comparative Example 1 This example is an example in which thermally degraded waste paper is used as raw material waste paper, and a deinking agent is added to the pulp process in a lump. Heat-degraded waste paper (recovered paper obtained by blending waste paper (remaining paper of offset newsprint at 80 ° C. for one month) and flyers at a ratio of 80/20 (weight ratio)) is cut into 2 × 5 cm. A certain amount is put into a table disintegrator, and then hot water and caustic soda 0.8% (based on waste paper.
Weight basis, the same applies hereinafter. ), 2.2% sodium silicate (based on waste paper), 30%-3.5% hydrogen peroxide (based on waste paper), Table 1
Add 0.5% of deinking agent (based on waste paper) as shown in
Adjust to 15%, temperature 45 ° C. Disintegrate at a temperature of 45 ° C for 10 minutes to make waste paper into a pulp slurry. After defibration, dilute to a pulp concentration of 4%. Dehydrate with a high-speed dehydrator to reduce the pulp concentration to 25
%. Aged at a pulp concentration of 25% at a temperature of 55 ° C for 120 minutes. The kneading process is performed with a lab kneader (biaxial type, rotation speed 200 rpm). After that, add water and pulp concentration is 4%
Dilute to. Disintegrate with a desktop disintegrator for 3 minutes. Warm water is added to adjust the pulp concentration to 1% and the temperature to 30 ° C. At a temperature of 30 ° C
Apply flotation for 10 minutes. The G / L at the time of flotation (the ratio of the bubble injection amount (liter) to the pulp slurry amount (liter) at the time of floatation) was varied as shown in Table 1. At the time of flotation, the foam height of the flotator and the bubble repellency of the flotation reject were simultaneously measured. Here, the foam height of the flotator is the height (cm) of the foam from the liquid level 3 minutes after the start of the flotation, and the bubble repellency of the flotation reject refers to the foam scraped out 3 minutes after the laboratory flotation. Is taken in a 2 liter cylinder, the foam amount immediately after (H ₀ ) and one minute later (H ₁ ) is measured, and the foaming rate calculated by the following formula, where H ₀ and H ₁ are small, The higher the bubble breaking rate, the better the bubble removal.

[0034]

(Equation 1)

The pulp slurry after flotation is concentrated to a pulp concentration of 20% with a mesh wire (# 80).
Water was added to dilute the pulp concentration to 1%, and a pulp sheet was prepared using a TAPPI sheet machine. The b value of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), the number of unstripped ink was measured with an image analyzer (× 100), and the area ratio of unstripped ink (%) I asked. Also, b
The value refers to the b value in the Lab color system of the Hunter color difference formula, and the relationship with the tristimulus value XYZ is as follows.

[0036]

(Equation 2)

As can be seen from this equation, the b value is a function of Y and Z, with a positive value representing yellowish intensity and a negative value representing blueish intensity. Table 1 shows the evaluation results. The heat-degraded waste paper used in this example was obtained by mixing offset newsprint with waste paper obtained by heat-treating the remaining paper at 80 ° C for one month and a normal folding leaflet at a ratio of 80/20 (weight ratio). It is. The hardness of the water used for the deinking treatment is 5 ° dH and the hardness is C
Using aCl ₂ and MgCl ₂ , Ca / Mg = 8/2
(Molar ratio).

[0038]

[Table 1]

Examples 3 to 6 and Comparative Examples 2 to 4 This example is an example in which a thermally degraded waste paper is used as a raw material waste paper, and a deinking agent is dividedly added to a pulping step and a chemical mixing step. After the same thermally degraded waste paper as in Examples 1 and 2 and Comparative Example 1 was cut into 2 × 5 cm, a certain amount was put into a desktop disintegrator, and further heated water, caustic soda 0.2% (relative to waste paper), and
2 or 0.1% of the deinking agent shown in Table 3 (based on waste paper) is added to adjust the waste paper concentration to 5% and the temperature to 50 ° C. At a temperature of 50 ° C
Disintegrate for 15 minutes and pulverize waste paper. After disaggregation,
Dehydrate to a pulp concentration of 18%. Hot water, caustic soda 0.6
% (Based on waste paper), 2.2% sodium silicate (based on waste paper),
Add 30%-3.5% hydrogen peroxide solution (based on waste paper) and 0.2% of the deinking agent shown in Table 2 or 3 (based on waste paper), adjust the pulp concentration to 15%, and use a desktop disintegrator for 1 minute. Mix. Aging treatment was performed at a pulp concentration of 15% and a temperature of 55 ° C for 120 minutes.
Further, water is added to dilute the pulp consistency to 4%. Further, disintegrate with a desktop disintegrator for 3 minutes. Then, hot water is added to adjust the pulp concentration to 1% and the temperature to 30 ° C. A flotation treatment is performed at a temperature of 30 ° C. for 10 minutes. At this time, the foam height of the flotator and the bubble-removing property of the flotation reject were determined in Examples 1-2.
And it measured similarly to the comparative example 1 .

The pulp slurry after flotation is concentrated to a pulp concentration of 6% with a mesh wire (# 80).
Water was added to dilute the pulp concentration to 1%, and a pulp sheet was prepared using a TAPPI sheet machine. The b value of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), the number of unstripped ink was measured with an image analyzer (× 100), and the area ratio of unstripped ink (%) Was determined in the same manner as in Examples 1 and 2 and Comparative Example 1 . The hardness of the used water was 5 ° dH, and the hardness was adjusted using CaCl ₂ and MgCl _{2 so} that Ca / Mg = 8/2 (molar ratio). The above evaluation results are shown in Table 2 or Table 3 .

[0041]

[Table 2]

[0042]

[Table 3]

[Results] From the results of Tables 1 to 3 , the type and the number of moles of the alkylene oxide to be added to the compound containing a hydroxyl group are defined as in the present invention, whereby the deinking performance can be easily controlled. It can be seen that since various performances as a deinking agent can be exhibited, the performance required for each deinking process can be imparted. Moreover, excellent deinking results have been obtained despite the use of thermally degraded waste paper with severe deinking conditions as a raw material. That is, when the number of added moles of the alkylene oxide containing EO in the central portion is large, a certain amount of foaming is maintained even under the low foaming condition of floatation (G / L = 3), and the quality is hardly deteriorated. (Examples 1-1 to 1-3).

As described above, by using the deinking agent for recycling waste paper of the present invention, it is possible to sufficiently cope with the diversification of the deinking treatment, and all the deinking performances are higher than those of the conventional deinking agents. Therefore, good deinked pulp can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiromichi Takahashi 1031-10, Wakayama City Sonobe (56) References JP-A-6-257083 (JP, A) JP-A-5-263379 (JP, A) JP JP-A-5-186985 (JP, A) JP-A-6-257086 (JP, A) JP-A-4-136291 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21C 5 / 02

Claims (4)

(57) [Claims] 1. A deinking agent for recycling waste paper, comprising a compound represented by the following general formula (I). During _{R 1 -O- (C x H 2x} O) l (AO) m (C y H 2y O) n -H (I) [wherein, R _1: 1 monohydric higher alcohol or the number of carbon atoms of 8 to 24 carbon atoms 6 ~
A residue obtained by removing a hydroxyl group from an alkylphenol having 16 linear or branched alkyl or alkenyl groups. AO: 2 to 2 carbon atoms including an ethylene oxide group as essential.
A group in which one or more alkylene oxide groups of 4 are arranged in blocks or randomly x, y: 3 or 4, respectively, which may be the same or different l: 1 ≦ l ≦ 300 m: 50 <m ≦ 300 n: It means that 1 ≦ n ≦ 300. ] 2. In the general formula (I), l, m, n are 1 ≦ l ≦
The deinking agent according to claim 1, wherein 50, 50 <m ≤ 100, and 1 ≤ n ≤ 50. 3. A deinking agent for recycling waste paper, comprising a compound represented by the following general formula (II). R _1- [O- (C _x H _2x O) _l (AO) _m (C _y H _2y O) _n -H] _p (II) [wherein R ₁ represents a hydroxyl group from a compound having p hydroxyl groups. Excluded residue AO: 2 to 2 carbon atoms containing ethylene oxide group as essential
A group in which one or more alkylene oxide groups of 4 are arranged blockwise or randomly p: 2 to 16 x, y: 3 or 4, respectively, which may be the same or different l: 1 ≦ l ≦ 300 m: 1 ≦ m ≦ 300 n means 1 ≦ n ≦ 300. ] 4. In the general formula (II), l, m, n are 1 ≦ l ≦
The deinking agent according to claim 3, wherein 100, 10≤m≤50, and 1≤n≤100.