JP2922076B2 - 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 newspapers, magazines,
The present invention relates to a deinking agent for recycling used paper used in obtaining recycled pulp from used printed paper such as used paper, and more particularly to a deinking agent for recycling used paper suitable for use in a flotation method.

[0002]

2. Description of the Related Art It has long been practiced to recycle used printed paper to make it into papermaking raw material again. However, in recent years, from the standpoint of effective use of resources and environmental protection, the recycling of printed waste paper has become increasingly important, and the use of recycled pulp has been expanding. When reusing printed waste paper, an alkali agent such as caustic soda, sodium carbonate and sodium silicate, a bleaching agent such as hydrogen peroxide and sodium hypochlorite, EDTA, D
Along with chelating agents such as TPA, as deinking agents, fatty acid, anionic activators such as alkyl benzene sulfonate, α-olefin sulfonate, higher alcohol sulfate, dialkyl sulfosuccinate, higher alcohol, alkyl phenol, fatty acid, etc. Nonionic surfactants such as alkylene oxide adducts of alkanolamides have been used alone or in combination of two or more. On the other hand, from the point of view of the deinking device, in the defibration process, in order to efficiently remove the ink from the pulp, the processing devices such as kneaders, refiners, dispersers, etc. were improved. High floatator, multi-injector, PD
There are improved devices such as M cells. However, the above-mentioned deinking agent has insufficient ability to collect the peeled ink, and it has not been possible to obtain high-quality recycled pulp with high whiteness and little residual ink. Also, the foaming properties of the deinking agent are too strong,
There are problems such as the inability to perform stable operation, such as the inability to remove bubbles by the flotation process and the decrease in yield resulting in a decrease in production capacity.

[0003] In recent years, many patents have been filed with respect to deinking agents for higher alcohol nonionic surfactants and methods of using the same. For example, a method for deinking waste paper using a mixture of alcohol and alkylphenol to which a mixture of ethylene oxide and propylene oxide is added in a content of ethylene oxide in the range of 50 to 95% (Japanese Unexamined Patent Publication No.
JP-A-5-51891), a method for deinking waste paper using a mixture obtained by adding 1 to 50 mol of propylene oxide to an alcohol and an alkylphenol and adding a mixture of ethylene oxide and propylene oxide
No. 1892), a deinking agent for recycling used paper using a mixture obtained by adding 3 to 20 mol of ethylene oxide to an alcohol and an alkylphenol and adding a mixture of ethylene oxide and propylene oxide (Japanese Patent Laid-Open No. 62-250291).
However, the product obtained by the addition method of mixing these alkylene oxides contains a large amount of ethylene oxide at the terminal, so that it has a strong effect as a hydrophilic property, and has a strong ink peeling power and ink trapping ability. It has a weak collective power, cannot efficiently remove ink from pulp, and cannot provide high-quality recycled pulp with high whiteness and low residual ink.
Further, the recent deinking apparatus has a problem that the foaming property is so strong that the foam during the flotation process overflows, the pulp yield decreases, and a stable operation cannot be performed.

Further, a deinking agent obtained by adding propylene oxide or a mixture of propylene oxide and ethylene oxide (containing 80% or more of propylene oxide) to an alcohol having 2 to 12 carbon atoms and sequentially adding ethylene oxide (Japanese Patent Laid-Open No. 51-84905). Publication), but a large amount of propylene oxide is added to the short-chain alcohol, so that the action as hydrophobicity becomes too strong, so that the peeling force and the collecting force of the ink are reduced, and a high whiteness reproduction is performed. I cannot get pulp. Further, a higher alcohol obtained by sulfated an adduct of propylene oxide and a higher alcohol having 5 to 25 mol of ethylene oxide and 1 to 10 moles of propylene oxide
A deinking agent for recycling used paper (Japanese Patent Application Laid-Open No. 56-79795) containing a molar sequential adduct in a ratio of 100/0 to 20/80 has also been proposed. Recovered pulp with high whiteness cannot be obtained because of low collecting power. However, by using a higher alcohol-based sulfate together, the foam amount during the flotation treatment can be adjusted appropriately.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to efficiently release ink from used printing paper in a defibration process, and is excellent in the ability of collecting release ink and appropriate foaming in flotation treatment, and has high whiteness and residual ink. It is an object of the present invention to provide a deinking agent for recycling used paper, which can obtain recycled pulp having a small amount of pulp.

[0006]

The present invention has been made based on the finding that the above problems can be efficiently solved by using a non-ionic deinking agent of a propylene-ethylene block addition type having a specific structure in combination with a fatty acid or a salt thereof. It was based on that. That is, the present invention provides a deinking agent for recycling waste paper, comprising (a) a compound represented by the following general formula I and (b) a higher fatty acid having 12 to 24 carbon atoms or a salt thereof.

Embedded image R ¹ O— (PO) m— (EO) n— (XO) k—R ² (I) (wherein, R ¹ is an alkyl or alkenyl group having 12 to 22 carbon atoms, and R ² is Hydrogen or an acyl group having 2 to 24 carbon atoms,
PO, EO and XO are a propylene oxide unit, an ethylene oxide unit and an alkylene oxide unit having 3 or more carbon atoms, respectively, m = 1-8, n = 10-4
0 and k are numbers such that the total number of carbon atoms of the polymerized XO is 3 to 120. In the formula, the additional form of PO and EO is a block. )

Further, there is provided a deinking agent for recycling used paper, wherein (c) a compound represented by the general formula II is used in combination with the above deinking agent. According to this, it is possible to adjust to appropriate foaming during operation.

## STR4 ## ^{R 3 O (AO) p SO} 3 M (II) ( wherein, R ³ is an alkyl or alkenyl group having 12 to 24 carbon atoms, AO represents ethylene oxide and / or propylene oxide, p is 1 And M is hydrogen, an alkali metal, ammonium or an alkanolamine.) The ether compound represented by the general formula I, which is the component (a) of the present invention, is a compound having a higher carbon number of 12 to 22. It can be produced by first adding propylene oxide to an alcohol, adding ethylene oxide to the terminal hydroxyl group, and further adding XO which is an alkylene oxide having 3 or more carbon atoms. Next, if desired, the terminal hydroxyl group may be reacted with a carboxylic acid having 2 to 24 carbon atoms to effect esterification. Here, XO alone or a polyoxyalkylene group formed by polymerization is hydrophobic and has a total carbon number of 3 to 120. Here, two or more kinds of alkylene oxides may be blocked or randomly added as XO. XO which is an alkylene oxide having 3 or more carbon atoms
Examples thereof include propylene oxide, butylene oxide, butadiene oxide, hexylene oxide, styrene oxide, α-olefin oxide and the like. Of these, alkylene oxides having 3 to 30 carbon atoms are preferred, and propylene oxide is particularly preferred.

In the ether compound represented by the general formula (I), the molecular weight of the (EO) n moiety and the (XO) k-R
The ratio of the molecular weights of the ^two parts is preferably 0.2 to 2.0, and more preferably 0.3 to 1.8. The ether compound represented by the general formula I having the above structure has a high affinity for ink as compared with a known higher alcohol-based deinking agent. On the other hand, the ink peeling effect is high. Further, since the mixing in a specific range (EO) n moiety and (XO) k-R ² moiety at a specific ratio, it has high affinity at the time of hydrophobic strong flotation and peeled ink Therefore, it is excellent in collecting power of fine ink of 4 μm or less, which has been difficult in the past. Therefore, the ink peeled off in the flotation treatment can be efficiently separated and removed from the pulp by the foam, and as a result, a regenerated pulp having a high whiteness and a low b value and a high b value can be obtained. If this molecular weight ratio exceeds 2.0, hydrophilicity increases, and the ink affinity and ink-collecting power during flotation treatment are reduced. On the other hand, when the molecular weight ratio is less than 0.2, foaming is low in the flotation treatment, bubbles are not sufficiently removed, and the ink collecting power in the flotation treatment is reduced. When the molecular weight ratio is from 0.3 to 1.8, the ink-collecting power is further improved. In Formula II,
m = 1 to 8, n = 10 to 40, k is a number such that the total number of carbon atoms of the polymerized XO becomes 3 to 120,
12-35 and 15-120 are preferred. When XO is propylene oxide and R ² is hydrogen, the sum of m and k is preferably from 8 to 35, and particularly preferably from 11 to 35.

The higher alcohol which forms the alcohol residue of R ¹ has 12 to 22 carbon atoms, preferably 16 to 22 carbon atoms.
22, more preferably 18 to 22 linear higher alcohols. Such higher alcohols include, for example, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, nonadeca alcohol, elaidyl alcohol, behenyl alcohol, oleyl alcohol and alcohols derived from animal and vegetable oils and fatty acids, such as beef tallow alcohol, fish oil alcohol, pig Fatty alcohols and their cured products are exemplified. R ² is hydrogen or an acyl group having 2 to 24, preferably 2 to 12 carbon atoms, particularly preferably hydrogen.

When the carbon number of the higher alcohol in the deinking agent is shorter than the above range, the hydrophobicity is insufficient due to the short chain length of the alkyl group, and the molecular weight ratio of ethylene oxide to alkylene oxide or its acyl compound falls within the above range. However, the ability to collect the ink peeled off during the flotation treatment is insufficient, and a high-quality recycled pulp having high whiteness cannot be obtained. On the other hand, when the alkyl group is longer than the above range, the deinking agent does not dissolve or disperse at the time of disaggregation, so that high-quality pulp having high whiteness and low residual ink cannot be obtained. In the present invention, when the above ether compound is produced, the water content in the reaction system is set to 0.3% or less, and a basic catalyst such as sodium hydroxide or potassium hydroxide or a magnesium oxide-aluminum solid catalyst is added. The amount can be constantly added to the intermediate product in each alkylene oxide addition step, 0.35% or less based on the final product, and the reaction can be carried out under the conditions of a generally performed alkylene oxide addition reaction. Incidentally, the alkylene oxide can be added to the higher alcohol by reacting the alkylene oxide for several hours at about 100 to 200 ° C. and 1 to 3 kg / cm ² in the presence of a catalytic amount of potassium hydroxide.

The polyalkylene oxide such as polyethylene glycol, polypropylene glycol and ethylene oxide-propylene oxide copolymer contained in the product thus obtained is contained in an amount of about 0.1 to about 5%.
% By weight, preferably 0.3 to 3% by weight. However, after producing the above ether compound, a polyalkylene glycol can be added so as to be in the above range. And, at least 99.9 to 95% by weight of at least one of the above ether compounds and about 0.1 to 5
It is preferred to use a weight percent mixture as component (a).

The component (b) of the present invention has 12 to 24 carbon atoms.
Saturated, unsaturated, linear or branched fatty acids or salts thereof, for example, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, margaric acid, palmitic acid, stearic acid, elaidic acid, behenic acid, oleic acid, Examples thereof include linoleic acid, linoleic acid, tallow fatty acid, tallow hardened fatty acid, palm oil fatty acid, and coconut oil fatty acid, and these can be used alone or in combination. Examples of the salts include alkyl metal salts such as sodium and potassium, alkaline earth metal salts, ammonium salts, and amine salts such as alkanolamine salts.

The compound represented by the general formula II, which is the component (c) of the present invention, can be produced by adding an alkylene oxide to a higher alcohol having 12 to 24 carbon atoms and further sulfating a terminal hydroxyl group. . R ³ has 1 carbon atom
2-24, preferably 12-16 alkyl or alkenyl groups. AO is ethylene oxide or propylene oxide alone or as a mixture, and the number of added moles p is 1 to 8 mol. When a mixture of ethylene oxide or propylene oxide is used, block or random addition may be used. The compound represented by the general formula II having such a structure is excellent in foaming property during flotation treatment. This sulfated product can be produced by sulfating an alkylene oxide adduct of a higher alcohol with chlorosulfonic acid or sulfuric anhydride under generally used conditions. In the present invention, an unneutralized product can be used,
An alkali metal such as sodium or potassium if desired;
It may be neutralized with ammonium or alkanolamine.

In the deinking agent of the present invention, the components (a) and (b)
May be arbitrarily selected, but it is preferable that the weight ratio of the components (a) and (b) is 90/10 to 60/40, and it is particularly preferable that the ratio is 90/10 to 70/30. When component (c) is used, component (a) +
It is preferred that the total amount of (b) and (c) be in a weight ratio of 95/5 to 55/45. That is, when the content is within these ranges, the amount of foaming can be easily adjusted, and the quality of the recycled pulp does not decrease due to a decrease in ink collecting power during flotation treatment, and the operation stability can be ensured. The deinking agent of the present invention is an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, a polymer surfactant, and a polymer dispersing agent within a range that achieves the object of the present invention. Alternatively, an enzyme may be used in combination.

The components (a) and (b) of the present invention or a mixture thereof with the component (c) may be added in portions to the waste paper disintegration step, the ripening step or both steps, or the component (a)
Even if the component (b) or (c) is dividedly added in the flotation step and the mixing ratio during the flotation treatment is the above-mentioned mixing ratio, a favorable effect is exhibited. The addition amount is preferably 0.1 to 2% by weight (hereinafter abbreviated as%) based on the raw waste paper. Within this range, a high-quality recycled pulp with high whiteness and low residual ink can be obtained, and stable operation can be obtained. When deinking treatment is carried out using the product of the present invention, a bleaching agent such as sodium hydroxide, sodium silicate, sodium carbonate or hydrogen peroxide as the case may be used in the disaggregation step in addition to the product of the present invention. Pulp concentration 4-25%, temperature 20-70
° C, pH = 7.5-11.5, preferably 8.0-1
It is preferred to use 1.5. When the pulp concentration is 3% or less or 20 ° C. or less, the unpulled pulp increases due to a small frictional force between the pulp fibers at the time of defibration, so that the pulp cannot be used as a papermaking raw material or the residual ink increases. On the other hand, if the pulp concentration is 25% or more and the temperature is 70 ° C. or more, the frictional force between the pulp fibers is too strong, or the paper strength of the regenerated pulp formed by heat becomes weak, and high-quality regenerated pulp cannot be obtained. . If the pH at the time of defibration is 7.5 or less, the degree of swelling of the pulp fibers at the time of defibration is low, so that the amount of unfiberized fibers is increased and the pulp fibers cannot be used as a raw material for papermaking, or the amount of residual ink is increased, resulting in a high ink. Quality recycled pulp cannot be obtained. When the pH is 11.5 or more, the pulp turns yellow due to alkali baking, causing a decrease in whiteness and a decrease in paper strength.

The ripening step can be performed under the same chemical conditions as in the defibration step. At this time, the pulp concentration is 10 to 30%,
The aging is preferably performed at a temperature of 30 to 80 ° C. for 1 hour or more. If the pulp concentration is 10% or less and the temperature is 30 ° C. or less, a sufficient aging effect cannot be obtained, and high-quality recycled pulp cannot be obtained. On the other hand, if the temperature is 80 ° C. or higher, there is a disadvantage that the paper strength is reduced by heat. On the other hand, when the pulp concentration is 30% or more, a sufficient wet oil state cannot be obtained, and the aging effect cannot be obtained. The peeled ink has a pulp concentration of 0.5 to 1.5%,
By performing flotation at a temperature of 20 to 45 ° C., it can be efficiently removed from the pulp slurry. Furthermore, even if the product of the present invention has a process usually used in a deinking process such as a dilution dehydration, a screen, a disperser, and a kneader process during the process, the quality and operability of the recycled pulp are not affected. Does not affect, apart from the above-described defibration and aging processes, a process for removing ink, for example, a kneader,
The present deinking agent may be added to a refiner, a disperser or the like.

[0017]

According to the known deinking agent, alcohol obtained by successively polymerizing ethylene oxide and propylene oxide has a moderately strong ink peeling power and ink collecting power, but has a low foaming property during flotation treatment. In addition, the foam cannot be sufficiently removed, and a recycled pulp having high whiteness cannot be obtained. On the other hand, a mixture obtained by adding a mixture of ethylene oxide and propylene oxide to an alcohol cannot obtain a high whiteness recycled pulp because the ink peeling power and the ink collecting power are weak. Further, since the foaming property during the flotation treatment is strong, the amount of foam becomes too large, so that a stable operation cannot be obtained. However, when the compound of the component (a) of the present invention is used, the ink peeling power and the ink collecting power can be increased, and when the fatty acid or salt of the component (b) is used in combination, fine ink is also collected due to a synergistic effect. It is possible to obtain high-quality recycled pulp without dullness. Further, component (c)
By mixing the compounds shown in the above, it is possible to moderately adjust the foaming property at the time of flotation treatment due to fluctuations in the printing waste paper such as newspaper waste paper, flyers, copy OA waste paper and the like, which have deteriorated in the summer, and the blending ratio. Good operability without overflow or pulp yield loss can be maintained. Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0018]

【Example】

Production Example Stearyl alcohol (1 mol) and a catalytic amount of KOH were charged into an autoclave, replaced with nitrogen, and then dehydrated under reduced pressure to reduce the water content in the system to 0.07%.
Mol) at 125 ° C. and 3.0 kg / cm ² or less, aged and
An O adduct was obtained. Subsequently, ethylene oxide (30
Mol) at 160 ° C. and 3.0 kg / cm ² or less.
An O-EO adduct was obtained. In addition, propylene oxide (14
Mol) at 125 ° C. and 3.0 kg / cm ² or less, aged and
An O-EO-PO adduct was obtained (deinking agent a-1). In addition, deinking agents a-2 to a-4 were produced in the same manner.

Example Printed waste paper as raw material (offset printed waste paper / letter printing waste paper /
After cutting the leaflet (4/3/3 weight ratio) into 3 × 3 cm, it was put into a pulp disintegrator, and 1.0% caustic soda, 3.5% sodium silicate No. 3, 3.5% hydrogen peroxide (based on the weight of the raw waste paper). (Active ingredient) 1.0%, and the deinking agents shown in Tables 1 and 2
After adding 0.35% at an addition ratio shown in 3, hot water was added so that the pulp concentration became 15%, and defibration treatment was performed at 55 ° C. for 15 minutes. The obtained pulp slurry was heated at 65 ° C and 60 ° C.
Soak for 5 minutes, add water to this and add pulp
% For 1 minute. Thereafter, warm water was added to dilute the pulp to a concentration of 1%, and a flotation treatment was performed at 30 ° C. for 7 minutes. Next, the pulp slurry after the flotation treatment was concentrated to 10%, and then diluted to 1% with water to prepare a pulp sheet using a tappy sheet machine. In addition, at the time of disaggregation
The pH was 10.4 and the pH during soaking was 10.3.
Was. The whiteness of the obtained pulp sheet was measured with a colorimetric colorimeter, and the residual ink area ratio was measured with an image analyzer. The results are shown in Table-3. In the table, "dullness" is not always proportional to the apparent color tone even if the whiteness of the recycled paper is high. Therefore, the pulp sheet was visually evaluated and evaluated in three steps. 1: noticeable dullness; 2: slight dullness; 3: dullness. The operability (foam) during flotation treatment was evaluated according to the following criteria. A: Good operability B: Slightly large foam but no operability problem D: Too much foam to disable operation C: Slightly small foam but no operability problem E: Too little foam to disable operation

[0020]

Table 1 Deinking agent a component R ¹ O- (PO) m- (EO) n- (XO) k-R ² Deinking No. alkyl group m / n (XO) k- R 2 M 1 / M 2 The total number of carbon atoms of the by-product _{(wt%) a-1 C 18 3,30} 42 1.62 0.56 a- _{2 C 20 1,35 60 1.32 1.98 a} -3 C 16 4,25 60 1.02 1.37 a-4 C 22 6,12 92 0.36 2.81 * M 1 is, (EO ) molecular weight M ₂ of n is (XO) k-R ² having a molecular weight of XO is propylene oxide (No1,2,4) or butylene oxide (No3), R ² is hydrogen (No1～
3) or a methyl ester group (No. 4).

[0021]

Table 2 Table 2 Deinking agent c component [R ³ O (A
O) p SO ₃ M] No. R ³ AO *) type alkyl group types and addition molar number of _{M p c-1 C 14 EO} 3 potassium _{c-2 C 12 PO 5 EO} 3 ( block) sodium _{c-3 C 12-15 EO 2 PO} 2 ( Random ) Triethanolamine ─────────────────────────────────── *) EO is ethylene oxide, PO is propylene oxide Show.

[0022]

[Table 3] Table-3 Evaluation results No. a component / fatty acid / c component weight ratio Whiteness Number of remaining ink *) Dullness Operability 1 a-1 / stearic acid (90/10) 56.2 0.241 3 C2a-3 / sodium tallow fatty acid 56 0.70.23C (60/40) 3a-2 / tallow hardened fatty acid / C-1 57.0 0.2083A (81/9/10) 4a-1 / palm oil fatty acid potassium 57. 5 0.165 3 A / C-2 (60/15/25) 5 a-4 / coconut oil fatty acid / C-3 57.3 0.182 3B (36/24/40) 6 a-4 55. 80.274 2 C 7 C-1 51.9 1.158 1 D 8 Tallow alcohol PO ₅ EO ₁₀ H 52.2 1.0942 A / tallow fatty acid potassium (80/20) 9 C ₁₈ H ₃₇ O ( EO ₄₀ / PO ₁₀ ) H 52.5 1.047 2 E (R form) / stearic acid (50/50) 10 C ₁₈ H ₃₇ OEO ₁₅ PO ₅ H / linoleic acid / C ₁₂ H ₂₅ OPO ₂ SO ₃ NH ₄ (65/10/25) 53.1 0.973 2 A Nos. 6 to 10 are comparative examples. In the table, *) Unit (pieces / field) R body indicates random body.

Claims (4)

(57) [Claims] 1. A deinking agent for recycling waste paper, comprising (a) a compound represented by the following general formula I and (b) a higher fatty acid having 12 to 24 carbon atoms or a salt thereof. R ¹ O- (PO) m- (EO) n- ( PO ) k-R ² (I) (wherein, R ¹ is an alkyl group or alkenyl group having 12 to 22 carbon atoms, and R ² is Hydrogen or an acyl group having 2 to 24 carbon atoms,
PO and EO are propylene oxide and ethylene oxide units, m = 1 to 8, n = 10 to 40, and k is (P
O) a number in which the total number of carbon atoms of k is 3 to 120, (EO)
Ratio between the molecular weight of the n part and the molecular weight of the (PO) k-R ² part
Is 0.2 to 2.0 . ) 2. The deinking agent for recycling waste paper according to claim 1, further comprising (c) a compound represented by the general formula II. Embedded image R ³ O (AO) pSO ₃ M (II) (wherein, R ³ represents an alkyl group or an alkenyl group having 12 to 24 carbon atoms, AO represents ethylene oxide and / or propylene oxide, and p represents 1 to Represents the number 8 and M is hydrogen, alkali metal, ammonium or alkanolamine.) 3. Component (a) / (b) is 90 / 10-60
The deinking agent for recycling waste paper according to claim 1 or 2, which has a weight ratio of / 40. 4. The sum of components (a) + (b) / (c) is 9
The deinking agent for recycling waste paper according to claim 2, wherein the deinking agent is in a weight ratio of 5/5 to 55/45.