JP3279424B2 - Deinking agent - 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 used for recycling used paper such as newspapers and magazines. More specifically, when performing deinking treatment of newspapers, magazines, etc. by the flotation method and the flotation / washing combination system, a deinking agent capable of obtaining a deinked pulp having a stable operation, a high b value and a small amount of unstripped ink. About.

[0002]

BACKGROUND OF THE INVENTION Newspapers,
Recycling of magazines, etc., has been practiced for a long time, but in recent years, the effective use of pulp resources has become increasingly important from the viewpoint of shortage of pulp resources and soaring prices, furthermore, measures against garbage and protection of forest resources. It is coming. The development of advanced technology for the use of deinked pulp has been spurred to meet the growing needs. On the other hand, in recent years, waste paper is difficult to deink due to changes in printing techniques, printing methods, printing ink components, and the like, and in particular, difficult to remove ink due to thermal and oxidative deterioration of waste paper and ink in summer. Furthermore, the situation has become even more rugged in terms of deinking, such as the use of waste paper that has not been collected and used in the past.

[0003] In order to further promote deinking,
Improvements have also been made to the device. For example, a high-concentration aging treatment by installing a tower, the introduction of a disperser and a kneader for further promoting ink peeling by physical force, and the installation of a high-concentration pulverizing pulper are also included. In addition, the introduction of a high-bubble type flotator is also increasing in the flotator. However, there is a limit in improving the deinking effect by the physical method.

[0004] Chemicals that have been conventionally used to separate and remove ink and other impurities from waste paper include:
Alkaline agents such as caustic soda, sodium silicate, sodium carbonate, sodium phosphate, etc., bleaching agents such as hydrogen peroxide, hyposulfite, hypochlorite, sequestering agents such as EDTA, DTPA, etc. Anionic activators, such as alkyl benzene sulfonates, higher alcohol sulfates, α-olefin sulfonates, dialkyl sulfosuccinates, and nonionic activities such as higher alcohols, ethylene oxide adducts of alkyl phenols and fatty acids, and alkanol amides Agents have been used alone or in combination of two or more.

However, these deinking agents have a high foaming property in flotation treatment, but have a low ink collecting ability. Further, the cleaning method has a low detergency, and has a high foaming property, so that it cannot be used in a drainage process. This caused foam trouble and resulted in only low grade deinked pulp. Furthermore, since there is dullness even at high whiteness, use of deinked pulp is restricted (reduction in the amount of paperboard used below and below, blending in newsprint, etc.), and bleaching agents are used to eliminate dullness. The situation had to be increased.

In order to obtain a deinked pulp having a dull color and a bright color tone, the b value of the Hunter color difference type Lab display system may be increased. A deinked pulp having a high b value has a high removal rate of fine ink of 4 μm or less. If the b value is high, the color tone of the pulp becomes bright, so that the use of bleaching agents such as hydrogen peroxide can be reduced, the deinked pulp can be highly blended, and it can be used for one-grade applications.

There are two methods for increasing the b value, such as the method of efficiently removing the fine ink of 4 μm or less as described above or the method of using a large amount of alkalis.
However, the latter has the disadvantage that sticky (adhesive) increases, drainage load increases, and pulp becomes brittle. There are some examples of the former technique for collecting and removing fine ink of 4 μm or less, but none of them is effective.

[0008] Alkylene oxide adducts of higher fatty acids have long been known as deinking agents having high ink collecting ability. For example, Japanese Patent Nos. 1525644 and 1531613 disclose their use as deinking agents. Japanese Patent Application Laid-Open No. 64-11756 discloses a deinking agent comprising an alkylene oxide adduct of a higher fatty acid.

However, even with the use of the deinking agents disclosed in these techniques, it was not possible to obtain high-b-value deinked pulp. In addition, when a conventionally known alkylene oxide adduct of a fatty acid is used, there is a disadvantage that the amount of unreleased ink is large. Examining the behavior in the deinking process in more detail, it was found that when the above deinking agent was used, the system using a high-bubble type and high-pressure type rotator became poor in reject bubble removal, and ink was absorbed on the foam. As a result, it was found that as a result, the finished pulp had a drawback that the whiteness was reduced.

[0010]

Means for Solving the Problems The present inventors have shown excellent ink removing ability in a flotation method, a washing method and a compromise method thereof, and in particular, have a small amount of unstripped ink when a thermally deteriorated waste paper is treated. As a result of intensive research to develop a deinking pulp with high b value and a deinking agent that eliminates foam trouble and can operate stably, surprisingly, polyoxyalkylene groups containing ethylene oxide The present inventors have found that the above disadvantages can be overcome by using an alkylene oxide adduct of a higher fatty acid having a specific sequence in which propylene oxide or butylene oxide having low hydrophilicity is arranged on both sides, and have completed the present invention.

That is, the present invention provides a deinking agent containing a compound represented by the following general formula (1). R ₁ —COO— (X ₁ O) ₁₁ — (AO) _m1 — (X ₂ O) _n1 —R ₂ (1) (wherein, R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms. Or an alkenyl group, R ₂ is a linear or branched alkyl group, alkenyl group or acyl group having 1 to 22 carbon atoms, X ₁ O and X ₂ O are propylene oxide and / or
Or butylene oxide, and l ₁ and n ₁ each represent 1 to
An integer of 50, m ₁ is an integer of 10 to 100, and l ₁ , m ₁ and n
The sum of ₁ is 12-120. AO is ethylene oxide alone or ethylene oxide and propylene oxide and / or
Alternatively, it is a polyoxyalkylene group obtained by block or random polymerization of butylene oxide. Further, the present invention provides a deinking agent comprising a compound represented by the following general formula (2). R ₁ —COO— (PO) _l2 — (AO) _m2 — (PO) _n2 —H (2) (wherein, R ₁ is a linear or branched alkyl group or alkenyl group having 7 to 23 carbon atoms) PO represents propylene oxide, l ₂ is an integer of 1 to 20, m ₂ is an integer of 51 to 100, n ₂ is an integer of 1 to 50, and the sum of l ₂ , m ₂ and n ₂ is AO is an ethylene oxide alone or a polyoxyalkylene group in which ethylene oxide and propylene oxide and / or butylene oxide are block- or random-polymerized.) Also, the present invention provides a compound represented by the following general formula (3). The present invention provides a deinking agent characterized by containing a compound to be removed. R ₁ —COO— (PO) _l3 — (AO) _m3 — (PO) _n3 —H (3) (wherein, R ₁ is a linear or branched alkyl group or alkenyl group having 22 to 23 carbon atoms) PO represents propylene oxide, l ₃ is an integer of 1 to 20, m ₃ is an integer of 10 to 50,
n ₃ is an integer of 1 to 50, and the sum of l ₃ , m ₃ and n ₃ is 12
~ 120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. Further, the present invention provides a deinking agent comprising a compound represented by the following general formula (4). _{R 1 -COO- (PO) l4 -} (AO) m4 - (PO) n4 -H (4) ( In the formula, R ₁ is an alkyl or alkenyl group of 7 to 23 carbon atoms linear or branched .PO means propylene oxide, integers l ₄ is 21-50, m ₄ 10-100 integer, n ₄ is an integer of 1 to 50, the sum of l _4, m ₄ and n ₄ is AO is an ethylene oxide alone, or a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide and propylene oxide and / or butylene oxide.) Further, the present invention provides a compound represented by the following general formula (5). The present invention provides a deinking agent characterized by containing a compound to be removed. R ₁ —COO— (X ₃ O) ₁₅ — (AO) _m5 — (X ₄ O) _n5 —H (5) (wherein R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms or X ₃ O and X ₄ O are each propylene oxide and / or butylene oxide, at least one of which is butylene oxide, l ₅ and n ₅ are each an integer of 1 to 50, and m ₅ is an alkenyl group. 10-100
And the sum of l ₅ , m ₅ and n ₅ is from 12 to 120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. ).

[0012] Functions required for the deinking agent include ink releasability due to a decrease in the interfacial tension between cellulose and ink, re-adhesion prevention of ink peeled from cellulose, ink adsorbability to air bubbles, molecular orientation in a foam film. And four types of foaming property and foam breaking property depending on film thickness and viscosity.
The deinking agent must have these four functions in a well-balanced manner. The compounds of the present invention are particularly and particularly excellent.

It is extremely important that all of the compounds represented by the general formulas (1) to (5) according to the present invention satisfy the formula. Effects cannot be obtained. General formula (1)-
The compounds represented by (5) may be used alone or in combination of two or more in any of the deinking agents.

The general formulas (1), (2), (4) and (5)
When the number of carbon atoms of the R ₁ alkyl group or alkenyl group is less than 7, the ink-collecting ability is weak, high whiteness and high b value deinked pulp cannot be obtained, and the number of carbon atoms exceeds 23. And, because the releasability of the ink from cellulose becomes smaller,
A large amount of unstripped ink remains, and only deinked pulp with poor appearance can be obtained. The general formulas (1), (2), (4)
In (5) and (5), the alkyl group or alkenyl group of R ₁ in each formula may be linear or branched.

In the general formula (1), when the number of carbon atoms of R ₂ exceeds 22, the releasability of the ink from cellulose decreases, so that the remaining amount of the unremoved ink is large and the deinked pulp having poor appearance is obtained. I can only get it. An alkyl group for R ₂ ,
The alkenyl group or the acyl group may be linear or branched. When R ₂ is an acyl group, a deinking agent having the strongest cohesive force is obtained, and when an alkyl group is used, a deinking agent having an overall balance of deinking performance is obtained.

Also, in the general formula (3), when the carbon number of R ¹ exceeds 23, the ink releasability from cellulose becomes small, so that the unremoved ink remains in a large amount and the deinked pulp having poor appearance is obtained. I can only get it.

It is important that AO in each of the formulas (1) to (5) contains ethylene oxide as an essential component. When AO is propylene oxide or butylene oxide alone or in combination of two kinds of propylene and butylene oxide, it has a strong hydrophobicity, so that it acts on defoaming at the time of flotation and no foam is formed. As a result, the ink is not discharged out of the system, and the whiteness and b value of the deinked pulp decrease. Further, if the values of the added mole numbers l, m, and n of the alkylene oxide deviate from the ranges specified by the respective formulas, the necessary functions of the deinking agent will be out of balance, resulting in deterioration of deinking quality and operation trouble. . AO is preferably ethylene oxide, and the number of moles added is preferably 40 to 80 mol% based on the total number of moles of alkylene oxide added in each formula.

It is important that X ₁ O and X ₂ O in each of the general formulas (1) to (5) be propylene oxide and / or butylene oxide, respectively, which is ethylene oxide. If there is, the molecular orientation and the film thickness of the foam film change, so that the foaming property is increased, and the foam breaking property is also worse than that of propylene oxide or butylene oxide. Further, X ₁ O and X ₂ O are converted to propylene oxide and / or
Alternatively, by using butylene oxide, affinity with the ink is increased, and as a result, deinked pulp with high whiteness and high b value and good appearance can be obtained.

By using the compound represented by the general formula (1), it is possible to obtain a deinking agent having a strong cohesive force, a high ink peeling power and a high foaming power, and a good defoaming in a foam discharging process. . In addition, by using the compounds represented by the general formulas (2) to (5), a deinking agent with good foam removal can be obtained.

As described above, a deinked pulp having a stable operation, a high b value and a small amount of unstripped ink can be obtained within the range specified in the present invention.

The compounds represented by the general formulas (1) to (5) according to the present invention can be obtained by a conventionally known alkylene oxide addition reaction method, and are not particularly limited. For example, a catalytic amount of an alkaline substance is added to a fatty acid or a mixture of a fatty acid and an alcohol, and a predetermined amount of propylene oxide and / or butylene oxide is first added, followed by ethylene oxide and propylene oxide and / or butylene oxide. Is subjected to block or random addition polymerization, and then propylene oxide and / or butylene oxide are added again. Further, a fatty acid obtained by etherifying or esterifying an alkylene oxide adduct obtained in the same manner as described above can also be used. Further, a compound obtained by esterifying an alkylene oxide adduct obtained in the same manner as described above, such as alcohol, ethylene glycol and propylene glycol, can be used. Of course, these are only examples, and they can be manufactured by other methods.

The fatty acid used as a raw material of the compounds represented by the general formulas (1) to (5) according to the present invention is a fatty acid having 7 to 23 carbon atoms in the alkyl or alkenyl group corresponding to R ₁ . , Linear or branched, and specific examples thereof include caprylic acid, 2-ethylhexanoic acid, capric acid, lauric acid, palmitic acid, stearic acid, isostearic acid, hydroxystearic acid, oleic acid, and behenic acid. Palm fatty acids containing these fatty acids, such as
Fatty acids such as soybean oil fatty acids, rapeseed oil fatty acids, tall oil fatty acids, castor oil fatty acids, tallow fatty acids, palm oil fatty acids, fish oil fatty acids, etc., oils and fats obtained from other natural products, hydrogenated products of these fatty acids, synthetic fatty acids, etc. Can be.

Further, R ₂ used as a raw material of the compound represented by the general formula (1) according to the present invention has 1 to 1 carbon atoms.
Specific examples of the 22 of fatty acids, propionic acid, butyric acid, a fatty acid or the like according to the valeric acid and the like and the above R _1. Specific examples of the alcohol having 1 to 22 carbon atoms of R ₂ include methanol, ethanol, propanol,
Synthetic alcohols such as natural alcohols such as isopropanol, butanol, isobutanol, hexanol, 2-ethylhexanol, octanol, lauryl alcohol, palmityl alcohol, stearyl alcohol, isostearyl alcohol, hydroxystearyl alcohol, oleyl alcohol and behenyl alcohol, and oxo alcohols; Branched alcohols and the like can be mentioned.

Since the deinking agent of the present invention exhibits an excellent deinking effect even when used alone, a conventionally known deinking agent can be used in combination. Conventionally known deinking agents include, for example, higher alcohol sulfates, polyoxyalkylene higher alcohol sulfates, alkylbenzene sulfonates, fatty acids or salts thereof, higher alcohols or alkylphenol alkylene oxide adducts, fatty acid alkylene oxide adducts,
Fatty acid alkylene oxide adducts, mono-, di-, trialkylglyceride alkylene oxide adducts, polyhydric alcohol partial esters or complete ester alkylene oxide adducts, and the like can be mentioned.

[0025] Among these deinking agents, more excellent deinking performance is exhibited when used in combination with a fatty acid or a salt thereof, a higher alcohol and an alkylphenol alkylene oxide adduct.

The fatty acid or salt thereof used in combination has 8 carbon atoms.
~ 24 fatty acids or salts thereof, for example, caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid,
Oleic acid, coconut oil fatty acid containing behenic acid, etc. and their fatty acids, soybean oil fatty acid, rapeseed oil fatty acid, tall oil fatty acid, castor oil fatty acid, tallow fatty acid, palm oil fatty acid,
Examples include fish oil fatty acids and the like, and fatty acids and synthetic fatty acids obtained from natural products of hydrogenated products of those fatty acids. As the salt, a sodium salt and a potassium salt are preferable.

As the higher alcohol or alkylphenol alkylene oxide adduct to be used in combination, a compound represented by the following general formula (6) is particularly preferred. R ₃ —O— (YO) _p —H (6) (wherein, R ₃ is a linear or branched alkyl group or alkenyl group having 8 to 24 carbon atoms or an alkyl group having an alkyl group having 6 to 16 carbon atoms) Y is essential for ethylene oxide, and further includes propylene oxide and / or
Or a mixed alkylene oxide group to which butylene oxide has been added. p is an integer of 10 to 100, and the number of moles of ethylene oxide added is 40 to 80 mol% based on p. The compound represented by the general formula (6) is produced from a higher alcohol having a linear or branched alkyl or alkenyl group having 8 to 24 carbon atoms or an alkylphenol having an alkyl group having 6 to 16 carbon atoms. Examples of such higher alcohols include natural alcohols such as octanol, lauryl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol, and behenyl alcohol, and synthetic alcohols such as oxo alcohol. Examples of the alkyl phenol include octyl phenol, nonyl phenol, dodecyl phenol and the like. The compound represented by the general formula (6) is a compound obtained by blocking or random addition of a higher alcohol or an alkylphenol to ethylene oxide as an essential component and further to propylene oxide and / or butylene oxide. It is a compound having a mole number p of 10 to 100 moles and an addition mole number of ethylene oxide of 40 to 80 mole% based on the total mole number p of alkylene oxide addition.

The weight ratio of the compounds represented by the general formulas (1) to (5) to the fatty acid having 8 to 24 carbon atoms or a salt thereof and / or the compound represented by the general formula (6) is represented by the following formula: 1)
Any of the compounds represented by formulas (1) to (5)] / [fatty acids or salts thereof and / or compounds represented by formula (2)] =
90/10 to 10/90, particularly preferably 70/30 to 30/70.

When the deinking agent of the present invention is added to any of the steps, a higher quality deinked pulp can be obtained. Generally, the deinking agent is added to either the mixing step or the flotation step, or both. When dividedly added to each step, it can be added to each of the steps of pulping, kneading, dispersing, chemical mixing, and refining, but the division ratio of the deinking agent in the pre-step and the post-step is 10/90 to 90/10. (Weight ratio), particularly preferably 40/60 to 60/40 (weight ratio). The amount of the deinking agent added is desirably in an economical range without impairing the operability, but is preferably 0.03 to 1.0% by weight based on the raw waste paper.

[0030]

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

Example 1 This example is an example of batch addition of a deinking agent in a pulping step. After heat-recycled waste paper is cut into 2 x 5 cm pieces, a certain amount is put into a desktop disintegrator, and water and caustic soda (based on raw materials) are placed in it.
8% (by weight, the same applies hereinafter), sodium silicate (based on raw material) 2.
2%, 30% hydrogen peroxide solution (based on raw material) 3.5%, various deinking agents (based on raw material) 0.5% shown in Table 1 were added, and the pulp concentration was 15%.
%, 45 ° C, after 10 separations, diluted to 4% pulp concentration,
Then dehydrate to 25% with a high-speed dehydrator, 55 ℃, 120 minutes,
Aging treatment was performed at a pulp concentration of 25%. Then rotation speed 20
After kneading with a 0-rpm biaxial lab kneader, water was added to a pulp concentration of 4%, and defibration was performed for 3 minutes with a desktop disintegrator.
And subjected to flotation at 30 ° C for 10 minutes.
The foam removal property of the flotation reject was measured at the same time. Next, the pulp slurry after flotation was concentrated to a concentration of 20% with an 80 mesh wire, and water was added thereto to add 1%.
It was diluted to a concentration and a pulp sheet was prepared using a TAPPI sheet machine. The hardness of the used water was 5 ° dH, and the hardness was CaCl ₂ or MgCl ₂ , and Ca / M
It was adjusted so that g = 8/2 (molar ratio). The b value of the obtained pulp sheet was measured by a colorimeter (diffuse reflection type), and the area ratio (%) of the unstripped ink was determined by the following equation using an image analyzer (× 100). Table 1 shows the results.

[0032]

(Equation 1)

The heat-degraded waste paper referred to here is a blend of waste paper obtained by heat-treating the residual paper of offset newsprint at 80 ° C. for one month and a folded leaflet at a ratio of 80/20 (weight ratio) ( same as below). The bubble-removing property of the flotation reject refers to the foam scraped out after 3 minutes from the lab flotator, taken into a 2 liter cylinder, and measured immediately after (H ₀ ) and 1 minute later (H ₁ ). , Calculated by the following equation (the same applies hereinafter). The smaller H ₀ and H _{1 and the} larger the foam breaking rate, the better the bubble breaking.

[0034]

(Equation 2)

The b value is defined as Lab color difference formula Lab.
The b value in the color system is referred to, and the relationship with the tristimulus value XYZ is represented by the following expression. b = 7.0 (Y−0.847Z) / Y As can be seen from this equation, the b value is a function of Y and Z, where a positive value indicates yellowness and a negative value indicates bluish intensity.

In Table 1, EO means ethylene oxide, PO means propylene oxide, and BO means butylene oxide.
Among (AO) _m , those enclosed in [] mean that the alkylene oxide in [] was added at random, and the others are those with block addition (the same applies hereinafter).

Furthermore, in Table 1, "X _a O" corresponds to the general formula "X ₁ O""X ₃ O""X ₅ O""X ₇ O""X ₉ O '
And “X _b O” is “X ₂ O” corresponding to each general formula.
Any of “X ₄ O”, “X ₆ O”, “X ₈ O”, “X ₁₀ O”
“L” represents any one of l ₁ to l ₅ corresponding to each general formula,
“M” represents any one of m _{1 to} m ₅ corresponding to each general formula,
“N” means any of n _{1 to} n ₅ corresponding to each general formula. In general formula (2) described in the column of R ² of terminal hydrogen of convenience in the table to (5) (same in the following table).

[0038]

[Table 1]

Example 2 This example is an example of the divisional addition of the deinking agent in the pulping step and the chemical mixing step. After heat-recycled waste paper is cut into 2 x 5 cm pieces, a certain amount is put into a tabletop disintegrator, in which water and caustic soda (based on raw materials) are 0.2%, and various deinking agents shown in Table 2 (based on raw materials) are 0.1%. And defibrated for 15 minutes at 50 ° C at a pulp concentration of 5%, dehydrated to a pulp concentration of 18%, and contained 0.6% caustic soda (based on raw material) and sodium silicate (based on raw material).
2.2%, 30% hydrogen peroxide solution (based on raw material) 3.5%, various deinking agents (based on raw material) shown in Table 2 0.2%, and pulp concentration in water
The mixture was adjusted to 15% and mixed for 1 minute using a desktop disintegrator. 55 ℃,
The ripening treatment was performed at a pulp concentration of 15% for 120 minutes. Then, water was added to a pulp concentration of 4%, and the mixture was subjected to a defibration treatment for 3 minutes using a desktop disintegrator, further diluted with water to a pulp concentration of 1%, and subjected to a flotation treatment at 30 ° C. for 10 minutes. The foam removal property of the flotation reject was measured at the same time.
Next, the pulp slurry after the flotation was concentrated to a 6% concentration with an 80 mesh wire, and diluted with water to 1% concentration to prepare a pulp sheet using a TAPPI sheet machine. The hardness of the water used was 5 ° dH,
The hardness is CaCl ₂ , MgCl ₂ is used, and Ca / Mg =
It was adjusted to be 8/2 (molar ratio). The b value of the obtained pulp sheet is measured with a colorimeter (diffuse reflection type),
Further, the number area ratio (%) of the unstripped ink was determined in the same manner as described above using an image analyzer (× 100). Table 2 shows the results.

[0040]

[Table 2]

Example 3 This example is an example in which the deinking agent is added separately in the pulping step and the kneading step. After shredding the thermally degraded waste paper to 2 x 5 cm,
A certain amount was put into a tabletop disintegrator, and water and caustic soda (based on raw materials) 0.2% and various deinking agents (based on raw materials) 0.2% shown in Table 3 were added thereto. After defibration for a minute, dehydrate the pulp to a concentration of 28%, and add 0.6% caustic soda (based on raw material) and 2.2% sodium silicate (based on raw material).
%, 30% hydrogen peroxide solution (based on raw material) 3.5%, and various deinking agents (based on raw material) 0.2% shown in Table 3 were added.
%, And kneading treatment was performed by a biaxial lab kneader having a rotation speed of 200 rpm. After that, aging treatment is performed at 55 ° C for 120 minutes at a pulp concentration of 25%, and then a pulp concentration of 4%
Water, dilute it with a desktop disintegrator for 3 minutes, add water to dilute the pulp concentration to 1%, and apply a flotation treatment at 30 ° C for 10 minutes. Cutting performance was measured simultaneously. Next, the pulp slurry after flotation was treated with 80 mesh wire for 6 hours.
After concentrating to 1% concentration, add water to dilute to 1% concentration,
A pulp sheet was prepared using a PPI sheet machine. The hardness of the used water was 5 ° dH and the hardness was CaC
l ₂ and MgCl ₂ were used and adjusted so that Ca / Mg = 8/2 (molar ratio). The b value of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the unpeeled ink area ratio (%) was determined in the same manner as described above using an image analyzer (× 100). Table 3 shows the results.

[0042]

[Table 3]

Example 4 This example is an example of the divisional addition of the deinking agent before the pulping step and the flotation step. After heat-recycled waste paper is cut into 2 x 5 cm pieces, a certain amount is placed in a tabletop disintegrator, in which 0.2% of water and caustic soda (based on raw materials) and 0.2% of various deinking agents (based on raw materials) shown in Table 4 Was added, and the pulp concentration was 15%. The mixture was separated and disintegrated at 45 ° C for 12 minutes, and then aged at 55 ° C for 120 minutes. After that, dehydrate to 23% with a high-speed dehydrator, add caustic soda (based on raw material) 0.6%, sodium silicate (based on raw material) 2.2%, hydrogen peroxide (based on raw material) 3.5% and add pulp concentration 22% with water The mixture was adjusted and mixed for 1 minute using a table disintegrator. After that, the rotation speed 30
The kneading treatment was performed using a biaxial lab kneader at 0 rpm. Thereafter, water was added to dilute the pulp to a concentration of 4%, and the mixture was disintegrated again for 30 seconds using a desktop disintegrator. Thereafter, 0.2% of various deinking agents (based on raw materials) shown in Table 4 were added, diluted with water to 1%, and subjected to a flotation treatment at 30 ° C. for 10 minutes. Next, the pulp slurry after flotation was concentrated to a concentration of 4% with a 60 mesh wire, diluted with water to a concentration of 1% by adding water, and a pulp sheet was prepared with a tappy tandart paper machine. The hardness of the water used was 40 ° dH,
The hardness is CaCl ₂ , MgCl ₂ is used, and Ca / Mg =
It was adjusted to be 8/2 (molar ratio). The b value of the obtained pulp sheet is measured with a colorimeter (diffuse reflection type),
Further, the area ratio (%) of the unstripped ink was determined in the same manner as described above using an image analyzer (× 100). Table 4 shows the results.

[0044]

[Table 4]

Continuation of the front page (56) References JP-A-4-361678 (JP, A) JP-A-5-71086 (JP, A) JP-A-5-25790 (JP, A) JP-A-1-11756 (JP) JP-A-62-243892 (JP, A) JP-A-4-308289 (JP, A) JP-A-4-202885 (JP, A) JP-A-5-263379 (JP, A) 6-257085 (JP, A) JP-A-7-3681 (JP, A) JP-B-62-161711 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21C 5/02

Claims (11)

(57) [Claims] 1. A deinking agent comprising a compound represented by the following general formula (1). R ₁ —COO— (X ₁ O) ₁₁ — (AO) _m1 — (X ₂ O) _n1 —R ₂ (1) (wherein, R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms. Or an alkenyl group, R ₂ is a linear or branched alkyl group, alkenyl group or acyl group having 1 to 22 carbon atoms, X ₁ O and X ₂ O are propylene oxide and / or
Or butylene oxide, and l ₁ and n ₁ each represent 1 to
An integer of 50, m ₁ is an integer of 10 to 100, and l ₁ , m ₁ and n
The sum of ₁ is 12-120. AO is ethylene oxide alone or ethylene oxide and propylene oxide and / or
Alternatively, it is a polyoxyalkylene group obtained by block or random polymerization of butylene oxide. ) 2. The deinking agent according to claim 1, wherein both X ₁ O and X ₂ O are propylene oxide, and AO is ethylene oxide. 3. A deinking agent comprising a compound represented by the following general formula (2). R ₁ —COO— (X ₃ O) _l2 — (AO) _m2 — (X ₄ O) _n2 —H (2) (wherein R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms or X ₃ O and X ₄ O each represent propylene oxide, l ₂ is an integer of 1 to 20;
₂ is an integer of 51 to 100, n ₂ is an integer of 1 to 50, l ₂ ,
Total m ₂ and n ₂ is from 53 to 120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. ) 4. A deinking agent comprising a compound represented by the following general formula (3). R ₁ —COO— (X ₅ O) ₁₃ — (AO) _m3 — (X ₆ O) _n3 —H (3) (wherein R ₁ is a linear or branched alkyl group having 22 to 23 carbon atoms or X ₅ O and X ₆ O each represent propylene oxide, l ₃ is an integer of 1 to 20,
m ₃ is an integer of 10 to 50, n ₃ is an integer of 1 to 50, l ₃ ,
The sum of m ₃ and n ₃ is 12-120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. ) 5. A deinking agent comprising a compound represented by the following general formula (4). R ₁ —COO— (X ₇ O) ₁₄ — (AO) _m4 — (X ₈ O) _n4 —H (4) wherein R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms or X ₇ O and X ₈ O each represent propylene oxide, l ₄ is an integer of 21 to 50, and m is an alkenyl group.
₄ is an integer of 10 to 100; n ₄ is an integer of 1 to 50;
_4, the sum of m ₄ and n ₄ is from 32 to 120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. ) 6. A deinking agent comprising a compound represented by the following general formula (5). R ₁ —COO— (X ₉ O) ₁₅ — (AO) _m5 — (X ₁₀ O) _n5 —H (5) (wherein R ₁ is a linear or branched alkyl group having 7 to 23 carbon atoms or X ₉ O and X ₁₀ O are each propylene oxide and / or butylene oxide, at least one of which is butylene oxide, l ₅ and n ₅ are each an integer of 1 to 50, and m ₅ is an alkenyl group. 10-100
And the sum of l ₅ , m ₅ and n ₅ is from 12 to 120. AO is a polyoxyalkylene group obtained by block or random polymerization of ethylene oxide alone or ethylene oxide and propylene oxide and / or butylene oxide. ) 7. The method according to claim 1, wherein AO is ethylene oxide.
7. The deinking agent according to any one of items 6 to 6. 8. The deinking agent according to claim 1, wherein the number of moles of ethylene oxide added is 40 to 80 mol% based on the number of moles of all alkylene oxides added. 9. The deinking agent according to claim 1, further comprising a fatty acid having 8 to 24 carbon atoms or a salt thereof. 10. The deinking agent according to claim 1, further comprising a compound represented by the following general formula (6). R ₃ —O— (YO) _p —H (6) (wherein, R ₃ is a linear or branched alkyl group or alkenyl group having 8 to 24 carbon atoms or an alkyl group having an alkyl group having 6 to 16 carbon atoms) Y is essential for ethylene oxide, and further includes propylene oxide and / or
Or a mixed alkylene oxide group to which butylene oxide has been added. p is an integer of 10 to 100, and the number of moles of ethylene oxide added is 40 to 80 mol% based on p. ) 11. The weight ratio of any of the compounds represented by the general formulas (1) to (5) to the fatty acid having 8 to 24 carbon atoms or a salt thereof and / or the compound represented by the general formula (6) ,
[Any compound represented by the general formulas (1) to (5)]
/ [Fatty acid or salt thereof and / or compound represented by general formula (6)] = 90/10 to 10/90.
0 deinking agent.