JP2810538B2 - Deinking agent for recycled paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a deinking agent used for recycling used paper such as newspapers and magazines. More specifically, the present invention relates to a deinking agent capable of obtaining a deinked pulp having high whiteness and a small number of remaining inks when performing deinking treatment on newspapers, magazines and the like by a flotation method and a flotation / washing combination system.

[Problems to be solved by conventional technology and invention]

Recycling of newspapers, 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, as well as measures against garbage and protection of forest resources. It is taking on. In order to meet the growing needs, the use of deinked pulp and the development of advanced utilization technologies are being spurred. On the other hand, recently used paper has become even more rugged in terms of deinking due to changes in printing techniques, printing methods, and printing ink components.

Therefore, in order to further promote deinking, improvements have been made to the apparatus. For example, high-concentration aging treatment by installing a tower, introduction of a dispenser and a kneader for further promoting ink peeling by physical force, and installation of a high-concentration disintegrating pulper are also included. In addition, the introduction of a high-bubble type floatator has also become active in floatators.

Chemicals conventionally used to separate and remove ink and other impurities from waste paper include alkaline agents such as caustic soda, sodium silicate, sodium carbonate, and sodium phosphate, hydrogen peroxide, hyposulfite, and hypochlorous acid. Bleach such as salt, EDTA,
Along with sequestering agents such as DTPA, as deinking agents, anionic activators such as alkylbenzene sulfonates, higher alcohol sulfates, α-olefin sulfonates, dialkyl sulfosuccinates, higher alcohols, alkylphenols and fatty acids. Nonionic surfactants such as ethylene oxide adducts and alkanolamides have been used alone or in combination of two or more. However, these deinking agents have a high foaming property in the flotation treatment, but have a low ink collecting ability, and have a low detergency in the washing method, so that only low-quality deinked pulp can be obtained. Furthermore, even if a high whiteness is obtained, there is dullness, so the use of deinked pulp is restricted (reduction of the amount of paperboard used below and below, blending in newsprint, etc.) and bleaching to eliminate dullness. In this situation, the amount of the agent used had to be increased.

[Means for solving the problem]

The present inventors have developed a deinking agent for wastepaper recycling that exhibits excellent ink collecting ability in the flotation treatment process and can obtain deinked pulp having high whiteness, a low number of residual inks, and a small number of unstripped inks. As a result of intensive research to develop,
The present invention has been completed.

That is, the present invention provides a deinking agent for recycling used paper, comprising, as an active ingredient, a reaction product of a compound containing an OH group represented by the following (A), (B) or (C) and a monohalogen lower carboxylate. Is provided.

(A); a compound obtained by adding an average of 10 to 50 moles of ethylene oxide and propylene oxide to a hydroxy fatty acid having 5 to 24 carbon atoms in a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in total. B) an alcohol in which ethylene oxide and propylene oxide are added in an average of 10 to 50 mol per OH group so that the ratio of ethylene oxide / propylene oxide is 1 to 4 (molar ratio); Ester compound with 24 hydroxy fatty acids (C); an ester of a hydroxy fatty acid having 5 to 24 carbon atoms and an alcohol, wherein ethylene oxide and propylene oxide are in a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio). Average for each OH group in total
Compounds with 10 to 50 moles added The functions required for the deinking agent include the ability to lower the interfacial tension between cellulose and ink. The ability to prevent redeposition of ink peeled from cellulose. The high adsorption of ink to air bubbles. And four types of foam. A deinking agent must have these four functions in a well-balanced manner. The deinking agent for recycling waste paper of the present invention is excellent in the above, and can obtain deinked pulp having a small number of unstripped ink.

In the present invention, ethylene oxide and propylene oxide added to the OH group-containing compound used for obtaining the compound (A), (B) or (C) may be either block or random addition, but is preferably random addition. . The molar ratio of ethylene oxide to propylene oxide is ethylene oxide / propylene oxide = 1 to 4.
Is good, and preferably is in the range of 1-3. When the molar ratio is less than 1, the dispersing power of the ink detached from the cellulose is large, and the ability of forming a foam layer on the liquid level of the flotator is weak, so that the number of foam layers holding the ink is reduced. As a result, the whiteness decreases. Conversely, if the molar ratio is 4
If it is larger, the air bubble adsorbing property in the flotator is low, and as a result, the hue of the foam layer becomes whitish, indicating that the ink collecting property is low. Further, since the foam layer has a strong ability to form a foam layer on the liquid level of the flotator, the amount of froth foam is large. In addition, phenomena that are extremely problematic for operability, such as poor foaming properties in the frost pit, frequently occur.

The number of moles of ethylene oxide and propylene oxide added is preferably 10 to 50 moles on average per 1 active hydrogen atom. Preferably it is 20 to 35 mol. When the number of moles added is less than 10, the whiteness decreases because the ink releasability from cellulose and the ability to collect ink released from cellulose are small. On the other hand, if the number of added moles is larger than 50, the ability to form a foam layer on the flotator liquid surface is weakened, so that the foam layer that has collected the ink is not removed outside the system, and as a result, the whiteness is reduced. Having.

Examples of the hydroxy fatty acid having 5 to 24 carbon atoms used in the present invention include 12-hydroxystearic acid, 2-hydroxybehenic acid, 2-hydroxyundecanoic acid, di-3-hydroxylauric acid, and tetra-3-hydroxytridecanoic acid , 12-oxyoleic acid and the like.

In the present invention, examples of the alcohol to be reacted with the hydroxy fatty acid include a monovalent alkyl or alkenyl alcohol having 1 to 24 carbon atoms or a polyhydric alcohol. Examples of the monohydric alcohol include lower alcohols such as methanol and ethanol, and higher alcohols such as fatty acid alcohols. As the polyhydric alcohol, a dihydric alcohol or a sugar alcohol is preferably used. Examples of the dihydric alcohol include ethylene glycol, propylene glycol, butanediol, and the like. Examples of the sugar alcohol include sorbitol and pentaerythritol. In addition to these, glycerin, trimethylolpropane and the like can be mentioned as trihydric alcohols. In the present invention, the ester of a C5-24 hydroxy fatty acid and an alcohol includes castor oil and hardened castor oil containing these.

In the present invention, the reaction ratio between the compounds (A) to (C) and the monohalogen lower carboxylate is determined by the ratio of the compounds (A) to
It is preferable to use 0.8 to 1.2 moles of the monohalogen lower carboxylate per one residual OH group of (C). If (A), (B) or (C) is extremely large with respect to this charging ratio, the whiteness may be reduced because the ink collecting ability in the rotator is reduced. In the opposite case, that is, when the amount of monohalogenated lower carboxylate is extremely large, the ink peeling property from cellulose is small, so that the amount of unstripped ink increases, and only deinked pulp with poor appearance can be obtained.

Examples of the monohalogenated lower carboxylate used in the present invention include sodium salts and potassium salts of monochloroacetic acid, monobromoacetic acid, monochloropropionic acid, monobromopropionic acid and the like.

The method for producing the deinking agent for recycling waste paper of the present invention is not particularly limited, and the method (A), (B) or (C) described above may be used.
And a monohalogenated lower carboxylate are mixed and heated and reacted in an alkaline atmosphere to produce the compound. For example, the production method described in JP-B-54-4932 corresponds to this.

The deinking agent for recycling waste paper of the present invention may be added to any of the waste paper disintegration step, the kneader treatment step, the aging tower step and the flotation treatment or to each step, but the most effective is the case where it is added to the waste paper disintegration step. Is high. The amount of addition is preferably 0.05 to 1.0% by weight based on the raw waste paper.

Further, the deinking agent for reclaiming used paper of the present invention can be used in combination with a known deinking agent generally used conventionally.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Production Example 1 Ethylene oxide (hereinafter referred to as 12-hydrocystearic acid)
Equipped with a stirring rod, a thermometer, a dropping funnel and a Claisen tube equipped with 46,6 g of a compound obtained by block addition of 20 molar equivalents of EO) and 10 molar equivalents of propylene oxide (hereinafter, referred to as PO) and sodium monochloroacetate. 4 mouths 1
Charge the reaction flask, and stir well, with the reaction temperature 80 ~
While maintaining a reduced pressure of 50 mm / Hg at 85 ° C., 9.5 g of NaOH is added dropwise as a 48% aqueous solution over 1 hour. The water distilled at this time is condensed by the cooler and removed to the outside of the system. Thereafter, the reaction is carried out for 2 hours under the same conditions to complete the reaction.

Production Example 2 Polyoxyethylene di-3-hydroxylaurate (hereinafter abbreviated as POE) polyoxypropylene (hereinafter abbreviated as POP) trimethylolpropane ester (EO = 60 mol,
PO = 50 moles, here means the average number of moles added.
The same applies hereinafter) 488.8 g, sodium monochloroacetate 8.3 g and
The reaction was carried out by performing the same operation as in the production example using 2.9 g of NaOH as a 40% aqueous solution.

Production Example 3 The same operation as in Production Example 1 was carried out using 441.6 g of a compound obtained by randomly adding EO = 50 mol and PO = 30 mol to hydrogenated castor oil, 47.6 g of sodium monobromopropionate and 10.9 g of NaOH as a 40% aqueous solution. And reacted.

Example 1 A used newspaper collected in the market was shredded to 2 × 5 cm, and a certain amount of the waste paper was put into a table disintegrator, in which water and caustic soda (based on raw material) were 1.0% (weight basis, the same applies hereinafter), sodium silicate ( 3.0%, 30% hydrogen peroxide water (based on raw material) 3.0%, Table-1
After adding 0.4% of various deinking agents (based on raw materials) shown in (1), the pulp concentration was 5%, the mixture was separated at 55 ° C for 20 minutes, and then ripened at 50 ° C for 60 minutes. Then, water was added to dilute the pulp concentration to 1.0%, and CaC
l ₂ (based on raw material) was added, and flotation treatment was performed at 30 ° C. for 10 minutes. The pulp slurry after flotation was concentrated to a 6% concentration, and then diluted to 1% concentration by adding water, and a pulp sheet was prepared using a TAPPI sheet machine.
The whiteness of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured with an image analyzer (× 100). Further, the height of the foam layer on the flotator liquid surface (at 3 minutes) was also measured.

 Table 2 shows the results.

Example 2 The used newspaper collected in the market was shredded to 2 × 5 cm, and a certain amount was put into a table disintegrator, in which water and caustic soda (based on raw material) were 1.0%, and sodium silicate 3 (based on raw material) was 0.5%. And 0.4% of various deinking agents (based on raw materials) shown in Table 3 were added. The pulp concentration was 5%, and after 45 minutes at 45 ° C, the pulp was dehydrated so that the pulp concentration became 18%. 1.5% for raw material, 2.5% for sodium silicate (for raw material), 30% aqueous hydrogen peroxide (for raw material) 3.0
After adding and mixing, the pulp concentration is 15% at 55 ° C for 90 minutes.
For aging treatment. Then, water was added to a pulp concentration of 4%, and the mixture was subjected to a defibration treatment for 5 minutes using a desktop disintegrator. Further, water was added to dilute the pulp concentration to 1.0%, and CaCl ₂ (based on raw material) was added.
1.0% was added, and a flotation treatment was performed at 30 ° C. for 10 minutes. The pulp slurry after flotation was concentrated to a 6% concentration, and then diluted to 1% concentration by adding water, and a pulp sheet was prepared using a TAPPI sheet machine. The whiteness of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured with an image analyzer (× 100). Further, the height of the foam layer on the flotator liquid surface (at 3 minutes) was also measured.

 Table 4 shows the results.

Example 3 A city-collected magazine was cut into 2 × 5 cm pieces, and a certain amount was placed in a tabletop disintegrator, in which water and caustic soda (based on raw materials) were added.
5%, sodium silicate (based on raw material) 1.5%, 30% hydrogen peroxide (based on raw material) 1.0%, and a deinking agent (based on raw material) 0.05% shown in Table 5 are added. Separation solution processing was performed.
Then add water to this to dilute the pulp concentration to 4.0%,
Then, water was further added to bring the pulp concentration to 1.0%. This was subjected to a flotation treatment at 30 ° C. for 10 minutes. After the pulp slurry after the flotation was concentrated to a 6% concentration, water was added to dilute the pulp slurry to a 1.0% concentration to prepare a pulp sheet using a TAPPI sheet machine.

The whiteness of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured with an image analyzer (× 100). In addition, the height of the foam layer on the flotator liquid surface (after 3 minutes) was also measured.

 The results are shown in Table-6.

From Table-2, Table-4 and Table-6, according to the used paper recycling deinking agent of the present invention, whiteness is high, the number of remaining inks is small,
In particular, high quality deinked pulp having a small number of unstripped inks can be obtained. In addition, the foam height, which is an index of the operability of the flotator, is also appropriate.

Claims (3)

(57) [Claims] (1) Represented by the following (A), (B) or (C)
A deinking agent for recycling used paper, which comprises, as an active ingredient, a reaction product of a compound containing an OH group and a monohalogen lower carboxylate. (A); a compound obtained by adding an average of 10 to 50 mol of ethylene oxide and propylene oxide to a hydroxy fatty acid having 5 to 24 carbon atoms in a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in total. B) an alcohol obtained by adding an average of 10 to 50 moles of ethylene oxide and propylene oxide so as to have a ratio of ethylene oxide / propylene oxide of 1 to 4 (molar ratio) per OH group; Ester compound with hydroxy fatty acid of 24 (C); ester of hydroxy fatty acid having 5 to 24 carbon atoms and alcohol, ethylene oxide and propylene oxide being ethylene oxide / propylene oxide = 1 to 4 (molar ratio)
The average is 10 to 10 per OH group in total so that the ratio of
Compound with 50 moles added 2. The method according to claim 1, wherein 0.8 to 1.2 mol of a monohalogen lower carboxylate is used per residual OH group of the compound (A), ester (B) or compound (C). Black ink. 3. The deinking agent according to claim 1, wherein the alcohol is a monovalent alkyl or alkenyl alcohol having 1 to 24 carbon atoms or a polyhydric alcohol.