JP2022001686A - Deinking agent composition and method of producing recycled pulp - Google Patents

Abstract

To provide a deinking agent composition enhanced in deinking effects in view of solving a problem that conventional deinking agent compositions, although effective regarding vegetable oil ink used in newspaper or the like, have not necessarily satisfactory deinking effects regarding active energy ray-curable ink, inkjet ink, toner, etc.SOLUTION: The deinking agent composition includes a specified nonionic surface active agent (A) and another specified nonionic surface active agent (B), and may include fatty acid or salt thereof (C), in which a mass ratio expressed in (A) component/(B) component is 60/40 to 99/1 and a mass ratio expressed in ((A) component + (B) component)/(C) is 40/60 to 100/0.SELECTED DRAWING: None

Description

The present invention relates to a deinking agent composition and a method for producing recycled pulp.

It has been practiced for a long time to manufacture recycled pulp from raw material waste paper including used printing paper such as newspaper paper, information paper, and copy OA paper, and use it as a raw material for papermaking again. In recent years, from the viewpoint of effective use of resources and environmental protection, the recycling of used raw paper has become more important, and the use of recycled pulp has also expanded.

The method for producing recycled pulp (method of deinking raw recycled paper) is generally a decoupling step in which an alkaline agent, a surfactant, etc. are added to the raw recycled paper to peel off the ink, and an ink removal method for removing the peeled ink from the pulp slurry. Including the process. The ink removal process is roughly divided into a cleaning method and a flotation method.
The cleaning method is a method in which the pulp slurry is repeatedly diluted and dehydrated, or the peeled ink is separated from the pulp slurry by using a cleaning device such as a screen or a centrifugal cleaner. The cleaning method requires a large amount of water, which is disadvantageous in terms of resource saving and energy saving.
In the flotation method, air is blown into the pulp slurry using a floatator, the ink that has peeled off is adsorbed on the generated bubbles and floated, and the bubbles (fross) formed by the gathering of bubbles are discharged and removed from the system. , A method of separating pulp and ink. The flotation method is advantageous in terms of resource saving and energy saving because it requires less water to be used.

In the deinking method for removing the exfoliated ink by the flotation method, a deinking agent composition is used. The deinking agent composition is used at least at the timing when flotation is performed, but it may be added to the raw material used paper from the time of the dissociation step.
The deinking agent composition is required to have appropriate foaming property in flotation and high ink collecting property (adsorption property of ink to bubbles). Further, as described above, since the deinking agent composition may be added to the raw material used paper from the time of the dissociation step and used, the deinking agent composition is also required to have excellent ink peeling property in the decoupling step. Be done. That is, the deinking agent composition is required to remove ink from the raw material used paper to increase the whiteness of the recycled pulp (deinking effect).
In addition, due to the diversification of used raw paper, the amount of various foreign substances (dirt) such as hydrophobic organic resins in pulp and adhesives (also called sticky) such as binders in the inorganic pigment coating layer has increased. ing. Therefore, these foreign substances may remain in the recycled pulp as black spot stains that can be visually identified, which may cause a problem. Therefore, the deinking agent composition is also required to remove foreign substances.

As the deinking agent composition, a nonionic surfactant in which an alkylene oxide is added to a higher alcohol is widely used (for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 07-11960 JP-A-2015-196932 Japanese Unexamined Patent Publication No. 2017-666570

However, although the conventional deinking agent composition is effective for vegetable oil inks used in newspapers and the like, the deinking effect on active energy ray-curable inks, inkjet inks, toners and the like is not always satisfactory. I didn't.
The present invention has been made in view of the above circumstances, and an object of the present invention is a deinking agent composition capable of further enhancing the deinking effect.

The present invention has the following aspects.
<1>
Component (A): a nonionic surfactant represented by the following formula (a) and component (B): a nonionic surfactant represented by the following formula (b), and component (C): It may contain a fatty acid having 12 to 24 carbon atoms or a salt thereof.
The mass ratio represented by the component (A) / the component (B) is 60/40 to 99/1.
A deinking agent composition having a mass ratio represented by (the component (A) + the component (B)) / the component (C) of 40/60 to 100/0.
R ¹ −O− [(EO) _m / (PO) _n ] −H ・ ・ ・ (a)
In the formula (a), R ¹ is an alkyl group or an alkenyl group having 14 to 24 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and m represents the average number of repetitions of EO. It is a number of ~ 80, and n is a number of 4 to 60 representing the average number of repetitions of PO. (EO) _m / (PO) _n means that there is no limitation on the addition form of EO and PO. )
R ^2- O- (EO) _x- H ... (b)
(B) In the formula (b), R ² is an alkyl group having 10 to 14 carbon atoms. EO represents an ethyleneoxy group. X is a number of 8 to 20 representing the average number of repetitions of EO.)
<2>
The component (A) is selected from the group consisting of a component (A1): a nonionic surfactant represented by the following formula (a1) and a component (A2): a nonionic surfactant represented by the following formula (a2). The deinking agent composition according to <1>, which is at least one kind.
R ^11- O- (PO) _t- (EO) _u- (PO) _v- H ... (a1)
In the formula (a1), R ¹¹ is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and t represents the average number of repetitions of PO 1. It is a number of 10 to 10, u is a number of 10 to 40 representing the average number of repetitions of EO, and v is a number of 3 to 40 representing the average number of repetitions of PO.)
R ^12- O- (PO) _p -[(EO) _q / (PO) _r ]-(PO) _s- H ... (a2)
In the formula (a2), R ¹² is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and p represents the average number of repetitions of PO 1. It is a number of 10 to 10, q is a number of 31 to 60 representing the average number of repetitions of EO, r is a number of 1 to 15 representing the average number of repetitions of PO, and s represents the average number of repetitions of PO. It is a number of 3 to 30. (EO) _q / (PO) _r means that there is no limitation on the addition form of EO and PO.)
<3>
It contains the component (C) and contains
The deinking agent composition according to <1> or <2>, wherein the mass ratio represented by (the component (A) + the component (B)) / the component (C) is 45/55 to 95/5. thing.
<4>
In a method for producing recycled pulp, which is obtained by peeling ink from raw material waste paper and removing the peeled ink to obtain recycled pulp.
A method for producing recycled pulp, which comprises a step of performing a deinking treatment on raw material used paper in the presence of the deinking agent composition according to any one of <1> to <3>.

According to the deinking agent composition of the present invention, the deinking effect can be further enhanced.

(Deinking agent composition)
The deinking agent composition of the present invention may contain the following component (A), the following component (B), and the following component (C).
The dosage form of the deinking agent composition may be a liquid or a solid such as a powder. In the deinking agent composition, all of the constituents may be integrated (integral type), or some or all of the constituents may be independent (separate type).

<Ingredient (A)>
The component (A) is a nonionic surfactant represented by the following formula (a). By containing the component (A), the deinking agent composition can enhance the deinking effect on used printed paper such as newspapers and leaflets. Penetration-drying inks, oxidative polymerization inks, and the like are used for newspapers, leaflets, and the like. These inks contain vegetable oils, which are drying or semi-drying oils. Examples of vegetable oils that are drying oils or semi-drying oils include flaxseed oil and soybean oil.

R ¹ −O− [(EO) _m / (PO) _n ] −H ・ ・ ・ (a)
In the formula (a), R ¹ is an alkyl group or an alkenyl group having 14 to 24 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and m represents the average number of repetitions of EO. It is a number of ~ 80, and n is a number of 4 to 60 representing the average number of repetitions of PO. (EO) _m / (PO) _n means that there is no limitation on the addition form of EO and PO. )

The carbon number of R ¹ is 14 to 24, preferably 16 to 22, and more preferably 16 to 20. When the number of carbon atoms is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
R ¹ may be a straight chain or a branched chain. R ¹ may be a primary hydrocarbon group or a secondary hydrocarbon group.

m is 4 to 80, preferably 10 to 60, and more preferably 14 to 50. When m is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
n is 4 to 60, preferably 8 to 50. When n is within the above range, the deinking effect of the deinking agent composition can be further enhanced.

The (EO) _m / (PO) _n may be block addition or random addition. The additional form of EO and PO is not limited.

Among the components (A), the nonionic surfactant represented by the following formula (a1) (component (A1)) and the nonionic surfactant represented by the following formula (a2) (component (A2)) are preferable. With these components (A), the deinking effect can be further improved.

R ^11- O- (PO) _t- (EO) _u- (PO) _v- H ... (a1)
In the formula (a1), R ¹¹ is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and t represents the average number of repetitions of PO 1. It is a number of 10 to 10, u is a number of 10 to 40 representing the average number of repetitions of EO, and v is a number of 3 to 40 representing the average number of repetitions of PO.)

The carbon number of R ¹¹ is preferably 16 to 22, more preferably 16 to 20, and even more preferably 16 to 18. When the number of carbon atoms is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
R ¹¹ may be a straight chain or a branched chain. R ¹¹ may be a primary hydrocarbon group or a secondary hydrocarbon group.

t is preferably 1 to 10, more preferably 1 to 8, and even more preferably 2 to 7. When t is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
u is preferably 10 to 40, more preferably 14 to 38, and even more preferably 16 to 36. When u is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
v is preferably 3 to 40, more preferably 5 to 36, and even more preferably 8 to 32. When v is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
The total (t + v) of t and v is more preferably 8 to 40, and even more preferably 10 to 36. When t + v is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
The total (t + u + v) of t, u, and v is more preferably 22 to 80, and even more preferably 26 to 74. When t + u + v is within the above range, the deinking effect of the deinking agent composition can be further enhanced.

R ^12- O- (PO) _p -[(EO) _q / (PO) _r ]-(PO) _s- H ... (a2)
In the formula (a2), R ¹² is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and p represents the average number of repetitions of PO 1. It is a number of 10 to 10, q is a number of 31 to 60 representing the average number of repetitions of EO, r is a number of 1 to 15 representing the average number of repetitions of PO, and s represents the average number of repetitions of PO. It is a number of 3 to 30. (EO) _q / (PO) _r means that there is no limitation on the addition form of EO and PO.)

The carbon number of R ¹² is preferably 16 to 22, more preferably 16 to 20, and even more preferably 16 to 18. When the number of carbon atoms is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
R ¹² may be a straight chain or a branched chain. R ¹² may be a primary hydrocarbon group or a secondary hydrocarbon group.

p is more preferably 1 to 8 and even more preferably 2 to 7. When p is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
q is more preferably 32 to 56, and even more preferably 34 to 52. When q is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
r is more preferably 2 to 13 and even more preferably 3 to 11. When r is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
The s is more preferably 5 to 28, and even more preferably 7 to 26. When s is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
The total of p, r and s (p + r + s) is more preferably 9 to 48, still more preferably 13 to 42. When p + r + s is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
The total (p + q + r + s) of p, q, r and s is more preferably 40 to 102, and even more preferably 47 to 94. When p + q + r + s is within the above range, the deinking effect of the deinking agent composition can be further enhanced.

(EO) _q / (PO) _r may be a block addition or a random addition. The additional form of EO and PO is not limited. Among them, (EO) _q / (PO) _r is preferably randomly added. If it is randomly added, the deinking effect can be further improved.

The component (A) may be a commercially available product or a synthetic product.
The method for synthesizing the component (A) is not particularly limited, and a conventionally known synthesis method can be appropriately selected. As a method for synthesizing the component (A), for example, an alcohol having an alkyl group or an alkenyl group having a target carbon number, an amount of EO corresponding to the target average number of repetitions, and a target average number of repetitions are equivalent. Examples thereof include a method of reacting an amount of PO in the presence of a catalyst.

These components (A) may be used alone or in combination of two or more.

The content of the component (A) is appropriately determined according to the dosage form and the like of the deinking agent composition. The content of the component (A) is, for example, preferably 39 to 99% by mass, more preferably 45 to 94% by mass, still more preferably 50 to 87% by mass, based on the total mass of the deinking agent composition. When the content of the component (A) is at least the above lower limit value, the content of the component (A) in the deinking agent composition is increased, and the deinking effect of the deinking agent composition can be further improved. When the content of the component (A) is not more than the above upper limit value, the content of other components can be increased to further improve the deinking effect of the deinking agent composition.

<Ingredient (B)>
The component (B) is a nonionic surfactant represented by the following formula (b). By containing the component (B), the deinking agent composition can enhance the deinking effect on the printed waste paper discharged from offices and homes. Printed matter printed in the office or at home includes printed matter printed using inkjet ink, printed matter using active energy ray-curable ink such as UV curable ink, printed matter using toner, and printed matter using a laser printer. And so on.

R ^2- O- (EO) _x- H ... (b)
(B) In the formula (b), R ² is an alkyl group having 10 to 14 carbon atoms. EO represents an ethyleneoxy group. X is a number of 8 to 20 representing the average number of repetitions of EO.)

The number of carbon atoms of R ² is, 10 to 14 is preferred. When the number of carbon atoms is within the above range, the deinking effect of the deinking agent composition can be further enhanced.
R ² may be a straight chain or a branched chain. R ² can be a primary hydrocarbon group or a secondary hydrocarbon group.

x is preferably 8 to 20, more preferably 10 to 18. When x is within the above range, the deinking effect of the deinking agent composition can be further enhanced.

The component (B) may be a commercially available product or a synthetic product.
Commercially available products of the component (B) include Leocol SC70, Leocol SC90, Leocol SC120, Leocol TD90, Leocol TD120, Emulsifier TD150 (all manufactured by Lion Specialty Chemicals), EMALEX709, EMALEX710, EMALEX712, EMALEX715, EMALEX720 (or more). , Nippon Emulsion), Neugen XL-70, Neugen XL-80, Neugen XL-100, Neugen XL-140, Neugen XL-160 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Pegnor L-9A, Pegnor TE- Examples thereof include 10A (above, manufactured by Toho Chemical Industry Co., Ltd.), Newcol 1300 series (above, manufactured by Nippon Emulsifier Co., Ltd.) and the like.
Examples of the method for synthesizing the component (B) include the same synthesis method as for the component (A).

The above-mentioned component (B) may be used alone or in combination of two or more.

The content of the component (B) is appropriately determined according to the dosage form and the like of the deinking agent composition. The content of the component (B) is preferably, for example, 1 to 40% by mass, more preferably 2 to 35% by mass, still more preferably 3 to 30% by mass, based on the total mass of the deinking agent composition. When the content of the component (B) is at least the above lower limit value, the content of the component (B) in the deinking agent composition is increased, and the deinking effect of the deinking agent composition can be further improved. When the content of the component (B) is not more than the above upper limit value, the content of other components can be increased to further improve the deinking effect of the deinking agent composition.

In the deinking agent composition, the mass ratio represented by the component (A) / the component (B) (that is, the mass ratio of the component (A) to the component (B)) is 60/40 to 99/1. 70/30 to 98/2 is preferable, and 75/25 to 97/3 is more preferable. If the mass ratio (A / B ratio) represented by the component (A) / component (B) is within the above range, the deinking effect can be further improved.

<Ingredient (C)>
The deinking agent composition may contain the component (C).
The component (C) is a fatty acid having 12 to 24 carbon atoms or a salt thereof, and is a so-called higher fatty acid (salt). By containing the component (C) in the deinking agent composition, dirt can be satisfactorily removed and the yield of regenerated pulp can be increased.

The component (C) is represented by the following formula (c).

R ^3- COOH ・ ・ ・ (c)
(R ³ is an aliphatic hydrocarbon group having 11 to 23 carbon atoms.)

The ^{number of carbon atoms of R 3} is 11 to 23, preferably 13 to 19. That is, the carbon number of the component (C) is 12 to 24, preferably 14 to 20. When the number of carbon atoms is at least the above lower limit value, the peeled ink can be better collected in the flotation step described later. When the number of carbon atoms is not more than the above upper limit value, the liquid can be maintained at a low temperature (50 ° C. or less), so that it can be easily used. In addition, when the number of carbon atoms is not more than the above upper limit value, the foreign matter can be removed more satisfactorily in the flotation step described later. The "carbon number of the component (C)" referred to here also includes carbon of -COOH.
R ³ may be a straight chain or a branched chain. When R ³ is linear, R ³ may be a primary hydrocarbon group or a secondary hydrocarbon group.

The iodine value of the component (C) is preferably 50 to 150, more preferably 60 to 140, and even more preferably 60 to 120. When the iodine value of the component (C) is at least the above lower limit value, the foreign matter can be removed more satisfactorily. When the iodine value of the component (C) is not more than the upper limit value, the deinking effect can be further improved and the foreign matter can be removed more satisfactorily.
The iodine value of the component (C) tends to increase as the content of the unsaturated fatty acid in the component (C) increases. Therefore, it is preferable to adjust the amount of unsaturated fatty acid described later so that the iodine value is within the above range.
In the present invention, the iodine value of the component (C) is measured according to the Wies-cyclohexane method (2.3.4.1-1996 of the standard fat analysis test method). When a neutralized product of the mixed fatty acid is used as the component (C), the iodine value of the component (C) is the iodine value of the mixed fatty acid before neutralization.

The salt constituting the component (C) can be appropriately selected depending on the intended purpose, and examples thereof include alkali metals, alkaline earth metals, and organic amines. Examples of the alkali metal include sodium and potassium. Examples of the alkaline earth metal include calcium and magnesium, and examples of the organic amine include methylamine, ethylamine and diethanolamine. Among them, as the salt constituting the component (C), an alkali metal is preferable, and sodium and potassium are more preferable, from the viewpoint of cost and odor reduction.

The component (C) may be any of a saturated fatty acid and a salt thereof, an unsaturated fatty acid and a salt thereof.
The component (C), for example, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid (or, R ³ is a primary saturated hydrocarbons), 2-hexyldecanoate Generic name: iso Palmitic acid], 2- (4,4-dimethyl-2-pentyl) -5,7,7-trimethyl-n-octanoic acid [general name: isostearic acid], 2-heptylundecanoic acid [general purpose name: isostearic acid] , 2- (4Methyl-1-hexyl) -8-methyl-n-decanoic acid [general name: isostearic acid], 2-octyldecanoic acid [general purpose name: isostearic acid], 2- (i-octyl) -i -Saturated fatty acids such as dodecanoic acid [generic name: isoeicosanoic acid] and salts thereof, cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid, 9,12,15-octadecanthrionic acid, cis- Examples thereof include unsaturated fatty acids such as 13-docosenoic acid and salts thereof.
As the component (C), for example, NAA series, RNF series (above, manufactured by NOF Corporation), TFA series (above, manufactured by Tsukino Food Industry Co., Ltd.) and the like can also be used.
These components (C) may be used alone or in combination of two or more.

As the component (C), R ³ is a linear and secondary hydrocarbon or a branched chain hydrocarbon (C1), and R ³ is a linear and primary hydrocarbon (C2). It is preferable to contain both of the components. By containing both the component (C1) and the component (C2), the deinking effect can be further improved and the foreign matter can be removed more satisfactorily.
When the deinking agent composition contains both the (C1) component and the (C2) component, the mass ratio represented by the (C1) component / (C2) component (that is, the (C1) component with respect to the (C2) component). The mass ratio) is preferably 3/97 to 90/10, more preferably 5/95 to 80/20, and even more preferably 5/95 to 60/40. When the mass ratio (C1 / C2 ratio) represented by the component (C1) / component (C2) is within the above range, the deinking effect can be further improved and foreign matter can be removed more satisfactorily.

The content of the component (C) is preferably 0 to 60% by mass, more preferably 4 to 50% by mass, still more preferably 10 to 40% by mass, based on the total mass of the deinking agent composition. When the content of the component (C) is at least the above lower limit value, the content of the component (C) is increased, the deinking effect can be further improved, and foreign matter can be removed more satisfactorily. When the content of the component (C) is not more than the above upper limit value, the contents of the component (A) and the component (B) are increased, and the deinking effect can be further improved.

The mass ratio represented by ((A) component + (B) component) / (C) component (that is, the mass ratio of the total amount of the (A) component and the (B) component to the (C) component) is 40. It is preferably / 60 to 100/0, more preferably 45/55 to 95/5, and even more preferably 50/50 to 90/10. When the mass ratio ((A + B) / C ratio) represented by ((A) component + (B) component) / (C) component is at least the above lower limit value, the deinking effect can be further enhanced. When the (A + B) / C ratio is not more than the above upper limit value, the foreign matter can be removed more satisfactorily.

The total amount of the components (A) to (C) is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, still more preferably 70 to 100% by mass, based on the total mass of the deinking agent composition. .. If the total amount of the components (A) to (C) is within the above range, the deinking effect can be further improved.

<Arbitrary ingredient>
In the method for producing recycled pulp described later, the deinking agent composition is used in combination with an alkaline agent, a bleaching agent, a chelating agent and the like. Therefore, the deinking agent composition of the present invention may contain an alkaline agent, a bleaching agent, a chelating agent and the like as optional components as long as the effect is not impaired.
Examples of the alkaline agent include alkali metal salts such as sodium hydroxide (sodium carbonate), sodium carbonate (sodium carbonate), and sodium silicate (sodium silicate).
Examples of the bleaching agent include hydrogen peroxide and sodium hypochlorite.
Examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentacetic acid (DTPA).

The deinking agent composition of the present invention may contain a surfactant (arbitrary surfactant) other than (A) to (C). Examples of the optional surfactant include surfactants conventionally used as a deinking agent composition, for example, alkylbenzene sulfonate, α-olefin sulfonate, higher (8 to 22 carbon atoms) alcohol sulfate. Examples thereof include anionic surfactants such as ester salts and dialkyl sulfosuccinates, and nonionic surfactants composed of alkylene oxide adducts such as alkanol amide.
The total amount of the surfactant (including the components (A) to (C)) is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, and 70 to 70 to the total mass of the deinking agent composition. 100% by mass is more preferable. When the total amount of the surfactant is within the above range, the deinking effect can be further improved and the transportation efficiency can be improved.

The deinking agent composition of the present invention may contain a dispersion medium such as water or alcohol. Examples of the alcohol as the dispersion medium include methanol, ethanol, isopropyl alcohol and the like.
The above-mentioned optional components may be used alone or in combination of two or more.
The total amount of the components (A) to (C) and the optional components does not exceed 100% by mass.

The method for producing a deinking agent composition of the present invention is such that the components (A) to (C) and, if necessary, the component (C) are mixed or not mixed to obtain a deinking agent composition. good.
For example, as a method for producing an integrated deinking agent composition, a method of mixing the components (A) to (C) and an arbitrary component and molding them into an arbitrary shape to obtain a solid deinking agent composition is used. Can be mentioned. Further, as a method for producing an integrated deinking agent composition, a method of dispersing the components (A) to (C) and an arbitrary component in a dispersion medium to obtain a liquid deinking agent composition can be mentioned.

(Manufacturing method of recycled pulp)
The method for producing recycled pulp of the present invention includes a step of deinking the raw recycled paper in the presence of the deinking agent composition.
The method for producing recycled pulp of the present invention will be described with reference to one embodiment.
The method for producing recycled pulp of the present embodiment is a method in which ink is peeled from the raw material waste paper (dissolution step) and the peeled ink is removed by a flotation method (floatation step) to obtain recycled pulp. In this embodiment, the flotation step is an ink removing step.
The method for producing recycled pulp of the present embodiment preferably includes a disintegration step and a flotation step in this order, and further includes other steps as necessary.
In the method for producing recycled pulp of the present embodiment, the deinking treatment comprises a deinking step and a flotation step.

The deinking agent composition of the present invention may be used at least at the timing when the flotation step is performed. The timing of adding the deinking agent composition into the system may be added from the time of the dissociation step, may be added from the time of the flotation step, or may be added at both the dissociation step and the flotation step. You may. Since the deinking agent composition of the present invention is excellent in ink removing property and foreign matter removing property, it is preferable to add the deinking agent composition of the present invention from the time of the dissociation step.
When the deinking agent composition contains the component (C) and an optional component, each component may be added to the pulp slurry described later in a state of being mixed in advance, or each component may be added to the pulp slurry separately. May be good.

<Dissociation process>
The dissociation step is a step of dissociating the raw material waste paper into fibrous pulp and peeling ink from the pulp.
The method for peeling the ink from the raw material used paper is not particularly limited, but for example, an agent other than the deinking agent composition of the present invention (hereinafter, also referred to as “another agent”) is added to the raw material used paper, and further desired. Examples thereof include a method of adding water so as to have a solid content concentration of 1 and stirring the mixture. When the deinking agent composition of the present invention is added from the time of the dissociation step, the deinking agent composition is added to the raw material used paper before or after the addition of the other agent, or at the same time as the other agent.
Hereinafter, a suspension containing at least raw material waste paper, other chemicals, and water is referred to as "pulp slurry".

The raw material used paper is not particularly limited as long as it contains paper printed with ink (printed used paper), and can be appropriately selected according to the purpose. The raw material used paper may be coated paper or uncoated paper.
Specific examples of the raw material used paper include newspaper (neutral newspaper, acidic newspaper, etc.), magazine paper, information paper, leaflet paper, imitation paper, copy OA used paper (copy, computer output, etc.) and the like. The ink of the used printing paper is not particularly limited, and examples thereof include vegetable oil ink, inkjet ink, active energy ray-curable ink such as UV curable ink, toner, and toner for a laser printer.
These printed waste papers may be used alone or in combination of two or more.
The raw material used paper including the printed used paper may be used as it is, or may be pretreated by appropriately combining cutting, crushing, crushing and the like.

The solid content concentration (also referred to as pulp solid content concentration) of the pulp slurry in the disintegration step is not particularly limited, and can be appropriately selected depending on the purpose and the disintegration device to be used. The pulp solid content concentration is, for example, preferably 2 to 35% by mass, more preferably 3 to 30% by mass, based on the total mass of the pulp slurry. When the pulp solid content concentration is at least the above lower limit value, the productivity is increased, and when it is at least the above upper limit value, better dissociation is possible.
The solid content concentration of the pulp slurry can be adjusted by adding water after adding other chemicals. When the deinking agent composition of the present invention is added from the time of the dissociation step, the solid content concentration of the pulp slurry can be adjusted by adding water after adding other agents and the deinking agent composition. good.
Here, in the present invention, the solid content of the raw material used paper and the pulp solid content of the pulp slurry are the masses of these raw material used paper or the pulp slurry after drying at 80 to 90 ° C. for 18 hours.

The other chemicals are not particularly limited as long as they are chemicals used for recycling used raw paper, and can be appropriately selected depending on the intended purpose. For example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate and the like can be selected. Examples thereof include alkaline agents; bleaching agents such as hydrogen peroxide and sodium hypochlorite; chelating agents such as EDTA and DTPA. Of these, sodium hydroxide and sodium silicate are preferable.
The other drug may be one kind alone or a combination of two or more kinds.

The amount of other chemicals added in the disintegration step is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually 3 parts by mass or less with respect to 100 parts by mass of the solid content (pulp solid content) of the raw material used paper. Is preferable, and an amount of 2 parts by mass or less is more preferable. When the amount of other chemicals added is 3 parts by mass or less, it becomes easy to obtain high-strength recycled pulp.

When the deinking agent composition of the present invention is added from the time of the dissociation step, the amount of the deinking agent composition added is not particularly limited and can be appropriately selected depending on the intended purpose. The amount of the deinking agent composition added in the disintegration step is preferably, for example, an amount in which the total amount of the surfactant is 0.03 to 0.5 parts by mass with respect to 100 parts by mass of the pulp solid content, and 0.1 to 0. An amount of 0.3 parts by mass is more preferable. If the amount of the deinking agent composition added is not less than the above lower limit, the deinking effect can be further improved. When the amount of the deinking agent composition added is not more than the above upper limit, the amount of foaming can be suppressed.

The deinking agent composition may be added to the slurry in a diluted state with water for ease of handling. When diluted with water, it is preferable to add 5 parts by mass or more of water to 100 parts by mass of the deinking agent composition.
Further, the deinking agent composition and another agent may be mixed in advance and added to the raw material used paper in the state of the mixture.

The pH of the pulp slurry in the disintegration step is not particularly limited and may be appropriately selected depending on the intended purpose, but pH 7 to 13 is preferable, and pH 8 to 12.5 is more preferable. When the pH of the pulp slurry is at least the above lower limit value, it becomes easy to dissociate the raw waste paper into fibrous pulp, and when the pH is at least the above upper limit value, it becomes easy to obtain high-strength recycled pulp.

The temperature of the disintegration step (dissolution temperature) is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually preferably 10 ° C to 100 ° C, more preferably 20 ° C to 80 ° C. If the disintegration temperature is 10 ° C. or higher, the raw material waste paper can be easily dissociated into fibrous pulp, and if it is 100 ° C. or lower, high-strength recycled pulp can be easily obtained.

The time for performing the disintegration step (dissolution time) is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually preferably 5 to 60 minutes, more preferably 8 to 50 minutes. If the disintegration time is 5 minutes or more, the raw recycled paper can be easily dissociated into fibrous pulp, and if it is 60 minutes or less, high-strength recycled pulp can be easily obtained.

Various devices can be used in the disintegration step. Examples of the apparatus used in the disintegration step include low-concentration pulper, high-concentration pulper, hot disperser, kneader, mica, fiber flow and the like.

<Floatation process>
The flotation step is a step of flotating the pulp slurry obtained in the decoupling step in the presence of the deinking agent composition to separate the pulp and the ink. At this time, the ink in the pulp slurry is collected together with the foam (floss), so that the recycled pulp from which the ink has been peeled off can be obtained.
The flotation step is preferably performed while blowing air.

The solid content concentration (pulp solid content concentration) of the pulp slurry processed in the flotation step is not particularly limited and can be appropriately selected depending on the intended purpose. It is preferably 0.5 to 3% by mass, more preferably 0.7 to 2.5% by mass, based on the total mass of the pulp slurry in the flotation step. If the pulp solid content concentration is at least the above lower limit value, the foaming amount does not become too large, and if it is at least the above upper limit value, the foaming amount is unlikely to be insufficient.
The pulp solid content concentration can be adjusted by adding water to the pulp slurry.

Further, the concentration of the deinking agent composition in the pulp slurry treated in the flotation step is not particularly limited and can be appropriately selected depending on the intended purpose. The concentration of the deinking agent composition in the flotation step is 0.03 to 0.5 parts by mass for the components (A) to (C) with respect to 100 parts by mass of the solid content (pulp solid content) of the pulp slurry. The amount is preferable, and an amount of 0.1 to 0.3 parts by mass is more preferable. When the concentration of the deinking agent composition is at least the above lower limit value, the deinking effect can be further improved, and when it is at least the above upper limit value, the foaming amount can be suppressed.
When the deinking agent composition is added from the time of the flotation step, or when it is added in the decoupling step and further added in the flotation step, the deinking agent composition in the pulp slurry treated in the flotation step. It is preferable to adjust the amount of the deinking agent composition added so that the concentration of the substance is within the above range.

The pH of the pulp slurry in the flotation step is not particularly limited and can be appropriately selected depending on the intended purpose. pH 7 to 12 is preferable, and pH 8 to 11 is more preferable. When the pH of the pulp slurry is at least the above lower limit value, it is possible to suppress the insufficient foaming amount, and when it is at least the above upper limit value, it is possible to suppress the foaming amount from becoming too large.

The temperature of the flotation step (float temperature) is not particularly limited and may be appropriately selected depending on the intended purpose, but is usually preferably 20 ° C to 60 ° C, more preferably 30 ° C to 50 ° C. When the flotation temperature is at least the above lower limit value, it is possible to suppress the shortage of the foaming amount, and when it is at least the above upper limit value, the ink collectability can be well maintained.

The time for performing the flotation process (floatation time) is not particularly limited and can be appropriately selected according to the purpose.

Various devices can be used in the flotation process. Examples of the apparatus used in the flotation process include various floatators such as a BOX type floatator, an ecocell type, an MT floatator, and an OK floatator.
In addition, instead of the flotation step, the ink removal step by the cleaning method may be prepared again.

<Other processes>
The other steps are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dust removing step, a washing step, a dehydration step, and a drying step.

≪Dust removal process≫
The dust removing step is a step of removing foreign substances such as dust from the pulp slurry obtained in the disintegration step, and is preferably performed before the flotation step.
The method for removing foreign matter from the pulp slurry is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method using a sieve. The mesh size of the sieve is not particularly limited as long as it does not allow foreign matter to pass through and allows the pulp slurry to pass through, and can be appropriately selected depending on the intended purpose.

≪Washing process≫
The washing step is a step of washing the recycled pulp obtained in the flotation step.
The method for washing the regenerated pulp is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the regenerated pulp is filtered with a filter cloth or the like, and water is added to the regenerated pulp remaining on the filter cloth for further filtration. The method and the like can be mentioned.
The cleaning step may be performed a plurality of times.

≪Dehydration process≫
The dehydration step is a step of removing water from the slurry containing the regenerated pulp obtained in the flotation step.
The method for removing water from the slurry containing the regenerated pulp is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method for filtering, a method using a known pressure dehydrator (for example, a screw press, etc.) And so on.

≪Drying process≫
The drying step is a step of drying the recycled pulp obtained in the flotation step.
The method for drying the regenerated pulp is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of natural drying and a method of drying with a known dryer.

(Action effect)
Since the deinking agent composition of the present invention described above contains the above-mentioned components (A) to (C) in a specific ratio, it exhibits an excellent deinking effect regardless of the type of ink. In addition, the deinking agent composition of the present invention can satisfactorily remove foreign substances and increase the yield of pulp by further containing the component (C) in a specific ratio.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following description.
The blending amount of each component shown in the table is a pure content conversion value.

(Raw materials used)
<Ingredient (A)>
-A-1: C ₁₈ H _37- O- (PO) ₂ -[(EO) ₂₂ / (PO) ₁₄ ] -H is a nonionic surfactant. Synthesized in Production Example 1 below.

<< Production Example 1 >> Synthesis of (A-1) Stearyl alcohol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, propylene oxide (2 mol) was ^{added and aged at 125 ° C. and 3.0 kg / cm 2} or less to obtain a PO adduct.
Subsequently, ethylene oxide (22 mol) and propylene oxide (14 mol) were ^{added and aged at 160 ° C. at 3.0 kg / cm 2} or less to obtain a PO-EO / PO adduct. After aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (A-1). In addition, _{EO and PO in (EO 22} / PO ₁₄ ) are random polymerization.

_{· A-2: C 18 H} 37 -O- (PO) 6 - (EO) 28 - (PO) nonionic surface active agents represented by 20 -H. Synthesized in Production Example 2 below.

<< Production Example 2 >> Synthesis of (A-2) Stearyl alcohol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, propylene oxide (6 mol) was ^{added and aged at 125 ° C. and 3.0 kg / cm 2} or less to obtain a PO adduct.
Subsequently, ethylene oxide (28 mol) was ^{added and aged at 160 ° C. at 3.0 kg / cm 2} or less to obtain a PO-EO adduct. Further, propylene oxide (20 mol) was ^{added at 125 ° C. and 3.0 kg / cm 2} or less, and after aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (A-2). Note that EO and PO in (PO) ₆ − (EO) ₂₈ − (PO) ₂₀ are block polymerizations, respectively.

-A-3: A nonionic surfactant represented by _{C 18} H _37- O- (PO) ₆ -[(EO) ₄₀ / (PO) ₅ ]-(PO) _17-H. Synthesized in Production Example 3 below.

<< Production Example 3 >> Synthesis of (A-3) Stearyl alcohol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, propylene oxide (6 mol) was ^{added and aged at 125 ° C. and 3.0 kg / cm 2} or less to obtain a PO adduct.
Subsequently, ethylene oxide (40 mol) and propylene oxide (5 mol) were ^{added and aged at 160 ° C. at 3.0 kg / cm 2} or less to obtain a PO-EO / PO adduct. Further, propylene oxide (17 mol) was ^{added at 125 ° C. and 3.0 kg / cm 2} or less, and after aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (A-3). In addition, EO and PO in [(EO) ₄₀ / (PO) ₅ ] are random polymerization.

<Ingredient (B)>
B-1: C ₁₀ H _21- O- (EO) Nonionic surfactant represented by _8-H. Neugen XL-80 (trade name), manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.
B-2: C ₁₀ H _21- O- (EO) A nonionic surfactant represented by _14-H. Neugen XL-140 (trade name), manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.
B-3: Nonion surfactant represented by _{C 10} H _21- O- (EO) _18-H. Neugen XL-180 (trade name), manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

<Ingredient (C)>
-C-1: Oleic acid. Made by Junsei Chemical Co., Ltd.
-C-2: Stearic acid. Made by Junsei Chemical Co., Ltd.
C-3: A mixture of TFA-80M (4% by mass of palmitin, 10% by mass of stearic acid, 39% by mass of oleic acid, 25% by mass of linoleic acid, 5% by mass of linolenic acid, and 17% by mass of other carbon atoms 16 and 18). Fatty acid, iodine value 101). Made by Tsukino Food Industry Co., Ltd.

<Component (H)> Nonionic surfactant other than components (A) to (B) H-1: C ₄ H _9- O- (EO) Nonionic surfactant represented by _10-H. Synthesized in Comparative Production Example 1 below.

<< Comparative Production Example 1 >> Synthesis of (H-1) n-butanol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, ethylene oxide (10 mol) was ^{added and aged at 160 ° C. and 3.0 kg / cm 2} or less to obtain an EO adduct. After aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (H-1).

H-2: C ₈ H _17- O- (EO) Nonion surfactant represented by _4-H. Synthesized in Comparative Production Example 2 below.

<< Comparative Production Example 2 >> Synthesis of (H-2) 2-Ethylhexanol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, ethylene oxide (4 mol) was ^{added and aged at 160 ° C. at 3.0 kg / cm 2} or less to obtain an EO adduct. After aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (H-2).

H-3: C ₈ H _17- O- (EO) Nonionic surfactant represented by _24-H. Synthesized in Comparative Production Example 3 below.

<< Comparative Production Example 3 >> Synthesis of (H-3) 2-Ethylhexanol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, ethylene oxide (24 mol) was ^{added and aged at 160 ° C. at 3.0 kg / cm 2} or less to obtain an EO adduct. After aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (H-3).

H-4: C ₁₈ H _37- O- (EO) Nonionic surfactant represented by _10-H. Synthesized in Comparative Production Example 4 below.

<< Comparative Production Example 4 >> Synthesis of (H-4) Stearyl alcohol (1 mol) and KOH as a catalyst were charged in an autoclave, subjected to nitrogen substitution, and then dehydrated under reduced pressure. Subsequently, ethylene oxide (10 mol) was ^{added and aged at 160 ° C. and 3.0 kg / cm 2} or less to obtain an EO adduct. After aging, the mixture was cooled and adjusted to pH 6 to 8 with acetic acid to obtain the desired compound (H-4).

<Raw raw paper>
As the target of the deinking treatment, used printed paper having the composition shown in Table 1 was used.

(Evaluation method)
<Pulp yield>
From the floss mass (g) and floss solid content (mass%) obtained in the flotation step, the pulp yield was calculated by the following (1). The calculated pulp yield was classified into the following evaluation criteria.
Pulp yield (mass%) = {(40- [floss mass (g) x floss solid content (mass%) ÷ 100) / 40} x 100 ... (1)
"40" in the formula (1) is the pulp solid content mass obtained by the following formula (2).
Pulp solid content weight (40 g) = processed pulp slurry mass (4000 g) x pulp solid content concentration (1% by mass) ... (2)

≪Evaluation criteria≫
◎ (Very preferable level): Pulp yield of 80% by mass or more.
○ (Preferable level): Pulp yield of 79% by mass or more and less than 80% by mass.
Δ (level requiring improvement): Pulp yield 78% by mass or more and less than 79% by mass.
× (level that is not economically suitable): Pulp yield less than 78% by mass.

<Whiteness>
The whiteness (ISO,%) of the obtained test paper was measured with a color difference meter (spectral color / whiteness meter PF-10 manufactured by Nippon Denshoku Kogyo Co., Ltd.). The whiteness measurement results were classified into the following evaluation criteria.

≪Evaluation criteria≫
◎ (Excellent quality): Whiteness of 50% or more.
○ (usable level): Whiteness 49% or more and less than 50%.
△ (The target quality has not been reached): Whiteness is 48% or more and less than 49%.
× (level unsuitable for use): Whiteness less than 48%.

<Dirt rate>
Using a today's matter measuring instrument (Spec * Scan2000 / 2001, manufactured by Nomura Shoji Co., Ltd.), the dirt area ratio (ppm) ^{of 0.01 mm 2 or more of the test paper was measured.} The obtained dirt area ratio was classified into the following evaluation criteria.

≪Evaluation criteria≫
◎ (Excellent quality): Dirt area ratio 300ppm or less.
○ (usable level): Dirt area ratio of more than 300 ppm and 350 ppm or less.
△ (The target quality has not been reached): Dirt area ratio is more than 350ppm and 400ppm or less.
× (level unsuitable for use): Dirt area ratio over 400 ppm.

(Examples 1-9, Comparative Examples 1-14)
Each component was weighed according to the composition of the deinking agent composition shown in Tables 2 to 4 to obtain the deinking agent composition of each example.

After cutting the raw material waste paper into 1 x 3 cm, put it in a low concentration pulper (manufactured by Kumagai Riki Kogyo Co., Ltd., low concentration pulper lab machine), and 0.5 parts by mass of sodium hydroxide for every 100 parts by mass of the raw material used paper. 0.15 parts by mass of the deinking agent composition was added. Subsequently, warm water was added so that the pulp concentration was 5% by mass, and pulper treatment (crushing of the raw material used paper) was performed at 40 ° C. for 10 minutes (dissolution step).

The obtained pulp slurry was diluted with warm water to obtain a pulp slurry (4000 g) having a pulp concentration of 1% by mass, and the pulp slurry was floated at 40 ° C. for 5 minutes. The amount of air blown was set so that G / L was 6 (floatation step). In this way, the raw material used paper was deinked in the order of the disintegration process and the flotation process.
The total mass of the floss discharged by the flotation treatment was measured, and about 150 g of the floss was precisely weighed in an evaporating dish and dried at 80 to 90 ° C. for 18 hours to determine the dry solid content (% by mass) of the floss. The pulp yield was determined from the obtained floss mass (g) and floss solid content (mass%).

500 g of the pulp slurry after the flotation step was diluted with water to 1000 g, and paper was made using a TAPPI sheet machine. The pulp sheet on the filter paper was sandwiched between the SUS plate and the filter paper, pressed for 5 minutes, and then dried at room temperature to obtain a test paper. The whiteness and the dirt area ratio of the obtained test paper were measured, and the results are shown in Tables 2-4.

As shown in Tables 2 to 4, in Examples 1 to 9, all of the pulp yield, the whiteness and the dirt area ratio were "◎" or "○". Above all, the dirt area ratio of Examples 4 to 9 containing the component (C) was even smaller than that of Examples 1 to 3.
In Comparative Examples 1 to 6 lacking the component (B), either the whiteness or the dirt area ratio was "Δ" or "x".
In Comparative Examples 7 to 10 in which the A / B ratio or the (A + B) / C ratio was outside the range of the present invention, either the whiteness or the dirt area ratio was “Δ” or “×”.
In Comparative Examples 11 to 14 containing the component (H) instead of the component (B), either the whiteness or the dirt area ratio was "Δ" or "x".
From the above results, it was confirmed that the deinking effect can be enhanced by applying the present invention.

Claims (4)

Component (A): a nonionic surfactant represented by the following formula (a) and component (B): a nonionic surfactant represented by the following formula (b), and component (C): It may contain a fatty acid having 12 to 24 carbon atoms or a salt thereof.
The mass ratio represented by the component (A) / the component (B) is 60/40 to 99/1.
A deinking agent composition having a mass ratio represented by (the component (A) + the component (B)) / the component (C) of 40/60 to 100/0.
R ¹ −O− [(EO) _m / (PO) _n ] −H ・ ・ ・ (a)
In the formula (a), R ¹ is an alkyl group or an alkenyl group having 14 to 24 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and m represents the average number of repetitions of EO. It is a number of ~ 80, and n is a number of 4 to 60 representing the average number of repetitions of PO. (EO) _m / (PO) _n means that there is no limitation on the addition form of EO and PO. )
R ^2- O- (EO) _x- H ... (b)
(B) In the formula (b), R ² is an alkyl group having 10 to 14 carbon atoms. EO represents an ethyleneoxy group. X is a number of 8 to 20 representing the average number of repetitions of EO.) The component (A) is selected from the group consisting of a component (A1): a nonionic surfactant represented by the following formula (a1) and a component (A2): a nonionic surfactant represented by the following formula (a2). The deinking agent composition according to claim 1, which is at least one kind.
R ^11- O- (PO) _t- (EO) _u- (PO) _v- H ... (a1)
In the formula (a1), R ¹¹ is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and t represents the average number of repetitions of PO 1. It is a number of 10 to 10, u is a number of 10 to 40 representing the average number of repetitions of EO, and v is a number of 3 to 40 representing the average number of repetitions of PO.)
R ^12- O- (PO) _p -[(EO) _q / (PO) _r ]-(PO) _s- H ... (a2)
In the formula (a2), R ¹² is an alkyl group or an alkenyl group having 16 to 22 carbon atoms. EO represents an ethyleneoxy group, PO represents a propyleneoxy group, and p represents the average number of repetitions of PO 1. It is a number of 10 to 10, q is a number of 31 to 60 representing the average number of repetitions of EO, r is a number of 1 to 15 representing the average number of repetitions of PO, and s represents the average number of repetitions of PO. It is a number of 3 to 30. (EO) _q / (PO) _r means that there is no limitation on the addition form of EO and PO.) It contains the component (C) and contains
The deinking agent composition according to claim 1 or 2, wherein the mass ratio represented by (the component (A) + the component (B)) / the component (C) is 45/55 to 95/5. In a method for producing recycled pulp, which is obtained by peeling ink from raw material waste paper and removing the peeled ink to obtain recycled pulp.
A method for producing recycled pulp, which comprises a step of performing a deinking treatment on raw recycled paper in the presence of the deinking agent composition according to any one of claims 1 to 3.