JP4322800B2 - Deinking agent - Google Patents

Description

  The present invention relates to a deinking agent used when recycling recycled newspaper, magazine waste, OA wastepaper, colored wastepaper, and the like to obtain recycled paper, and a deinking method using the same.

  The recycling of the used paper is performed by removing / removing ink from the used paper to obtain recycled pulp and producing recycled paper by deinking treatment. The deinking agent used in this process has conventionally enhanced the ability to peel ink with the advance of printing technology. Specific examples include deinking agents that use fatty acids, fatty acid alkylene oxide adducts, higher alcohol alkylene oxide adducts, and the like. In addition, a technique in which a higher alcohol alkylene oxide and a fatty acid are used in combination to improve the removal efficiency of the peeled ink has been reported.

  However, in recent years, the sorting of recovered recovered paper has progressed, the distribution route of recovered recovered paper has been established and the time from recovery to deinking has been shortened, the development of deinking equipment has advanced, and strong mechanical power has been applied. As a result of the enhanced ink peeling, increased leaflets that are advantageous for ink peeling, and increased use of coated paper such as colored waste paper, ink peeling is relatively easy, and ink collection (rather than ink peeling) ( The ink separated from the used paper is adsorbed and collected on the surface of the bubbles and floats together with the bubbles, thereby preventing the recombination of the ink into the pulp and the ability to completely separate the ink and the pulp). .

  Under these circumstances, higher alcohol alkylene oxides, which are considered to have strong ink removability, have sufficient ink dispersibility, although ink releasability is sufficient with respect to used paper. The problem of end up happening. In order to improve the ink collecting property, a fatty acid is also used in combination. However, it is not sufficient, and agglomeration of the sticky material is caused in part.

  On the other hand, there is an option to use a deinking agent with weak ink dispersibility, such as the fatty acid alkylene oxide adducts used in the past, but the ink collecting property is weak and the ink releasability is insufficient and a high addition rate is required. Is done. In view of the above situation, it is desired to provide a deinking agent having a good balance between ink releasability and ink collecting property.

  Patent Document 1 discloses an amide compound to which ethylene oxide is added, a deinking agent for used paper recycling containing an anionic surfactant and a higher fatty acid (salt), and the amide compound is an ink collecting property of higher fatty acid. It acts to increase the foamability of the anionic surfactant without inhibiting the above.

Patent Document 2 discloses a compound obtained by adding an alkylene oxide to an alcohol, an amide, or a fatty acid as a nonionic surfactant that dissolves the fatty acid mixture. As a most preferable embodiment, ethylene oxide is added to a higher alcohol, Nonionic surfactants with added propylene oxide are disclosed.
JP-A-61-89394 JP-A-8-120581

  In the inventions disclosed in Patent Documents 1 and 2, it is not possible to provide a deinking agent having a good balance between ink releasability and ink collecting property.

  An object of the present invention is to provide a deinking agent having good and balanced ink releasability and ink collecting property, and a deinking method using the same.

As a means for solving the problems, the present invention
A deinking agent comprising a compound obtained by adding an alkylene oxide to an amide compound having a hydrogen atom at the amide nitrogen;
The alkylene oxide contains xmoles of ethylene oxide units on average, ymoles of propylene oxide units on average, and zmoles of butylene oxide units on average, and x, y and z are the following (I) to (IV) And a deinking method using the deinking agent.

2 ≦ x ≦ 100 (I)
2 ≦ y ≦ 100 (II)
0 ≦ z ≦ 100 (III)
0.1 ≦ x / (y + z) ≦ 10 (IV)

  The deinking agent of the present invention has both high ink releasability and ink collecting properties, and can produce high-quality deinked pulp.

<Deinking agent>
The amide compound having a hydrogen atom in the amide nitrogen used in the present invention is preferably selected from amide compounds represented by the general formulas (1) and (2).

[Wherein, R ¹ represents an alkyl group having 6 to 24 carbon atoms and an alkenyl group having 6 to 24 carbon atoms, and R ² represents hydrogen, an alkyl group having 1 to 24 carbon atoms, and ^{2 to} 24 carbon atoms. Represents an alkenyl group selected from

R ¹ is selected from linear or branched alkyl groups having 6 to 24 carbon atoms and linear or branched alkenyl groups having 6 to 24 carbon atoms, and linear or branched carbon atoms having 8 to 8 carbon atoms. Those selected from 22 alkyl groups and linear or branched alkenyl groups having 8 to 22 carbon atoms are more preferred.

R ² is selected from hydrogen, a linear or branched alkyl group having 1 to 24 carbon atoms, and a linear or branched alkenyl group having 2 to 24 carbon atoms. Those selected from an alkyl group having 8 to 22 carbon atoms and a linear or branched alkenyl group having 8 to 22 carbon atoms are more preferable.

[Wherein R ³ represents an alkyl group having 6 to 24 carbon atoms and an alkenyl group having 6 to 24 carbon atoms, and R ⁴ represents hydrogen, an alkyl group having 1 to 24 carbon atoms, and 2 to 24 carbon atoms. And n represents a number of 2 to 6].

R ³ is selected from linear or branched alkyl groups having 6 to 24 carbon atoms and linear or branched alkenyl groups having 6 to 24 carbon atoms, and linear or branched carbon atoms having 8 to 8 carbon atoms. Those selected from 22 alkyl groups and linear or branched alkenyl groups having 8 to 22 carbon atoms are more preferred. n is a number from 2 to 6, and 2 is particularly preferable.

R ⁴ is selected from hydrogen, a linear or branched alkyl group having 1 to 24 carbon atoms, and a linear or branched alkenyl group having 2 to 24 carbon atoms. Those selected from an alkyl group having 8 to 22 carbon atoms and a linear or branched alkenyl group having 8 to 22 carbon atoms are more preferable.

  Examples of the amide compound of the general formula (1) or (2) include alkylamides, alkenylamides, N-alkylalkylamides, dialkylethylenebisamides, dialkyleneethylenebisamides, and the like.

  Specifically, hexylamide, octylamide (caprylamide), nonaamide, decamide, undecamide, dodecamide (laurylamide), tetradecamide (myristylamide), hexadecamide (palmethylamide), octadecamide (stearylamide) ), Isostearylamide, oleylamide, eicosamide, docosylamide, 2-ethylhexylamide, N-methylhexylamide, N-methyloctylamide, N-methylnonamide, octylstearylethylenebisamide, dilaurylethylenebisamide, dimyristylethylenebisamide , Dipalmethylethylenebisamide, distearylethylenebisamide, diisostearylethylenebisamide, dioleylethylenebisamide, and the like.

  The alkylene oxide used in the present invention contains ethylene oxide (EO) units on average x moles, propylene oxide (PO) units on average y moles, butylene oxide (BO) units on average z moles, x, y and z satisfy the following relationships (I) to (IV), and preferably satisfy the following relationships (I) to (V). Random addition is preferable as the addition form when adding alkylene oxide.

2 ≦ x ≦ 100 (I)
2 ≦ y ≦ 100 (II)
0 ≦ z ≦ 100 (III)
0.1 ≦ x / (y + z) ≦ 10 (IV)
4 ≦ x + y + z ≦ 200 (V)
The average added mole number (x) of ethylene oxide (I) is preferably 2 to 100 mol, more preferably 5 to 80 mol, and particularly preferably 10 to 80 mol.

  The average added mole number (y) of propylene oxide (II) is preferably 2 to 100 mol, more preferably 5 to 80 mol, and particularly preferably 10 to 60 mol.

  The average added mole number (z) of butylene oxide (III) is preferably 100 mol or less, more preferably 0 to 50 mol, particularly preferably 0 to 20 mol.

  X / (y + z) of (IV) is 0.1 to 10, more preferably 0.3 to 3.

  (X + y + z) of (V) is preferably 4 to 200 mol, more preferably 10 to 160 mol.

  Here, the average added mole number of alkylene oxide means the average added mole number per molecule. For example, in the case of an amide compound having two hydrogen atoms in the amide nitrogen, it is the total of two alkylene oxide chains. .

  The deinking agent of the present invention can be produced by applying a polymerization addition reaction of alkylene oxide, which is generally performed conventionally. For example, it can be produced by applying a method in which an alkaline compound is added as a catalyst to an amide compound having a hydrogen atom in amide nitrogen in a nitrogen atmosphere, and a predetermined amount of alkylene oxide having a predetermined composition is subjected to addition polymerization.

  The deinking agent of the present invention may be, for example, one or more selected from deinking agents using the amide compound of the general formula (1), and deinking using the amide compound of the general formula (2). One kind or two or more kinds selected from inks may be used, or a mixture thereof.

  A mixture of a deinking agent [deinking agent (1)] using the amide compound of the general formula (1) and a deinking agent [deinking agent (2)] using the amide compound of the general formula (2) Although the ratio is not particularly limited, the mass ratio of the deinking agent (1) / deinking agent (2) is preferably 1/9 to 9/1, more preferably 1/3 to 3/1.

<Deinking method>
In the deinking method using the deinking agent of the present invention, it is preferable to use 0.02 to 2 parts by weight of the deinking agent, more preferably 0 to 100 parts by weight (absolutely dry weight) of the waste paper raw material to be processed. 0.05 to 1.0 part by weight, particularly preferably 0.1 to 0.6 part by weight.

  In the deinking method of the present invention, the deinking agent of the present invention and a known deinking agent can be mixed and used. Known deinking agents include fatty acids and fatty acid salts, fatty acid-alkylene oxide adducts, higher alcohol-alkylene oxide adducts, alkylamine-alkylene oxide adducts, polyoxyalkyl ether sulfates, alkylbenzene sulfonates, and the like. However, it is not limited to these.

  In the deinking method of the present invention, a deinking agent and an inorganic chemical such as caustic soda, sodium silicate, hydrogen peroxide, etc. can be used in combination.

  In the deinking method of the present invention, the deinking agent can be added and used in a batch or divided in the ink peeling step, the ink removing step, and the washing step. Specifically, it can be added before or during the work of the ink peeling process such as a pulper, kneader, chemical mixer, etc., the ink removing process such as a flotator, and the cleaning process such as thickener, washer and extract. In particular, the deinking agent of the present invention is preferably subjected to a flotation treatment after the addition, and is desirably added before the flotation step.

  The deinking mechanism of the deinking agent of the present invention has not been fully elucidated, but is thought to be as follows.

  It is presumed that the ink releasability is due to the surface activity as a nonionic surfactant. Conventionally, higher alcohol-based nonionic surfactants are known as deinking agents with good ink release properties, but the alkylamide group of the alkyl group moiety as a hydrophobic group in the deinking agent of the present invention is higher alcohol. Therefore, it is considered that excellent ink releasability is exhibited.

  In terms of ink trapping properties, alkyl groups of higher alcohol nonionic surfactants and fatty acid nonionic surfactants are only hydrophobic, whereas alkylamide groups have polarized nitrogen and carbonyl groups. Because of its polarity, the interaction with the ink having negative charge on the surface in the deinking system becomes stronger, and the aggregation of the ink is promoted or the adsorption of the ink to the bubbles is promoted. , More ink can be adsorbed and collected on the bubble surface and floated along with the bubbles. As a result, it is presumed that the separation efficiency between the pulp and the ink is improved, and the ability to completely separate the ink and the pulp separated from the used paper by preventing recombination is exhibited.

  Examples of the waste paper to which the deinking agent and the deinking method of the present invention are applied include newspaper waste paper, flyer waste paper, magazine waste paper, colored waste paper, OA waste paper, and mixed waste paper thereof, but are not particularly limited. Absent.

  The deinking agent and the deinking method of the present invention are used when producing recycled paper using these waste papers as raw materials, and more specifically, in the deinking process by the flotation method, the washing method, and its eclectic method. Used, and particularly exhibits good deinking performance in the flotation method.

Examples and Comparative Examples [Deinking Method]
Caustic soda 1.5 parts by weight, No. 3 sodium silicate 1.5 parts by weight, hydrogen peroxide 0. 5 parts by weight, the deinking agent shown in Table 1, and 1900 parts by weight of water were placed in a disaggregator and disaggregated for 10 minutes at 3000 rpm.

  Next, it concentrated with a 150 mesh stainless steel wire until the pulp concentration became 25%, and bleaching was performed at 60 ° C. for 60 minutes. Then, 40 degreeC water was added so that it might become a pulp density | concentration 1%, and the pulp was disperse | distributed well and the pulp slurry was obtained. Using this pulp slurry, flotation was performed for 10 minutes at an air supply rate of 1.5 L / min per 1 L of pulp slurry using a lab flotator, and ink was collected and removed out of the processing system.

[Whiteness evaluation]
A handsheet was prepared according to JIS P8209-1994 so that the pulp slurry after the flotation obtained by the deinking treatment had a basis weight of 150 g / cm ² with a 150 mesh wire. This sheet was measured according to JIS 8123-1961 using a whiteness meter PF-10 manufactured by Nippon Denshoku. In addition, that whiteness is excellent means that both ink collection property and ink peelability are good.

[Evaluation of ink peelability]
A fixed amount of the pulp slurry after flotation obtained by deinking treatment was taken, diluted with water 15 times the volume of the slurry, and then concentrated to a pulp concentration of 13% with 150 mesh wire. Furthermore, after diluting with 200 times water, the operation of concentrating with a 150 mesh wire to a pulp concentration of 13% was performed 4 times to obtain a pulp slurry from which free ink was completely removed.

A handsheet was prepared according to JIS P8209-1994 so that the basis weight was 150 g / cm ² with a 150 mesh wire. This sheet was measured at a magnification of 20 times using Luzex F manufactured by Nireco Corp., and the amount of unpeeled ink was calculated according to the following formula.

Unpeeled ink area ratio (%) = (S / F) × 100
S: 100 Ink area measured during field F: 100 viewing total area 15000 ² (1 viewing area 150 mm ²⁾ of

From the results of Table 2, it is clear that the examples have good ink collecting properties in flotation and are compatible with ink peelability. In addition, the difference of 0.5 point of whiteness and the difference of the unpeeled ink area ratio of 0.05 are such that the superiority difference can be sufficiently confirmed visually.

Claims (5)

A deinking agent comprising a compound obtained by adding an alkylene oxide to an amide compound represented by the following general formula (2) :
The alkylene oxide contains xmoles of ethylene oxide units on average, ymoles of propylene oxide units on average, and zmoles of butylene oxide units on average, and x, y and z are the following (I) to (IV) Deinking agent that satisfies the relationship.
2 ≦ x ≦ 100 (I)
2 ≦ y ≦ 100 (II)
0 ≦ z ≦ 100 (III)
0.1 ≦ x / (y + z) ≦ 10 (IV)

[Wherein R ³ represents an alkyl group having 6 to 24 carbon atoms and an alkenyl group having 6 to 24 carbon atoms, and R ⁴ represents hydrogen, an alkyl group having 1 to 24 carbon atoms, and 2 to 24 carbon atoms. Represents an alkenyl group, and n represents a number of 2 to 6. ]   R ^Three Is selected from linear or branched alkyl groups having 8 to 22 carbon atoms and linear or branched alkenyl groups having 8 to 22 carbon atoms, and n is 2. Ink.   R ^Four The deinking according to claim 1 or 2, wherein is selected from hydrogen, a linear or branched alkyl group having 8 to 22 carbon atoms, and a linear or branched chain alkyl group having 8 to 22 carbon atoms. Agent. Relative to 100 parts by weight of waste paper raw material deinking agent according to any one of claims 1 to 3, 0. Deinking method using 02 to 2 parts by weight. The deinking method according to claim 4, wherein a flotation treatment is performed after addition of the deinking agent.