JP4794346B2 - Deinking method and deinking agent - Google Patents

Description

The present invention relates to a deinking method and a deinking agent that effectively promotes deinking in the process of producing deinked pulp from used paper raw materials, and produces high-quality deinked pulp from used paper raw materials including so-called hard-to-deink wastepaper. Is.

  The use of deinked pulp (hereinafter referred to as DIP) produced by deinking waste paper raw materials as a papermaking raw material has been practiced for a long time. In recent years, the reuse of waste paper has become more important from the viewpoint of resource protection, and the use of low-grade waste paper, which has been low so far, such as magazine waste paper and office waste paper, has progressed along with further expansion of the waste paper usage rate. Yes. In addition, newspaper waste paper, which is the mainstream of raw paper, has been shifting from acidic papermaking to neutral papermaking, and the properties of the raw paper itself are changing greatly. On the other hand, in terms of printing ink, printing ink contained in waste paper that is reused by shifting to eco-ink such as soybean oil ink and UV ink is also changing. Further, in the manufacturing process of DIP, the environment surrounding DIP is changing day by day, such as an increase in the circulation rate of water used in the deinking process.

Soybean oil ink has a lower dry film strength than the ink using conventional linseed oil, and the ink can be easily peeled off in the deinking process, but the free ink is easily refined. On the other hand, UV ink and toner ink are known to have higher strength after printing than inks using linseed oil, etc. When printed matter using these inks is mixed in waste paper, large ink particles in DIP Remains and causes damage. In such a case, measures such as mechanically crushing the ink particles to make them finer are taken, but the amount of fine free ink particles increases because the ink content using linseed oil mixed with these hard inks is also refined To do. Currently, in the flotation method, which is the mainstream in the manufacturing process of DIP, it is known that the ink removability in the flowator that mainly performs deinking decreases with the increase in fine ink, An increase in ink particles leads to a decrease in the quality of DIP.
In addition, fine free ink that could not be removed by the floatator can be removed by the washing process, but since the ink that has flowed into the working water returns to the process again due to the recent increase in the water circulation rate, Fine ink accumulates in the water, causing a drop in DIP quality.
Furthermore, when the quality of DIP deteriorates, the whiteness is improved by reductive bleaching using hydrogen peroxide to maintain the quality. However, the increase in fine free ink in DIP is such as hydrogen peroxide as a bleaching agent. This not only increases the production cost by increasing the amount of sucrose, but also increases the number of microorganisms such as reducing bacteria, which increases the trouble caused by slime.
In recent years, there has been a shift to neutral paper making, which is the mainstream of deinking raw materials, but compared to acidic paper used for neutral paper, neutral paper used is affected by the chemicals used, etc. Ink releasability tends to decrease, and the amount of unpeeled ink called whisker increases with conventional mechanical stress. In order to reduce the unpeeled ink, it is necessary to increase the mechanical stress, but in the case of the acid-made newspaper wastepaper mixed in the wastepaper raw material, the ink peelability becomes excessive and the free ink has been made finer. DIP quality deteriorates because fine ink accumulates.
In order to improve the DIP quality deterioration due to fine ink, it is necessary to adjust the particle size so that the ink can be easily removed by the flotation method by suppressing the ink fineness or re-aggregating the fine ink.

  Thus, in the situation where so-called hard-to-deink wastepaper is increasing in wastepaper raw materials, conventional deinking agents (see Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4) Ink removability with a rotator was not sufficient, and it was difficult to control the quality of DIP due to fluctuations due to seasonal factors and fluctuations in the waste paper itself.

On the other hand, methods for using terpene alcohols or terpene hydrocarbons at the time of recycling used paper have been proposed. For example, in Patent Documents 5 and 6, terpene-based pine oil is used for adjusting a carrier that adsorbs ink released in the deinking process. In Patent Document 7, d-limonene, which is a terpene hydrocarbon, is used as an organic solvent for dissolving a mixture of SB and SIS rubber used as a main component of a deinking agent. In these patents, terpene-based substances are only used for the purpose of adjusting the main components of other deinking agents, and it cannot be said that terpene-based compounds are used for the purpose of utilizing deinking properties.
Further, in Patent Document 8, it is said that the melting point of soaps can be lowered and handled easily by combining soaps and terpene alcohols by partial saponification of fatty acids and fats and oils. However, deinking agents using a combination of soaps and terpene alcohols cannot be said to have sufficient deinking properties in recent years when low-grade waste paper increases.
Patent Document 9 describes that a deinking agent comprising a mixture of pine oil, soybean oil, a short carbon chain monocarboxylic acid and a glycol ether solvent is useful as a deinking agent for water-soluble flexographic ink prints. In general, water-soluble flexographic ink prints are easily peeled off, but sufficient ink peelability cannot be obtained on recent printed paper. In addition, glycol ether solvents cause the free ink to become finer and the flotation property is lowered, so that it cannot be said that it has a sufficient deinking property as a deinking agent in the flotation method.
Japanese Patent Laid-Open No. 55-51891 JP-A-55-51892 JP-A-8-284087 JP 2002-327384 A Japanese Patent No. 56-50037 U.S. Pat. No. 4,013,505 International Publication No. 98/55683 Pamphlet JP 58-215500 A European Patent Application No. 446 564

The problem to be solved by the present invention is that a deinking method typified by a flotation method is used in a floatator in order to stably produce high-quality DIP from used paper raw materials including so-called hard-to-deink wastepaper. It is an object of the present invention to provide a deinking method for effectively improving ink removability and a deinking agent for improving ink removability with a flowator.

  The present invention relates to a deinking method characterized by adding a terpene alcohol and a compound having a polyoxyalkylene group in the process in the process of producing a deinked pulp by deinking the ink contained in the waste paper raw material. .

  In another embodiment of the present invention, (a) a terpene alcohol and (b) a compound having a polyoxyalkylene group are contained, and the weight ratio thereof is (a) :( b) = 1: 99 to 99: 1. There are deinking agents characterized by being.

In another embodiment of the present invention, there is provided the deinking agent, wherein the compound (b) having a polyoxyalkylene group is a compound represented by the following general formula (1).
R ¹ —O— (AO) p—H (1)
(Wherein R ¹ represents an alkyl group having 1 to 24 carbon atoms, an alkenyl group, or an aryl group having 6 to 30 carbon atoms, AO represents an oxyalkylene group having 2 to 4 carbon atoms, and p is an integer of 1 to 200) .)

  The terpene alcohols used in the present invention are terpene compounds having a structure of (C5H8) n and are compounds having a hydroxyl group. There are terpene alcohols corresponding to each structure, which are classified into monoterpenes (n = 2), sesquiterpenes (n = 3), diterpenes (n = 4) and the like depending on the difference in carbon number. There are various types of terpene alcohols, but examples include compounds belonging to monoterpene alcohols such as terpineol, geraniol, citronellol, tweenol, linalool, menthol, carveol, borneol, etc. and sesquiterpene alcohols such as atlantol, elemol, There are casinool, catrol, globrol, nerolidol, patchoulol, valeranol, fanesole, redol, pogosterol and the like, and diterpenes include phytol, sclareol, manol, hinokiol and the isomers thereof. Among these, terpene alcohols that are liquid at normal temperature and normal pressure, such as terpineol, are preferable in terms of ease of workability.

  Furthermore, terpene alcohols have structural isomers. For example, terpineol has three types of isomers, α-form, β-form, and γ-form, but a large difference in deinking property due to the difference in structure has not been confirmed. It was. For example, there was no significant difference in deinking properties between terpineol (α-form, β-form, γ-form mixture) and α-terpineol (alpha-form). From this result, it is thought that there is no big difference between the structural isomers of various terpene alcohols. Further, terpene alcohols are generally sold as a mixture of isomers and terpene hydrocarbons, but a higher content of terpene alcohol is more preferable from the viewpoint of performance improvement.

  In the deinking method by the flotation method, when terpene alcohols are added to the deinking step, a significant improvement in deinking properties is confirmed. On the other hand, when comparing the DIP quality of the completely washed pulp from which the ink from which DIP is liberated with fresh water is removed, there is almost no difference in quality from the case where terpene alcohol is not used. The quality of the completely washed pulp is an index of the ink removability of the deinking agent. If the ink removability is excellent, the quality of the completely washed pulp is improved. With regard to terpene alcohol, the effect of improving the ink peelability was not confirmed, but a decrease in the ink peelability was not confirmed. From this result, it is considered that terpene alcohol has improved the collection property and deinking property of fine free ink particles without inhibiting or reducing the ink releasability.

  On the other hand, when a terpene compound having no hydroxyl group in the molecule, such as α-pinene and terpinolene, was added to the deinking step, the deinking property was lowered. On the other hand, the deinking property of the completely washed pulp is almost the same as that when no terpene compound is added. Although the detailed mechanism of this result is unknown, the affinity to water is probably reduced due to the absence of a hydroxyl group, and the terpene compound incorporating the ink is not adsorbed by the bubbles in the flotation, making it more hydrophobic. It is thought that the DIP quality was lowered because it preferentially adsorbed to strong pulp fibers. JP-T-3-504523 discloses a deinking agent comprising a mixture of a high foaming-low emulsifying surfactant and a terpene, and a solvent for the terpene. As the terpene, d-limonene, dipentene, Although terpene hydrocarbons such as α-pinene, β-pinene, turpentine oil, and terpentine are described as effective, the effectiveness of these terpene hydrocarbons as deinking agents has been confirmed by the present inventors' verification. Was not.

  In addition, when a short carbon chain saturated alcohol such as 2-ethylhexanol is added to the deinking process, ink removability at the time of washing after flotation is improved, but ink removability at the time of flotation is reduced. However, the quality of the completed DIP is decreasing. From this result, it is considered that the carbon skeleton of the terpene compound greatly contributes to the improvement of the aggregation property and the deinking property of the free ink.

Examples of the compound having a polyoxyalkylene group used in the present invention include higher alcohol alkylene oxide (hereinafter referred to as AO) adduct, fatty acid AO adduct, fat and oil AO adduct, amine AO adduct, phosphate ester AO adduct, polyvalent There are AO adducts of a mixture (reaction product) of carboxylic acid and alcohol. Here, examples of AO include ethylene oxide (hereinafter referred to as EO), propylene oxide (hereinafter referred to as PO), and butylene oxide (hereinafter referred to as BO). However, in terms of economy and the ability to adjust performance depending on the addition form of AO. It is preferable to use both ethylene oxide and propylene oxide. Moreover, 1-200 mol is preferable, as for the addition mole number of AO, 10-100 mol is more preferable, and 30-50 mol is further more preferable.

Among the compounds having a polyoxyalkylene group, the compound represented by the general formula (1) is particularly preferable in that it has an excellent deinking effect. In the general formula (1), R ¹ is preferably an alkyl group or an alkenyl group having 8 to 22 carbon atoms from the viewpoint of improving the deinking performance. In the deinking of hard-to-deink waste paper such as UV ink, R ¹ Thirty aryl groups are preferred. 10-100 mol is preferable and, as for p, 30-50 mol is more preferable. In addition, the properties of the compound can be changed by changing the addition form of EO or PO. In other words, in the deinking process of each paper manufacturer, the required ink peelability and cohesiveness change depending on the change in machine type and share, and the state of the raw paper, but the addition form of AO in the compound should be adjusted. This makes it possible to deal with various deinking conditions.

  The blending ratio of (a) terpene alcohols and (b) a compound having a polyoxyalkylene group is preferably in the range of (a) :( b) = 1: 99 to 99: 1 by weight ratio, ) :( b) = 10: 90 to 90:10 is more preferable, and (a) :( b) = 30: 70 to 70:30 is more preferable. Even if each component was added without being mixed, or a premixed mixture was added, no particular difference in performance was confirmed, but a premixed mixture is preferred in terms of transportation and storage.

In addition, anionic surfactants such as alkyl ether sulfates and fatty acid soaps can be used for the purpose of adjusting the foaming property and antifoaming property in the flotation as long as the deinking performance is not impaired. However, the use of a fatty acid soap or the like is a combined use for the purpose of adjusting foam suppression properties, and the DIP quality is greatly lowered when a compound having a polyoxyalkylene group is not used together. Furthermore, alkalis such as caustic soda, sodium silicate, sodium carbonate and sodium phosphate, and chelating agents such as EDTA can also be used. In addition, a whitening degree of DIP can be increased by using a bleaching agent such as hydrogen peroxide together.

  A compound having a terpene alcohol and a polyoxyalkylene group can be added in each step such as a waste paper disaggregation step, a bleaching step, and a flotation step. Further, a deinking agent combined with a known deinking agent can be added in the same place.

  The deinking method and the deinking agent according to the present invention show excellent deinking properties not only for newspaper wastepaper but also for deinking so-called hard-to-deink wastepaper such as high-quality wastepaper and OA wastepaper, and the DIP quality is improved. .

Examples of the present invention are shown below, but are not limited thereto.

(Component A terpene alcohol)
Commercially available terpene alcohols shown in Table 1 were used.

(Component B Compound having a polyoxyalkylene group)
The compound having a polyoxyalkylene group shown in Table 2 was prepared by a known method. Further, Neoscore FW-425 (2.5 mol EO adduct NaOH neutralized product of 2-ethylhexanol phosphate ester) manufactured by Toho Chemical Industry Co., Ltd. was used as the phosphate ester deinking agent.

(Component C Comparative Example Compound)
In order to compare the performance with terpene alcohols, the comparative compounds shown in Table 3 were used. Moreover, what was manufactured by the well-known method was used for compounds other than the commercial item shown in Table 1.

(Component D Example Deinking Agent)
Component A and component B were used in combination in the formulation shown in Table 4. “Combination” in the table indicates that each component was not mixed, but was added at the weight ratio shown in the table, and was used for the test. “Combination” was the weight ratio indicated for each component in the table. It shows that it added to what was mixed beforehand by and was used for the test.

(Component E Comparative Example Deinking Agent)
Component B and component C were used in combination in the formulation shown in Table 5. “Individual” in the table indicates that the deinking agent described in the table was added alone and used for the test.

Deinking test method 1
Raw paper is cut into 3cm x 3cm and placed in a desktop disintegrator. Caustic soda is 1.5% by weight (against old paper), No. 3 sodium silicate is 3% by weight (against old paper), and 35% hydrogen peroxide is 3% by weight. % (Against used paper), after adding the deinking agent shown in the examples or comparative examples so that the total amount becomes 0.2 wt% (versus used paper), water is added to make the used paper concentration 5 wt%, After raising the temperature to 55 ° C., it was disaggregated for 15 minutes. After the disaggregation and aging at the same temperature for 2 hours, a test material (hereinafter, a material before deinking) was obtained.
After diluting the obtained pre-deinking raw material to a pulp concentration of 1% by weight, it is subjected to a flotation treatment for 10 minutes using an MT5L floatator manufactured by IHI Voith Paper Technology Co., Ltd. ) The obtained raw material after deinking was adjusted to a concentration of 0.5% by weight, adjusted to pH 5.0 with aluminum sulfate, and a handsheet was prepared with a sheet machine defined in JIS P-8209. Further, the pulp subjected to the flotation treatment was washed three times with 200 times the amount of ion-exchanged water. A handsheet was prepared in the same manner for this pulp (fully washed pulp).

Deinking test method 2 (Exploitation white water adjustment)
Extracted white water (hereinafter, white water) was obtained by dehydrating and concentrating the post-deinking raw material obtained in Deinking Test Method 1 to 10%.

Deinking test method 3 (Water cycle test)
The raw material before deinking obtained by the deinking test method 1 was diluted to 1% with the white water obtained by the deinking test method 2, and then the deinking test was performed in the same manner as the deinking test method 1. This test is based on the assumption that water is circulated in actual equipment.

Deinking test method 4 (performance evaluation)
After the handsheet is dried, the ISO whiteness is measured according to the method defined in JIS P-8148, and the number of inks having a diameter of 20 μm or more existing in a field of view 100 mm ² is measured using an image analysis apparatus for the completely washed pulp. Was measured.

1. Deinking newspaper waste paper Using the method described in Deinking Test Method 1 using raw material wastepaper consisting of 60% by weight newspaper wastepaper and 40% by weight insert advertisement, the method described in Deinking Test Method 4 was used for evaluation. Carried out.

2. Deinking high-quality waste paper Using the raw waste paper consisting of 50% by weight colored waste paper and 50% by weight imitation waste paper, the test described in Deinking Test Method 1 was performed, and the evaluation was performed using the method described in Deinking Test Method 4. Carried out.

3. Deinking of hard-to-deink waste paper Using raw material waste paper consisting of 80% by weight of PPC waste paper and 20% by weight of UV ink printed waste paper, the test was performed according to the method described in Deinking Test Method 1, and was described in Deinking Test Method 4. Evaluation was carried out by the method.

4). Water Circulation Test A test was performed by the method described in Deinking Test Method 3 using raw paper consisting of 60% by weight newspaper wastepaper and 40% by weight insert advertisement, and the evaluation was performed by the method described in Deinking Test Method 4.

From the results of Table 6, it can be seen that by adding a compound having a terpene alcohol and a polyoxyalkylene group in the process, the ISO whiteness after flotation is greatly improved, and high flotation properties are obtained. In particular, the tendency to show the highest effect when combined with a higher alcohol AO adduct was confirmed.
Further, from the results of Tables 8 and 9, it can be seen that the deinking method of the present invention has a high deinking effect on various used papers called so-called hard-to-deink old paper. Table 9 shows the results of the irrigation cycle test. In general, when the irrigation cycle is performed, the quality tends to be lower than that of the one-pass test, but by adding a compound having a terpene alcohol and a polyoxyalkylene group in the process. It is possible to suppress the quality deterioration.

Claims (3)

In the process of producing deinked pulp ink contained in the waste paper raw material and deinking processes, deinking method characterized by adding a compound having a terpene alcohols and polyoxyalkylene groups in the process. Deinking comprising (a) terpene alcohols and (b) a compound having a polyoxyalkylene group, the weight ratio of which is (a) :( b) = 1: 99 to 99: 1 Agent. (B) The deinking agent according to claim 2, wherein the compound having a polyoxyalkylene group is a compound represented by the following general formula (1).
R ¹ —O— (AO) p—H (1)
(Wherein R ¹ represents an alkyl group having 1 to 24 carbon atoms, an alkenyl group, or an aryl group having 6 to 30 carbon atoms, AO represents an oxyalkylene group having 2 to 4 carbon atoms, and p is an integer of 1 to 200) .)