JP2999287B2 - Deinking agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deinking agent used for recycling used paper such as newspapers, magazines and OA used paper. More specifically, a deinking agent that can obtain a deinked pulp having a high b value and a small amount of unstripped ink when deinking a newspaper, magazine, OA waste paper, etc. by a flotation method, a cleaning method or a compromise method thereof. About.

[0002]

BACKGROUND OF THE INVENTION Newspapers,
Recycling of magazines, OA waste paper, and the like has been practiced for a long time, but recently, in conjunction with global environmental issues such as protection of forest resources and garbage disposal, the effective use of waste paper is increasing in importance. In addition, the use of deinked pulp has been advanced to higher-grade pulp as seen in the example of used newspaper to medium-grade paper. On the other hand, recently used paper is becoming more severe from the viewpoint of deinking due to changes in printing technology, printing method, printing ink components, and the like. Therefore, in order to further promote deinking, improvements have been made to the apparatus. Chemicals conventionally used to separate and remove ink and other impurities from waste paper include alkaline agents such as caustic soda, sodium silicate, sodium carbonate, and sodium phosphate, hydrogen peroxide, hyposulfite, and hypochlorous acid. Bleaching agents such as salts, sequestering agents such as EDTA and DTPA, and anionic surfactants such as alkylbenzene sulfonates, higher alcohol sulfates, α-olefin sulfonates, and dialkyl sulfosuccinates as deinking agents. Nonionic activators such as ethylene oxide adducts of higher alcohols, alkylphenols and fatty acids, and alkanolamides have been used alone or in combination of two or more. However, these deinking agents have high foaming properties in the flotation process, but have low ink collecting ability.The cleaning method has a low detergency, and the high foaming properties prevent foaming problems in drainage treatment. And resulted in only low grade deinked pulp. Furthermore, because there is dullness even with high whiteness,
In order to eliminate the use of deinked pulp (reduction in the amount of paperboard used below and below, reduction in the amount used in newspapers, etc.) and dullness, the amount of bleach used had to be increased. In order to obtain a deinked pulp having a dull color and a bright color tone, the b value of the Hunter color difference type Lab display system may be increased. The deinked pulp having a high b value has a high removal rate of fine ink of 4 μm or less. If the b value is high, the color tone of the pulp becomes bright, so that the use amount of bleach such as hydrogen peroxide can be reduced, high blending of deinked pulp, and use for one-grade applications are possible.

[0003] There are two methods for increasing the b value, such as a method of efficiently removing fine ink of 4 µm or less as described above or a method of using a large amount of alkalis.
However, the latter has the disadvantage that sticky (adhesive) increases, drainage load increases, and pulp becomes brittle. There are some examples of the former technique for collecting and removing fine ink of 4 μm or less, but none of them is effective.

[0004] Higher fatty acids have long been known as deinking agents having a large ink collecting ability. For example, Japanese Patent Registration No. 80988, Japanese Patent Registration No. 82089, and Japanese Patent Registration No. 83901 disclose the use as a deinking agent having excellent ink collecting ability when used alone. Also, JP-A-51-13762, JP-A-53-130309, and JP-A-54-6840.
No. 3 discloses that more excellent effects can be obtained when used in combination with another surfactant.

[0005] Subsequently, with the development of technology, the invention of a high-performance deinking agent comprising a compound to which an alkylene oxide such as ethylene oxide or propylene oxide was added to improve the whiteness of deinked pulp remarkably was made. JP-A-58-109696, JP-A-59-13
0400, JP-A-63-303190).

However, even with the use of the deinking agents disclosed in these techniques, it was not possible to obtain high b-value deinked pulp. Further, when a conventionally known higher fatty acid or a salt thereof is used, there is a drawback that a large amount of unstripped ink is present.

[0007]

Means for Solving the Problems The present inventors have demonstrated excellent ink removing ability, good operability, especially high b-value and high whiteness in the flotation method, the washing method and their compromise method. As a result of intensive research to develop a deinking agent capable of obtaining deinked pulp with less unstripped ink, it was surprisingly found that the above-mentioned drawbacks could be overcome by using a specific ester compound. The present invention has been completed.

Namely, the present invention is the general formula (1) esters represented by compounds intended to provide a deinking agent containing as a main component.

[0009]

Embedded image

(Wherein R ₁ represents a rosin skeleton, R ₂ represents a rosin skeleton or an alkyl, alkenyl, alkynyl, cycloalkyl or aryl group having 1 to 23 carbon atoms. AO represents a carbon number. It represents 2 to 4 alkylene oxides, and n is 1 to 200.) The functions required for the deinking agent include ink releasability due to a decrease in the interfacial tension between cellulose and ink, and prevention of reattachment of the ink released from cellulose. Properties, ink adsorbability to air bubbles, and appropriate foaming properties. The deinking agent must have these four functions in a well-balanced manner. The ester compound of the present invention is particularly excellent in the above.

It is very important that the ester compound represented by the general formula (1) according to the present invention satisfies the formula. Can not.

It is important that the ester compound used as the deinking agent of the present invention is a diester compound type. As a similar ester compound, there is a monoester type compound disclosed in JP-A-63-303190.
Such a monoester type compound cannot sufficiently exhibit the effects of the present invention.

The present inventors have studied the composition of the alkylene oxide adduct of abietic acid, and have found that it is composed of a diester type, a monoester type, or an alkylene oxide homopolymer or copolymer.
Each component was separated and collected by preparative gas chromatography, and the deinking effect of each component was examined.As a result, the diester type efficiently collects submicron fine ink, and has excellent ink peelability from cellulose. I found that. Furthermore, it has been found that compounds having a rosin skeleton other than abietic acid surprisingly give similar results. In the diester type molecular structure, one of the hydrophobic groups
(R ₂ ) is an alkyl group having 1 to 23 carbon atoms, an alkenyl group,
It has been found that the effects of the present invention can be exerted even with an alkynyl group, a cycloalkyl group or an aryl group.

In the general formula (1), R ₁ is a rosin skeleton, wherein the rosin skeleton is abietic acid, dehydroabietic acid, neoabietic acid, isopimaric acid, parastolic acid, pimaric acid, levopimaric acid, seco It indicates a substituent derived from a carboxylic acid alone or a mixture thereof such as dehydroabietic acid, dihydroabietic acid, and tetrahydroabietic acid. These are constituents of unmodified rosin and modified rosin.

Rosins are classified into three types, tall oil rosin, gum rosin, and wood rosin, according to the manufacturing method. Tall oil rosin is obtained by fractionating crude tall oil obtained by decomposing skimming, which has floated by salting out digested black liquor by-produced during the production of kraft pulp, with dilute sulfuric acid. Gum rosin is obtained by damaging the pine trunk and removing turpentine oil from the raw pine resin leached from it. Wood rosin is obtained by further solvent fractionation of the solvent extracted from pine stump chips. The hydrogenated product is obtained by hydrogenating these at a high temperature and a high pressure under a noble metal catalyst to reduce double bonds. Further, the disproportionate can be obtained by heating rosin at a high temperature using a noble metal catalyst or a halogen catalyst. Tall oil rosin, gum rosin, polymerized rosin obtained by chemically modifying wood rosin, maleated rosin, and aldehyde-modified rosin are also used. When tall oil rosin, gum rosin, and wood rosin are treated under an acidic catalyst, a polymerized rosin can be obtained. When a Diels-Alder reaction is performed using maleic anhydride as a dienophile, maleated rosin is obtained. Furthermore, when formaldehyde is allowed to act on rosin under an acidic catalyst, an aldehyde-modified rosin is obtained by a Prince reaction.

Since R ₁ in the general formula (1) is a large hydrophobic group such as a rosin skeleton, it has an effect of collecting fine ink of submicron or less.

R ₂ in the general formula (1) is, in addition to the rosin skeleton described above, an alkyl group or alkenyl group having 1 to 23 carbon atoms,
Examples include an alkynyl group, a cycloalkyl group and an aryl group. If the carbon number is less than 1, a deinked pulp having a high b value cannot be obtained. On the other hand, when the number of carbon atoms exceeds 23, the releasability of the ink from the cellulose is reduced, so that the remaining amount of the unreleased ink is large, and only a deinked pulp having a poor appearance can be obtained.

Specific examples of the carboxylic acid having a portion corresponding to R ₂ in the general formula (1) include acetic acid, propionic acid, propic acid, butyric acid, isobutyric acid, tetrolic acid, valeric acid,
α-methylbutyric acid, isovaleric acid, trimethylpropanoic acid,
2-pentylic acid, allylic acid, caproic acid, 2-methylpentanoic acid, 3-methylpentanoic acid, 4-isocaproic acid, 2-hexyneic acid, sorbic acid, 2-hexenoic acid,
-Hexenoic acid, 4-hexenoic acid, 5-hexenoic acid, heptanoic acid, 2-heptenoic acid, 3-heptenoic acid, 5-heptenoic acid, 6-heptenoic acid, 2-heptinic acid, 6-heptinic acid, caprylic acid, 2-ethylhexanoic acid, 2-octenoic acid, 3-octenoic acid, 2-octic acid, 7-octic acid, 2-methyl-2-heptenoic acid, cyclohexylacetic acid, 2-fluorovaleric acid, 2-fluorocaproic acid, 2
-Fluoroenanic acid, 2-chlorocaprylic acid, 2-bromovaleric acid, 2-bromocaproic acid, 2-bromoenanic acid, 2-bromocaprylic acid, 5-chlorovaleric acid, 2-
Hydroxyvaleric acid, 2-hydroxycaproic acid, 2-hydroxycaprylic acid, 2-hydroxypelargonic acid, 2
-Hydroxyundecanoic acid, 3-hydroxycaprylic acid, 6-hydroxycaproic acid, 7-hydroxyenanthic acid, 8-hydroxycaprylic acid, 2-methyl-hydroxyenantic acid, 2-hydroxy-3-pentenoic acid,
-Hydroxy-3-pentenoic acid, 4-hydroxy-4-
Pentenoic acid, 5-hydroxy-2,4-pentadienoic acid,
2,3-dihydroxycaproic acid, 2,3-dihydroxyenanthic acid, 2,3-dihydroxycaprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid,
Margaric acid, stearic acid, oleic acid, elaidic acid, linoleic acid, linoleic acid, stearolic acid, ricinoleic acid, ricinoelaidic acid, nonadecanoic acid, arachidic acid, heneicosanoic acid, behenic acid, brassic acid,
Erucic acid, trichosanoic acid, tetracosanoic acid, coconut oil, fatty acids, tallow fatty acids, palm oil fatty acids, tall oil fatty acids,
Rapeseed oil fatty acids, fish oil fatty acids or their semi-hardened or hardened fatty acids, cyclohexylpropionic acid, cyclohexylbutyric acid, cyclohexylvaleric acid,
α-cyclohexylcaprylic acid, α-cyclohexylpelargonic acid, α-cyclohexylcapric acid, α-cyclohexylundencanic acid, α-cyclopentylcaprylic acid, α-cyclopentylcapric acid, benzoic acid, methylbenzoic acid, etc. .

AO in the general formula (1) is an alkylene oxide having 2 to 4 carbon atoms, such as ethylene oxide (hereinafter referred to as EO), propylene oxide (hereinafter referred to as PO), and butylene oxide (hereinafter referred to as BO). . Particularly preferred are EO and PO having 2 and 3 carbon atoms. More preferably, EO and
PO mixture, in which case the molar ratio is EO / PO = 0.5 /
1-5 / 1 is preferred. It is important that n is 1 to 200. Particularly preferred is 10 to 120. n is 1
If it is smaller, the amount of unstripped ink increases, and only pulp with poor appearance is obtained. If n exceeds 200, foaming increases in the flotation step, pulp effluent increases, and the yield decreases significantly. In order to maintain the yield, the amount of the deinking agent added must be reduced, and as a result, deinked pulp having a high b value cannot be obtained.

The ester compound represented by the general formula (1) according to the present invention can be obtained by a known method.
For example, an addition reaction of rosin with an alkylene oxide is performed under an alkali catalyst. Next, a dehydration reaction is carried out using stannous oxide as a catalyst and the addition reaction product and rosin in approximately equimolar amounts to obtain a main component.

The deinking agent of the present invention has both ink cohesiveness and ink releasability which could not be obtained by a conventionally known compound, and can provide an excellent deinking effect even when used alone.
If necessary, a conventionally known deinking agent can be used in combination. When a conventionally known deinking agent is used in combination, the compounding ratio of the present invention / conventional product is preferably from 95/5 to 5/95, particularly preferably from 70/30 to 30/70 by weight. Conventionally known deinking agents include, for example, higher alcohol sulfates, polyoxyalkylene higher alcohol sulfates, alkylbenzene sulfonates, higher fatty acids and salts thereof, and alkylene oxide adducts of higher alcohols and alkylphenols.

When the deinking agent of the present invention is added to any of the steps, higher quality deinked pulp can be obtained. Generally, the deinking agent is added to either or both the mixing step and the flotation step. The deinking agent of the present invention conforms to this. When divided addition in each step, it can be added to each step of pulping, kneading, dispersing, chemical mixing, refining,
The split ratio of the deinking agent in the pre-process and post-process is 10/90 to 90/10
(Weight ratio) is preferred. Particularly preferably 40 / 60-60 /
40 (weight ratio). The amount of the deinking agent added should not be impaired in operability and should be economical.
0.03 to 1.0% by weight is preferred.

[0023]

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

Example 1 This example is an example of batch addition of a deinking agent in a pulping step. The used newspaper collected in the market is shredded to 2 x 5 cm, and a certain amount is placed in a tabletop disintegrator, in which water and caustic soda (based on raw materials) 0.8% (by weight, the same applies hereinafter), sodium silicate (based on raw materials) 2.2%, 30% aqueous hydrogen peroxide (based on raw material) 3.5%, various deinking agents (based on raw material) 0.5% shown in Table 1, and pulp concentration
After disaggregation at 15% at 45 ° C for 12 minutes, the mixture was aged at 55 ° C for 120 minutes. Dehydration was performed to 23% with a high-speed dehydrator, and kneading treatment was performed with a biaxial lab kneader having a rotation speed of 300 rpm. Thereafter, water was added to dilute the pulp to a pulp concentration of 4%, and the mixture was disintegrated again with a desktop disintegrator for 30 seconds. Thereafter, the mixture was diluted with water to a pulp concentration of 1%, and 0.5% of calcium chloride (based on raw material) was added, followed by a flotation treatment at 30 ° C. for 10 minutes. Next, the pulp slurry after flotation was concentrated to 4% concentration with an 80-mesh wire, and diluted with water to 1% concentration to prepare a pulp sheet using a TAPPI sheet machine. The hardness of the used water was 5 ° dH, and the hardness was
CaCl ₂ and MgCl ₂ were used and adjusted so that Ca / Mg = 8/2 (molar ratio). The b value of the obtained pulp sheet was measured with a side colorimeter (diffuse reflection type), and an image analyzer (× 10
In 0), the number of unstripped inks was measured. Table 1 shows the results. Here, the b value refers to the b value in the Lab color system of the Hunter color difference formula, and the relationship with the tristimulus value XYZ is as follows.

[0025]

(Equation 1)

As can be seen from this equation, the b value is a function of Y and Z, with a positive value representing yellowish intensity and a negative value representing blueish intensity.

[0027]

[Table 1]

Example 2 This example is an example of the divisional addition of the deinking agent in the pulping step and the chemical mixing step. 2 x 5 used newspapers collected in the city
After chopping into pieces, a certain amount was put into a tabletop disintegrator, into which water and caustic soda (based on raw materials) 0.2%, and various deinking agents (based on raw materials) 0.1% shown in Table 2 were added. %, 50 ℃,
After fibrillation for 15 minutes, dehydrate the pulp to 18% concentration, and add 0.6% of sodium hydroxide (based on raw material), 2.2% of sodium silicate (based on raw material), 3.5% of 30% hydrogen peroxide (based on raw material), Table 2
Each of the various deinking agents (based on the raw material) shown in (1) was added at 0.2%, the pulp concentration was adjusted to 15% with water, and mixed for 1 minute using a desktop disintegrator. 55
The ripening treatment was performed at a pulp concentration of 15% at 120 ° C for 120 minutes. Then add water to a pulp concentration of 4%, and add 3
Disintegration treatment for 1 minute, further adding water to reduce the pulp concentration to 1%
And add 0.5% of calcium chloride (based on raw material)
A flotation treatment was performed at 30 ° C. for 10 minutes. Then
The pulp slurry after flotation was concentrated to 6% concentration with an 80 mesh wire, and then diluted to 1% concentration by adding water, and a pulp sheet was prepared using a TAPPI sheet machine. The hardness of the used water was 5 dH and the hardness was Ca
It was adjusted so that Ca / Mg = 8/2 (molar ratio) using Cl ₂ and MgCl ₂ . The b value of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and an image analyzer (× 10
In 0), the number of unstripped inks was measured. Table 2 shows the results.

[0029]

[Table 2]

Example 3 This example is an example in which the deinking agent is added separately in the pulping step and the kneading step. The used newspaper collected in the market is cut into 2 x 5 cm pieces, and a certain amount is placed in a desktop disintegrator, in which water and caustic soda (based on raw materials) are 0.2%, and various deinking agents shown in Table 3
Add 0.2% (based on raw material), disintegrate the pulp at 5% at 50 ° C for 15 minutes, dehydrate to a pulp concentration of 28%, and add 0.6% caustic soda (based on raw material) and sodium silicate (based on raw material). ) 2.
2%, 30% hydrogen peroxide solution (based on raw material) 3.5%, and various deinking agents (based on raw material) 0.2% shown in Table 3 were added.
It was adjusted to 5%, and kneading treatment was performed with a biaxial lab kneader having a rotation speed of 300 rpm. After that, aging treatment is performed at 55 ° C for 120 minutes at a pulp concentration of 25%, and then a pulp concentration of 4%
Was added to the mixture, and the mixture was subjected to a defibration treatment for 3 minutes using a desktop disintegrator, further diluted with water to a pulp concentration of 1%, and subjected to a flotation treatment at 30 ° C. for 10 minutes. Next, the pulp slurry after flotation was treated with 80 mesh wire for 6 hours.
After concentrating to 1% concentration, add water to dilute to 1% concentration,
A pulp sheet was prepared using a PPI sheet machine. still,
The hardness of the water used was 10 ° dH, the hardness was CaCl ₂ , Mg
It was adjusted to be Ca / Mg = 8/2 (molar ratio) using Cl ₂ . The b value of the obtained pulp sheet was measured by a colorimeter (diffuse reflection type), and the number of unstripped ink was measured by an image analyzer (× 100). Table 3 shows the results.

[0031]

[Table 3]

Example 4 This example is an example of the addition of the deinking agent in the pulping step and the flotation step. After the used newspaper collected in the city is cut into 2 x 5 cm pieces, a certain amount of the waste paper is put into a table disintegrator, and water and caustic soda (based on raw materials) are 0.2%. Various deinking agents shown in Table 4 (based on raw materials) 0.2% was added, pulp concentration was 15%, defibration was performed at 45 ° C for 12 minutes, and ripening was performed at 55 ° C for 120 minutes. After that, dehydrate to 23% with high-speed dehydrator, and use caustic soda (based on raw material) 0.6
%, Sodium silicate (based on raw material) 2.2%, and 30% aqueous hydrogen peroxide (based on raw material) 3.5%. The pulp concentration was adjusted to 22% with water, and the mixture was mixed for 1 minute using a desktop disintegrator. After that, rotation speed 300r
The kneading process was performed using a two-axis lab kneader of pm.
Thereafter, water was added to dilute the pulp to a pulp concentration of 4%, and the mixture was disintegrated again with a desktop disintegrator for 30 seconds. Thereafter, 0.3% of various deinking agents (based on raw materials) shown in Table 4 were added, and the pulp concentration was adjusted to 1% with water.
And then subjected to a flotation treatment at 30 ° C. for 10 minutes. Next, the pulp slurry after flotation was
After concentrating to 4% concentration with a mesh wire, add water and add
%, And a pulp sheet was prepared using a TAPPI sheet machine. The hardness of the water used was 40 ° dH, and the hardness was CaCl ₂ or MgCl ₂ , and Ca / Mg = 8/2.
(Molar ratio). The b value of the obtained pulp sheet was measured by a colorimeter (diffuse reflection type), and the number of unstripped ink was measured by an image analyzer (× 100). Table 4 shows the results.

[0033]

[Table 4]

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D21C 5/02

Claims (1)

(57) [Claims] 1. An ester compound represented by the general formula (1)
Deinking containing as a main component. Embedded image (Wherein, R ₁ represents a rosin skeleton, R ₂ represents a rosin skeleton or an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group or an aryl group having 1 to 23 carbon atoms. AO represents 2 to 4 carbon atoms. Wherein n is 1 to 20
0. )