JPH0742671B2 - Deinking agent for recycled waste paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a deinking agent used for recycling used paper such as newspapers, magazines and books. More specifically, it relates to a deinking agent capable of producing a recycled pulp having a high whiteness and a small number of residual inks when deinking newspapers, magazines, books, etc. by a flotation method and a flotation and washing eclectic method.

[Background of the Invention] Recycled printed paper such as newspapers and magazines has been used for a long time. Especially, while advanced use of deinked pulp has recently been promoted, it is effective to reduce the papermaking cost. Utilization is becoming increasingly important.

The recycling of waste paper has many advantages from the viewpoints of energy conservation measures, municipal waste measures, and forest resource protection measures.

On the other hand, recently used paper is becoming more severe from the viewpoint of deinking due to changes in printing technology / printing method, changes in printing ink components, and so on. Has been added.

The deinking agent is roughly classified into a disperse type deinking agent (mainly a nonionic surfactant) for the purpose of removing the desorbed ink in a finely dispersed state outside the system. There is an aggregating deinking agent for the purpose of removing the ink to the outside of the system in a state of aggregating the ink to some extent.

The conventionally known chemical substances used as the deinking agent for recycling recycled paper are anionic surfactants such as alkylbenzene sulfonate, alkyl sulfate, α-olefin sulfonate, dialkyl sulfosuccinate and higher fatty acid salt, and higher alcohol ethylene oxide addition. Nonionic surfactants such as compounds, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, fatty acid amide ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, ethylene oxide adducts of fats and oils, higher alcohol ethylene oxide propylene oxide adducts, etc. Examples thereof include zwitterionic surfactants such as agents, amine oxides and alkyl betaines.

[Problems to be Solved by the Invention] However, the deinking efficiency in the flotation process is not necessarily high with these chemical substances and their blends, etc., and there is a demand for obtaining recycled paper with high whiteness and low residual ink. On the other hand, it is not always satisfactory.

In particular, when a fatty acid that is solid at room temperature is used, the cohesiveness is excellent, but so-called beard easily occurs, and the energy cost for melting is very high.

Further, when the fatty acid salt is added as it is or in the form of an aqueous solution, the whiteness of the recycled pulp is inferior, and when a liquid fatty acid is used at room temperature, foaming of the surfactant used as a foaming agent is caused. However, the whiteness of the recycled pulp does not increase because the separated ink cannot be sufficiently removed outside the system.

Further, ordinary nonionic surfactants are excellent in ink dispersibility, detergency and foaming power, but are inferior in ink cohesive power, and thus the problem that the whiteness of recycled pulp does not always rise is a problem. is there.

In this way, no chemical substance has been found that has all of the releasability of ink from the paper in the waste paper disaggregation process, the cohesiveness, the high foaming property in the flotation process, and the high ink collecting property, and there is no specific chemical substance. A general method is to use two or more kinds of chemical substances in combination or in combination. However, even if the deinking method using this composition has some effect, it is not always a satisfactory method.

[Means for Solving Problems] Then, as a result of intensive studies to find a deinking agent which does not have the above-mentioned drawbacks, the present inventors have found that the compound represented by the following general formula (I) satisfies this. The present invention has been completed.

That is, the present invention provides a deinking agent for recycling used paper, which contains a compound represented by the following general formula (I).

General formula (I) (In the formula, R ₁ is an alkyl group or an alkenyl group having 5 to 30 carbon atoms, _one of R ₂ and R ₃ is an alkyl group having 1 to 8 carbon atoms, and the other is hydrogen, ammonium, an alkali metal or an alkanol. The compound represented by the general formula (I) of the present invention is obtained by converting an addition reaction product of an olefin and maleic anhydride into a monoester or a salt thereof. Any method may be used as long as it is produced. As a conventionally known method, for example, olefin and maleic anhydride are heated at 150 to 250 ° C.
The addition reaction product obtained by heating under the following conditions is reacted with alcohol to form a monoester, and this monoester is reacted with caustic soda, ammonium hydroxide, alkanolamine, etc. to obtain an alkali metal salt, ammonium salt, or alkanolamine salt. There is a method of doing. In this case, the olefins can be used as a mixture of those having different carbon numbers, and can also be used as a linear or branched type.

Of the compounds represented by the general formula (I), when one of R ₂ and R ₃ is hydrogen, it is insoluble in water, but when added to a pulp slurry containing alkali, alkali metal is immediately added. Since it becomes a salt, it can be easily solubilized.

[Action] A feature of the compound represented by the general formula (I) of the present invention is that one of the acid groups is esterified and the other is a fatty acid or a salt thereof, which is nonionic in one molecule. , Having both anionic properties.

Therefore, it has ink cohesiveness, dispersibility, and high foaming properties, which are necessary properties to be provided as a deinking agent, and therefore exhibits excellent deinking performance even when this compound is used alone. Is. In addition, unlike fatty acids and the like, they are liquid and therefore easy to handle.

The deinking agent of the present invention may be added to any step of waste paper disintegration step and ripening tower, and the addition amount varies depending on the paper quality of the waste paper and the type of ink, but is generally 0.1 with respect to the raw waste paper.
It is preferable to use ~ 0.8% by weight, more preferably
0.2 to 0.6% by weight.

INDUSTRIAL APPLICABILITY In the present invention, excellent effects can be obtained even when the compound represented by the general formula (I) is used alone as a deinking agent, and particularly, an alkyl group or an alkenyl group having 12 to 20 carbon atoms, R ₁ or R ₂ and
One of R ₃ is an alkyl group having 1 to 3 carbon atoms,
On the other hand, compounds that are hydrogen or sodium are superior.

Further, compounds having different carbon numbers of R ₂ or R ₃ may be used in combination, or may be used in combination with another deinking agent.

Further, polyvalent metal salts such as calcium chloride, magnesium chloride, magnesium hydroxide, calcium hydroxide, aluminum sulfate and the like can be used in combination.

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

Examples 1 to 12 The compounds according to the present invention shown in Table 1 below were used as deinking agents, and J.TAPPI (Paper and Pulp Technology Association) deinking test method (No. 39-8) was used.
A deinking test was conducted by the method according to 2).

The test method is 70% by weight of daily newspaper, Asahi, and Yomiuri newspaper (all 1-2 months after printing) and 30% by weight of leaflets.
The used paper consisting of and is shredded, a certain amount of which is put into a table disintegrator, and hot water, sodium hydroxide 2.0% by weight (to the used paper), sodium silicate 4.0% by weight (to the used paper), Hydrogen peroxide (purity) 2.0% by weight (vs. raw paper),
0.2% by weight of the deinking agent shown in Table 1 (against used waste paper) was added, pulp concentration was 5% by weight, disaggregation was performed at 60 ° C for 10 minutes, and then aging was performed at 50 ° C for 1 hour.

Then, water was added to dilute the pulp concentration to 1% by weight, and a flotation treatment was performed at 30 ° C. for 10 minutes using a test floatator. After concentrating the pulp slurry after flotation to 10% by weight, water was added to dilute it to a concentration of 1% by weight, and hand-papermaking was performed with a J.TAPPI standard machine to produce a pulp sheet. For this pulp sheet, the whiteness was measured using a colorimetric color difference meter (Z-1001DP type manufactured by Nippon Denshoku Co., Ltd.), and an image analysis device (Luzex 2D type manufactured by Nikon Co., Ltd.) (x80)
Was used to measure the number of remaining inks.

The evaluation results are summarized in Table 1.

Comparative Examples 1 to 4 Commonly used as commercial products C ₁₃ H ₂₇ COOH, C ₁₂ H ₂₅ O (EO) ₁₀ H, HOOC (CH ₂ ) ₄ COOH 4
For each type, deinking property was evaluated under the same conditions and methods as those in the above-mentioned examples.

The results are summarized in Table 1.

[Effects of the Invention] The deinking agent according to the present invention has excellent deinking performance because it has both nonionic and anionic properties in one molecule. Therefore, the recycled paper is whiter than the conventional deinking agent.

Further, since it is liquid, it is easy to handle, and heating for melting is not required.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masanori Yoshikawa 4-4-11 Minami, Kasukabe City, Saitama Prefecture (56) References JP 60-146091 (JP, A) JP 1-306691 (JP, A) )

Claims (1)

[Claims] 1. A general formula (I) (In the formula, R ₁ is an alkyl group or an alkenyl group having 5 to 30 carbon atoms, _one of R ₂ and R ₃ is an alkyl group having 1 to 8 carbon atoms, and the other is hydrogen, ammonium, an alkali metal or an alkanol. A deinking agent for recycling used paper containing a compound represented by an amine.