JP2645208B2 - Deinking agent for recycled paper - 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 and magazines. More specifically, when deinking newspapers, magazines, etc. by the flotation method, deinked pulp with high whiteness and a small number of remaining inks can be obtained. About black ink.

[0002]

2. Description of the Related Art
As a deinking agent, for example, polyethylene alkyl ether is widely used because it has all the essential functions such as ink removal from waste paper, ink removal and foaming power required by flotation systems. ing. However, today's conventional deinking agents, such as the sophistication of the required quality of recycled paper users and the diversification of ink used in recovered waste paper,
There are various situations that cannot be dealt with.

For example, when a waste paper that has been thermally degraded, such as that found in raw materials exposed for a long period of time in summer, is treated in the deinking process, a problem occurs in that the amount of ink remaining in the final product increases. As a cause, it is considered that the quality of the ink is changed by heat or oxygen, and the binding between the ink and the paper is strengthened. Such heat-degraded waste paper is ineffective at all with conventional deinking agents, and is inevitably costly, such as converting other chemicals into increased-shear systems.

[0004] In recent years, the water use system of factories has been mainly closed using circulating water for the purpose of environmental measures or reduction of running cost.
When the closed state of the deinking process water is strengthened, inks, paints, or chemicals derived from process chemicals from the raw materials flow into the process from the recovered water. In particular, when the deinking agent is recycled in the process through the circulating water, the foaming power of the process itself becomes larger than necessary, causing foam trouble in the drainage pit in flotation. Further, when residual foam is generated in the papermaking process, foam in the slurry impedes dehydration, resulting in poor drainage and, in the worst case, paper breakage.

[0005]

Means for Solving the Problems In view of such a background, the present inventors have conducted intensive studies and as a result, have found that by using specific three components, the permeability between paper and ink, ink removability and ink removal properties can be improved. While maintaining the foaming properties to some extent, the foamed foams were quickly broken to enhance the defoaming properties, thereby completing the deinking agent of the present invention.

That is, the present invention provides the following general formula (A):
A deinking agent containing the compounds represented by (B) and (C).
Thus, compounds represented by general formulas (A), (B) and (C)
In the-(AO) _l -,-(AO) _m- and- (AO) _n -chains
Is an essential condition that the presence of ethylene oxide polymer
Ethylene oxa in alkylene oxide polymer
The proportion of the polymer is 30 to 80 mol%, and the general formula
The weight ratio of the compounds represented by (A), (B) and (C) is
(A): (B): (C) = 20-40: 30-70: 20-40
That relates to a deinking agent, characterized in that.

[0007] (Wherein, R ₁ , R ₂ , R ₃ ; a group AO selected from an alkyl group or an alkenyl group having 8 to 24 carbon atoms; an oxyalkylene group l, m, n having 2 to 4 carbon atoms; 10 to 100) Indicates the integer of.)

In Japanese Patent Publication No. 64-11756, the general formula
A deinking agent containing the compounds represented by (A) and (B) (hereinafter referred to as A component and B component, respectively) is described. It had problems. However, in the present invention, it has been found that the above-mentioned effect of enhancing penetration and defoaming power is improved only by newly adding a compound represented by the general formula (C) (hereinafter, referred to as component C).

The weight ratio of the A, B, and C components is A component: B component: C component = 20-40: 30-70: 20-40.

In the components A and B, R _{1 to} R ₃ have 8 to 24 carbon atoms.
Is a group selected from among alkyl groups or alkenyl groups, but if the carbon number exceeds 24, sufficient foaming power cannot be obtained,
Insufficient foaming in flotation and insufficient ink removal. In addition, since the affinity with pulp is insufficient, the permeability between ink and paper is insufficient. When the number of carbon atoms is less than 8, the affinity with the ink is low, so that the ink cannot be completely collected and removed, and only a dull pulp can be obtained.

In the components A, B and C, AO has 2 to 4 carbon atoms.
Alkylene oxide polymer of-(AO) _l- ,
Ethylene oxide is essential for the-(AO) _m- and-(AO) _n -polymer chains, and the proportion of the total alkylene oxide polymer is 30 to 80 mol% . Ethylene oxide in the A Ruki alkylene oxide polymer chain, propylene oxide may be a random polymer in block polymerization, ethylene oxide is required in order to enhance the releasability of the ink and paper. When the number of moles of 1, m and n is in the range of 10 to 100 moles, the permeability between the ink and the paper is improved, and the ink is easily peeled off with a small mechanical force. If the moles of 1, m, and n exceed this range, there are inherent factors that reduce the ink removing effect in flotation and cause bubble trouble.

The C component satisfying the above conditions is an important factor in controlling foaming and defoaming. Especially n is 10
When the amount is within the range of 100 to 100 mol, the foam generated at the same time as the sufficient foaming power is quickly eliminated, and the operability of the foam in the flotation step can be remarkably improved. Specifically, the floss foam discharged from the flotation is quickly defoamed, accumulates due to closing, and does not foam even if the deinking agent flows into the papermaking process, resulting in excessive foaming and paper breakage. Eliminate troubles such as

Therefore, when the ratio of n and ethylene oxide, which determine the structure of the component C, is controlled within an appropriate range, the operability of the foam in the deinking property is excellent as compared with the conventional deinking agent. Improve to the level.

The components A and B can be obtained, for example, by reacting a polymer to which an alkylene oxide has been added with a fatty acid and performing an esterification reaction, or by subjecting the fatty acid to an addition reaction with the alkylene oxide. Specific fatty acids include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, behenic acid, etc., and coconut oil fatty acids, soybean fatty acids, tall oil fatty acids, tallow oil, and tallow oil containing those fatty acids. Fatty acids, fish oil fatty acids, and the like, or fatty acids and synthetic fatty acids obtained from hydrogenated natural products of these fatty acids can be used.

The amount of the deinking agent of the present invention is preferably from 0.2 to 1.0% by weight based on the raw waste paper. Further, the deinking agent of the present invention can be used in combination with a known deinking agent generally used conventionally.

[0016]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A used newspaper collected in the city was shredded to 2 × 5 cm, and a certain amount was put into a tabletop disintegrator, in which water and caustic soda (based on raw material)
1.0% (weight basis, the same applies hereinafter), sodium silicate (based on raw material) 3.
0%, 30% hydrogen peroxide (based on raw material) 3.0%, various deinking agents shown in Table 1 (based on raw material) 0.4%, pulp concentration 5%, 55%
After separating at 20 ° C. for 20 minutes, the mixture was aged at 50 ° C. for 60 minutes. Thereafter, water was added to dilute the pulp concentration to 1.0%, 1.0% of CaCl ₂ (based on raw material) was added, and a flotation treatment was performed at 30 ° C. for 10 minutes. 6 pulp slurry after flotation
After concentration to a concentration of 1%, water was added to dilute the solution to a concentration of 1%, and a pulp sheet was prepared using a standard TAPPI Sagami machine. The whiteness of the obtained pulp sheet was measured with a side colorimeter, and the number of remaining inks was measured with an image analyzer (× 126).

The foam breaking test and the drainage test were performed as follows.・ Bubble breaking test 1. Treat 1% slurry with a lab floatator 2. Collect the discharged foam 3. 200cc of bubble stone in a certain amount (about 50cc) of the discharged liquid
Submerge in a volumetric flask with a stopper. 4. Pass a certain amount of air. 5. Confirm that the height of the bubbles has become constant, and stop the ventilation. 6. Measure the bubble height at that time (H ₀ cm). 7. 60s Observe the state of foam breaking 8. Measure the foam height after _{60 s} (H ₆₀ cm) 9. The foam breaking rate is expressed by the following formula.

[0019]

(Equation 1)

・ Water drainage test 1. Pulp slurry 1.5%, 300ml is standard TAPPI
Add to paper machine 2. Standard TAPPI Add a certain amount of water to paper machine and stir and equalize slurry inside 3. Start dewatering and measure time until slurry turns into sheet 4. Lead to sheet The shorter the time, the better the drainage.

Table 1 also shows the above results.

[0022]

[Table 1]

Note) ・ R ₁ , R ₂ and R ₃ of No. 3 and No. 4 are alkyl groups derived from oleic acid ・-(EO) _x (PO) _y -is EO and PO in the direction of the alkyl group And x
Addition of moles and y moles--(EO / PO _{x / y} )-is a random addition at a mixing ratio of x moles and y moles-Component A R ₁ COO (AO) _l COR ₂ · Component B R ₃ COO (AO ) _m H · Component C HO (AO) _n H

Claims (1)

(57) [Claims] 1. A deinking agent containing a compound represented by the following general formulas (A), (B) and (C):
In the compounds represented by (A), (B) and (C),-
(AO) _l -,-(AO) _m- and- (AO) _n-
The essential condition is that the oxide polymer is present.
Ethylene oxide polymer in side polymer
Is 30 to 80 mol%, and the general formulas (A), (B) and
The weight ratio of the compound represented by (C) is as follows: (A): (B):
(C) = 20 to 40:30 to 70:20 to 40, a deinking agent. (Wherein, R ₁ , R ₂ , R ₃ ; a group AO selected from an alkyl group or an alkenyl group having 8 to 24 carbon atoms; an oxyalkylene group l, m, n having 2 to 4 carbon atoms; 10 to 100) Indicates the integer of.)