JPH0641887A - Deinking agent for recycled waste paper - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] A deinking agent for deinking treatment, which has excellent separation and removal performance of printing ink, and therefore has high whiteness, a small number of residual inks, and an L value of Providing deinking agents that give high recycled pulp. The deinking agent for recycling waste paper according to the present invention has the general formula (I): (In the formula, R represents an alkyl group having 6 to 14 carbon atoms, n represents a number of 2 or 3, PO represents an oxypropylene group, AO represents an oxyethylene group, or an oxypropylene group and an oxybutylene group. An alkylphenol represented by a mixed oxyalkylene group of at least one selected oxyalkylene group and an oxyethylene group, x is 1 to 20, y is 1 to 50, and z is a number of 1 to 50). It is characterized by containing an alkylene oxide adduct of a resin as an active ingredient.

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 waste paper such as newspapers and magazines, and more specifically, it has high whiteness when deinking newspapers and magazines by the floatation method. The present invention relates to a deinking agent which gives a recycled pulp having a small number of residual inks and a high L value.

[0002]

Recycling of waste paper is to disintegrate newspapers, magazines, etc. recovered from the city into pulp fibers, remove printing ink components such as carbon and vehicle, and recover pulp fibers as a raw material for papermaking. The recycling of such waste paper has been carried out since ancient times. In particular, in recent years, against the background of lack of resources and soaring prices thereof, effective utilization of waste paper resources is becoming more important, while on the other hand, recent diversification of printing technology and printing method and changes in printing ink components. Against this background, more effective deinking agents have been demanded.

As a typical one of the deinking methods for recycling such waste paper, the floatation method has been conventionally known. This floatation method is to add a deinking agent to an aqueous slurry of pulp fibers obtained by disintegrating waste paper to separate and agglomerate the ink components from the pulp fibers, and then blow air into the aqueous slurry to form bubbles. In this method, an ink component is attached to the foam to remove the ink component together with the foam. The pulp fiber from which the ink component has been removed in this way is bleached or bleached and used as a papermaking raw material.

In such a floatation method,
Conventionally, various surfactants have been used as the deinking agent, but most representatively, higher fatty acid soaps such as stearic acid soap have long been known. Although this deinking agent has good ink removal performance, it does not completely remove the ink that has flocculated and floated due to the fact that the ink adheres to the device and has a low foaming property, and the ink remains on recovered pulp fibers. have. Furthermore, if a large amount of fatty acid soap is not used, a sufficient deinking effect cannot be obtained and the deinking cost is high.

In order to solve such problems, in recent years, in addition to higher fatty acid soaps, anionic surfactants such as sodium alkylbenzene sulfonate, higher alcohol sulfates, α-olefin sulfonate, dialkyl sulfosuccinate, etc. Nonionic surfactants such as alcohols, alkylphenols and alkylphenol resins, and ethylene oxide and propylene oxide adducts thereof have also been proposed as deinking agents.

For example, Japanese Patent Application Laid-Open No. 55-51981 proposes a deinking agent containing a polyoxyethyleneoxypropylene ether of a higher alcohol, and Japanese Patent Application Laid-Open No. 61-186592 discloses a deinking agent. A deinking agent containing a higher alcohol polyoxyethyleneoxypropylene ether along with a higher fatty acid or a salt thereof has been proposed. Japanese Unexamined Patent Publication (Kokai) No. 63-165592 also proposes a deinking agent containing the above polyoxyethyleneoxypropylene ether of a higher alcohol as one component. Further, for example, JP-A-63-270887.
Japanese Patent Laid-Open Publication No. 2003-242242 proposes a deinking agent containing an alkylene oxide adduct of an alkylphenol resin.

[0007]

Although such a deinking agent is improved in various points as compared with fatty acid soap, it still has a sufficient separation and removal performance of printing ink in the floatation process. None, and in some cases, it is inferior to fatty acid soaps. INDUSTRIAL APPLICABILITY The present invention is excellent in the separation and removal performance of printing ink in the floatation process, and accordingly, in the deinking process of newspapers, magazines and the like by the floatation method, the deinking pulp with high whiteness and a small number of remaining ink It is an object of the present invention to provide a deinking agent that gives

[0008]

The deinking agent for recycling waste paper according to the present invention has the general formula (I).

[0009]

[Chemical 2]

(Wherein R represents an alkyl group having 6 to 14 carbon atoms, n represents a number of 2 or 3, PO represents an oxypropylene group, AO represents an oxyethylene group, or an oxypropylene group and an oxy group. A mixed oxyalkylene group of at least one oxyalkylene group selected from a butylene group and an oxyethylene group is shown, x is 1 to 20, and y is 1 to
50 and z show the number of 1-50. ) The alkylene oxide adduct of the alkylphenol resin represented by

In the above general formula (I), R may be, for example, octyl, nonyl, decyl, dodecyl or the like as a mixture, but is not limited thereto. Further, R may be a mixture of two or more kinds of alkyl groups. Further, according to the present invention, in the general formula (I), x is preferably in the range of 3 to 15, y is in the range of 20 to 40, and z is preferably in the range of 5 to 20.

The alkylene oxide adduct of the alkylphenol resin represented by the above general formula (I) used as a deinking agent in the present invention has a structurally n of 2 or 3 and a relatively high molecular weight. It's a small one, and
It is characterized in that it has an oxypropylene group bonded to a hydroxyl group residue (oxygen atom bonded to an aromatic ring) of an alkylphenol resin and also has a propylene glycol residue at the molecular end. The deinking agent according to the present invention contains such an alkylphenol resin as an active ingredient, and it has an excellent balance between dispersibility and cohesiveness of the ink in the floatation treatment, so that the whiteness is high and the number of remaining inks is small, Moreover, recycled pulp having a high L value can be provided.

The L value is an index showing the whiteness, and the recycled pulp obtained according to the present invention has a high L value and a high whiteness. Therefore, in the paper production, even if the mixing ratio of the waste paper treated pulp is increased. In terms of color tone, it is possible to obtain a paper having the same whiteness as that of so-called virgin pulp.
However, an alkylene oxide adduct of an alkylphenol resin in which n is larger than 3, a alkylene oxide adduct having no propylene glycol residue as a terminal structure, or a residue of a hydroxyl group of an alkylphenol resin (bonded to an aromatic ring) Oxygen atom) to which an ethylene oxide group is bound, or the alkylene oxide addition is a random addition, compared to the deinking agent of the present invention.
Recycled pulp is inferior in whiteness, number of remaining inks and L value.

Further, since the alkylene oxide adduct of the alkylphenol resin used in the present invention is a liquid at room temperature, it can be added as it is to the aqueous system when dissociating the waste paper, so that the energy cost in the deinking treatment is greatly reduced. can do. The deinking agent according to the present invention does not have to consist of a single component, and may be a mixture of alkylene oxide adducts of the alkylphenol resin represented by the general formula (I).

In the alkylene oxide adduct of the alkylphenol resin represented by the general formula (I), the group represented by AO is at least one selected from oxyethylene group, oxypropylene group and oxybutylene group. Shows a mixed oxyalkylene group of an oxyalkylene group and an oxyethylene group, in the case of the latter,
The group represented by AO may be in the form of either a block copolymer or a random copolymer.

In the present invention, the alkylene oxide adduct of the alkylphenol resin represented by the general formula (I) used as the active ingredient of the deinking agent can be produced by a conventional method, and a part of the adduct is obtained. , Already known as a surfactant. For example, an alkylphenol is heated and reacted with formaldehyde in the presence of an acid catalyst to obtain an alkylphenol resin, which is dehydrated under reduced pressure in a pressure vessel, and then propylene oxide, ethylene oxide, butylene oxide, propylene oxide, etc. Can be obtained by addition reaction.

The deinking agent according to the present invention is usually used in the step of disintegrating waste paper with an alkali. The amount used is sufficient in the range of 0.2 to 1.0% by weight with respect to the raw waste paper,
However, it is not limited to this. The deinking agent according to the present invention has an important advantage in that it is a one-part type, but if necessary, a conventionally known deinking agent, for example, higher fatty acid, higher alcohol, You may use together anionic surfactant and nonionic surfactant, such as higher alcohol sulfuric acid ester, higher alcohol-ethylene oxide adduct sulfuric acid ester, alkylbenzene sulfonate, alkylphenol, etc.

[0018]

The deinking agent for recycling waste paper according to the present invention contains an alkylene oxide adduct of the alkylphenol resin represented by the general formula (I) as an active ingredient. By recycling waste paper by the floatation method, it is possible to obtain high-quality recycled pulp fibers having a high whiteness, a small number of residual inks, and a high L value. Moreover, the deinking agent for recycling waste paper according to the present invention is one-component, easy to handle, and can reduce energy consumption during deinking by the floatation method. And can be done economically.

[0019]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

EXAMPLE Newspaper waste paper (offset / letter ratio 6/4) 80% by weight and scattered 20% by weight were cut into a pulp dissociator (JIS P-
8209), and sodium hydroxide 1.5%, No. 3 sodium silicate 3.5%, hydrogen peroxide solution to the weight of waste paper
Add 1.0% and 0.3% of the deinking agent shown in Table 1, and further add warm water to this so that the raw material concentration becomes 10% by weight.
The dissociation treatment was performed at 5 ° C. for 20 minutes. The pulp slurry thus obtained was diluted to a concentration of 1%, and a test floatator (manufactured by Kyokuto Shinko Co., Ltd.) at 30 ° C. for 10 minutes.
Was treated with.

In Table 1, R, n, x, y and z
Is a symbol in the general formula (I). Then, the obtained pulp slurry is treated with a standard sheet machine (JIS
P-8209) was used to prepare a sheet having a basis weight of 150 g / square meter, and the whiteness of this sheet was measured according to JIS P-
8123 and measured with a Hunter whiteness meter. The deinking amount was evaluated by measuring the number of remaining inks with an image analyzer (100 times). The L value was measured using a color difference meter based on JIS Z-8701. The results are shown in Table 1.
In the table, EO represents an oxyethylene group, PO represents an oxypropylene group, and BO represents an oxybutylene group.

Comparative Example Regenerated pulp was obtained as a sheet in the same manner as in Example except that the deinking agent shown in Table 2 was used. In Table 2, R
And n are symbols in the general formula (I), EO represents an oxyethylene group, and PO represents an oxypropylene group. In addition, the alkylene oxide adducts of the alkylphenol resins as Comparative Products 1 and 2 are the residue of the hydroxyl group of the alkylphenol resin (oxygen atom bonded to the aromatic ring).
The oxypropylene group is block-added, and then the oxyethylene group is block-added.
Table 2 shows the whiteness, the number of residual inks and the L value of the thus obtained pulp sheet.

[0023]

[Table 1]

[0024]

[Table 2]

As is clear from the results shown in Tables 1 and 2, according to the deinking agent of the present invention, an alkylphenol resin having a high molecular weight and an alkylene oxide added thereto, or an alkylphenol resin is used. It is possible to give a recycled pulp having excellent whiteness, the number of remaining inks, and an L value, as compared with those in which an ethylene oxide group is bonded to the hydroxyl group residue.

Claims (1)

[Claims] 1. A compound represented by the general formula (I): (In the formula, R represents an alkyl group having 6 to 14 carbon atoms, n represents a number of 2 or 3, PO represents an oxypropylene group, AO represents an oxyethylene group, or an oxypropylene group and an oxybutylene group. An alkylphenol represented by a mixed oxyalkylene group of at least one selected oxyalkylene group and an oxyethylene group, x is 1 to 20, y is 1 to 50, and z is a number of 1 to 50). A deinking agent for recycling used paper, which comprises an alkylene oxide adduct of a resin as an active ingredient.