JP2810477B2 - Deinking agent for recycled paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a deinking agent used for recycling used paper such as newspapers and magazines. More specifically, the present invention relates to a deinking agent capable of obtaining a deinked pulp having high whiteness and a small number of remaining inks when performing deinking treatment on newspapers, magazines and the like by a flotation method and a flotation / washing combination system.

[Problems to be solved by conventional technology and invention]

Recycling of newspapers, magazines, etc. has been practiced for a long time, but in recent years, the effective use of pulp resources has become increasingly important from the viewpoint of shortage of pulp resources and soaring prices, as well as measures against garbage and protection of forest resources. It is taking on. The development of advanced technology for the use of deinked pulp has been spurred to meet the growing needs.

On the other hand, recently used paper has become more severe in terms of deinking due to changes in printing techniques, printing methods, and printing ink components.

Therefore, in order to further promote deinking, improvements have been made to the apparatus. For example, high-concentration aging treatment by tower equipment, introduction of disposer and kneader to further promote ink peeling by physical force,
Furthermore, installation of a high-concentration pulverizing pulper and the like can be mentioned. In addition, the introduction of a high-bubble type floatator has also become active in floatators.

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 hypochlorite. Bleaching agents such as salt, EDTA, DT
Along with sequestering agents such as PA, as deinking agents, alkyl benzene sulfonates, higher alcohol sulfates, α-olefin sulfonates, anionic activators such as dialkyl sulfosuccinates, higher alcohols, alkylphenols and fatty acids. Ethylene oxide adduct,
Nonionic activators such as alkanolamides have been used alone or in combination of two or more. However, these deinking agents have a high foaming property in the flotation process, but have a low ink collecting ability, and have a low detergency in the cleaning method, so that only low-quality deinking pulses can be obtained. Furthermore, even if pulp with high whiteness is obtained, there is dullness, so that the use of deinking pulses is restricted (reduction in the amount of paperboard used below and below, reduction in the amount of blending in newspapers, etc.) and dullness are eliminated. As a result, the amount of bleach used had to be increased.

[Means for solving the problem]

The present inventors have developed a deinking agent for wastepaper recycling that exhibits excellent ink collecting ability in the flotation treatment process and can obtain deinked pulp having high whiteness, a low number of residual inks, and a small number of unstripped inks. As a result of intensive research to develop,
The present invention has been completed.

That is, the present invention relates to a compound containing an OH group represented by the following (A), (B), (C) or (D), and 1.2 to 4 carboxyl groups per OH group in the compound. An object of the present invention is to provide a deinking agent for recycling used paper, which contains, as an active ingredient, a reaction product with a polycarboxylic acid or an anhydride thereof in an amount to give a group.

(A); an ethylene oxide and a propylene oxide were added to an alkyl or alkenyl alcohol having 3 to 24 carbon atoms at a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in an average of 2 to 50 moles in total. Compound (B); a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in phenol or aryl alcohol having one or two alkyl groups or alkenyl groups having 3 to 24 carbon atoms. (C) a bis (hydroxyphenyl or cyclohexyl) alkane having an alkyl or alkenyl group having 3 to 24 carbon atoms (the number of carbon atoms in the alkane chain is an odd number) To ethylene oxide / propylene oxide Compound (D) obtained by adding an average of 2 to 50 moles of OH groups per each such that pyrene oxide has a ratio of 1 to 4 (molar ratio); (D) an alkyl or alkenyl group having 3 to 24 carbon atoms Ethylene oxide and propylene oxide are added to a phenol formaldehyde condensate having one or two phenol formaldehydes so that the ratio of ethylene oxide / propylene oxide is 1 to 4 (molar ratio). The functions required of the deinking agent are: the ability to lower the interfacial tension between cellulose and the ink; the ability to prevent redeposition of the ink peeled from the cellulose; the high adsorption of the ink to the air bubbles; and the proper foaming properties. Can be mentioned. A deinking agent must have these four functions in a well-balanced manner.

In the present invention, ethylene oxide and propylene oxide to be added to the compound containing an OH group used for obtaining the compound of (A), (B), (C) or (D) may be either block or random addition, Preferably, it is a random addition. The molar ratio between ethylene oxide and propylene oxide is preferably in the range of ethylene oxide / propylene oxide = 1 to 4, and more preferably in the range of 1 to 3. When the molar ratio is less than 1, the dispersion of the ink released from the cellulose is large, and the ability to form a foam layer on the liquid level of the flotator is weak, so that the number of foam layers holding the ink is reduced. As a result, the whiteness decreases. Conversely, when the molar ratio is greater than 4, the air bubble adsorbing property in the flotator is small, and as a result, the hue of the foam layer also has low ink collecting ability and becomes whitish. Further, since the foam layer has a strong ability to form a foam layer on the liquid level of the flotator, the amount of froth foam is large.
In addition, phenomena that are extremely problematic for operability, such as poor foaming properties in the frost pit, frequently occur.

The number of moles of ethylene oxide and propylene oxide added is preferably 2 to 50 moles on average per 1 active hydrogen atom. Preferably it is 10 to 35 mol. When the number of added moles is smaller than 2, the whiteness decreases because the ink releasability from cellulose and the ability to collect ink released from cellulose are small. Also, if the added mole number is larger than 50, the foaming layer forming ability on the flotator liquid surface is weakened, so that the foam layer that has collected the ink is not removed out of the system, and as a result, the whiteness decreases. Has disadvantages.

A compound of the above (A), (B), (C) or (D);
A reaction product obtained by reacting an amount of a polyvalent carboxylic acid or an anhydride thereof that gives 1.2 to 4 carboxyl groups to one OH group in the compound is a deinking agent for recycling used paper of the present invention. Of the active ingredient.

In the reaction of the compound (A), (B), (C) or (D) with the polyvalent carboxylic acid, the charging ratio of the two is as follows: (I) In the case of a divalent carboxylic acid or its anhydride, (A), (B) ), (C) or (D) residual OH of each compound
Almost 1 mol of carboxylic acid or its anhydride per 1 group.

(II) In the case of trivalent carboxylic acid or its anhydride (A), (B), (C) or (D) Residual OH of each compound
0.5 to 1 mol of carboxylic acid or its anhydride per one group.

(III) In the case of tetravalent carboxylic acid or its anhydride (A), (B), (C) or (D) Residual OH of each compound
0.3 to 1 mol of carboxylic acid or its anhydride per one group.

(IV) In the case of hexavalent carboxylic acid or its anhydride (A), (B), (C) or (D) Residual OH of each compound
0.2 to 0.6 mol of carboxylic acid or its anhydride per one group.

The above (I) to (IV) are preferred. When (A), (B), (C), or (D) is extremely large in this charging ratio, the whiteness is reduced because the ink collecting performance of the flotator is reduced. In the opposite case, that is, when the amount of the polycarboxylic acid is extremely large, the ink releasability from cellulose becomes small, so that the amount of unreleased ink increases, and only deinked pulp having a poor appearance can be obtained.

Polycarboxylic acids include oxalic acid, succinic acid, maleic acid, glutaric acid, adipic acid, phthalic acid, citric acid, trimellitic acid, maleated oleic acid, butanetetracarboxylic acid, pyromellitic acid, and tetradecanehexacarboxylic acid When these polycarboxylic acids form an acid anhydride, it is preferable to use the acid anhydride. Examples of the acid anhydride include maleic anhydride, succinic anhydride, glutaric anhydride, phthalic anhydride, trimellitic anhydride, and pyromellitic anhydride.

The method for producing the deinking agent for recycling waste paper of the present invention is not particularly limited, and the compound having an OH group as described in (A), (B), (C) or (D) and a polyvalent carboxylic acid Alternatively, it can be produced by mixing and reacting with an acid anhydride thereof. For example, JP-B-46-41887, JP-B-60-33098, and U.S. Pat.
U.S. Patent No. 2028091 (1936), The Chemical Society of Japan, No. 2 (1976), pp. 261-265, Hiroshi Horiguchi, "Synthetic Surfactants" Sankyo Publishing Co., Ltd., pp. 203-204, Oil Chemistry Vol. 26, No. 5, 1977
The synthesis methods described on pages 283 to 286 correspond thereto.

The deinking agent for recycling waste paper of the present invention may be added to any of the waste paper disintegration step, the kneader treatment step, the aging tower step and the flotation treatment or to each step, but the most effective is the case where it is added to the waste paper disintegration step. Is high. The amount of addition is preferably 0.05 to 1.0% by weight based on the raw waste paper.

〔Example〕

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

Production Example 1 Polyoxyethylene / polyoxypropylene (hereinafter referred to as POE / POP) stearyl ether (EO = 16 mol, PO = 8 mol, block polymerization,
EO; ethylene oxide, PO; propylene oxide; means the number of moles added. The same applies hereinafter. ), 35.2 g of succinic anhydride, and 3.0 g of sodium acetate as a catalyst, and reacted under a nitrogen atmosphere at a reaction temperature of 100 ° C. and a stirring speed of 500 rpm.

Production Example 2 543.9 g of random polymerization of 10 mol of EO and 5 mol of PO to nonylphenol and 56.1 g of maleic anhydride were charged into a 14-necked flask, and reacted at a reaction temperature of 100 ° C. and a stirring speed of 500 rpm under a nitrogen atmosphere. I let it.

Preparation Example 3 2,4-bis (4'-hydroxyphenyl) propane (EC = 18 mol, PO = 6 mol,
518.9 g of random polymerization), 78.1 g of maleic anhydride and 3.0 g of sodium hydroxide were charged and reacted at a reaction temperature of 110 ° C. and a stirring temperature of 500 rpm under a nitrogen atmosphere.

Example 1 A used newspaper collected in the city was shredded to 2 x 5 cm, and a certain amount was placed in a tabletop disintegrator, in which water and caustic soda (based on raw material) were 1.0% (weight basis, the same applies hereinafter), sodium silicate 3.0% (based on raw material), 30% hydrogen peroxide water (based on raw material) 3.0%, Table-1
After adding 0.4% of various deinking agents (based on raw materials) shown in (1), the pulp concentration was 5%, the mixture was separated at 55 ° C for 20 minutes, and then ripened at 50 ° C for 60 minutes. Then, water was added to dilute the pulp concentration to 1.0%, and CaC
l ₂ (based on raw material) was added, and flotation treatment was performed at 30 ° C. for 10 minutes. The pulp slurry after flotation was concentrated to a 6% concentration, and then diluted to 1% concentration by adding water, and a pulp sheet was prepared using a TAPPI sheet machine.
The whiteness of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured with an image analyzer (× 100). Further, the height of the foam layer on the flotator liquid surface (at 3 minutes) was also measured.

 Table 2 shows the results.

Example 2 A used newspaper collected in the market was cut into 2 x 5 cm pieces, and a certain amount was put into a table disintegrator, in which water and caustic soda (based on raw material) were 1.0%, and sodium silicate 3 (based on raw material) was 0.5. %, And 0.4% of various deinking agents (based on raw materials) shown in Table 3 were added. After decomposing at a pulp concentration of 5% at 45 ° C, the pulp was dehydrated to a pulp concentration of 18%. Add 1.5% (based on raw material), 2.5% sodium silicate 3 (based on raw material), and 3.0% 30% aqueous hydrogen peroxide (based on raw material), mix, and ripen at 55 ° C for 90 minutes at a pulp concentration of 15%. Processing was performed. Then pulp concentration 4%
Water and dilute it with a desktop disintegrator for 5 minutes, add water to dilute the pulp concentration to 1.0%, and add CaCl ₂
(To raw material) 1.0% was added and flotation treatment was performed at 30 ° C. for 10 minutes. After concentration of the pulp slurry after flotation to a 6% concentration, water was added to dilute it to a 1% concentration,
Pulp sheets were prepared using a TAPPI sheet machine. The whiteness of the obtained pulp sheet was measured with a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured with an image analyzer (× 100). Further, the height of the foam layer on the flotator liquid surface (at 3 minutes) was also measured.

 Table 4 shows the results.

Example 3 A city-recovered magazine was shredded to 2 × 5 cm, and a certain amount was put into a low-concentration pulper, in which water and caustic soda (based on raw material) were 0.5%, and sodium silicate 3 (based on raw material) was 1.5%. , 30% hydrogen peroxide (relative to the raw material), 1.0%, and 0.05% of the deinking agent (relative to the raw material) shown in Table 5 were added. Then, water was added to the mixture, and the pulp concentration was 4.0
% And then add more water to reduce the pulp consistency to 1.0%
And This was subjected to a flotation treatment at 30 ° C. for 10 minutes. The pulp slurry after the flotation was concentrated to a 6% concentration and then diluted with water to 1% concentration to prepare a pulp sheet with a tappy sheet machine.

The white color of the obtained pulp sheet was measured by a colorimeter (diffuse reflection type), and the total number of remaining inks and the number of unstripped inks were measured by an image analyzer (× 100). In addition, the height of the foam layer on the flotator liquid surface (after 3 minutes) was also measured.

 The results are shown in Table-6.

Claims (6)

(57) [Claims] An OH group-containing compound represented by the following (A), (B), (C) or (D):
A deinking agent for recycling used paper, comprising as an active ingredient a reaction product of a polycarboxylic acid or an anhydride thereof in an amount giving 1.2 to 4 carboxyl groups per unit. (A); an ethylene oxide and a propylene oxide were added to an alkyl or alkenyl alcohol having 3 to 24 carbon atoms at a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in an average of 2 to 50 moles in total. Compound (B); a ratio of ethylene oxide / propylene oxide = 1 to 4 (molar ratio) in phenol or aryl alcohol having one or two alkyl groups or alkenyl groups having 3 to 24 carbon atoms. (C) a bis (hydroxyphenyl or cyclohexyl) alkane having an alkyl or alkenyl group having 3 to 24 carbon atoms (the number of carbon atoms in the alkane chain is an odd number) To ethylene oxide / propylene oxide Compound (D) obtained by adding an average of 2 to 50 moles per OH group so that the ratio of pyrene oxides is 1 to 4 (molar ratio); (D) an alkyl or alkenyl group having 3 to 24 carbon atoms. Ethylene oxide and propylene oxide were added to the phenol formaldehyde condensate having one or two phenol formaldehydes so that the ratio of ethylene oxide / propylene oxide was 1 to 4 (molar ratio). Compound 2. The method of claim 1, wherein the polycarboxylic acid or anhydride thereof is oxalic acid, succinic acid, maleic acid, glutanic acid, adipic acid,
Phthalic acid, citric acid, trimellitic acid, maleated oleic acid, butanetetracarboxylic acid, pyromellitic acid, tetradecanehexacarboxylic acid, maleic anhydride, succinic anhydride, glutaric anhydride, phthalic anhydride, trimellitic anhydride and The deinking agent according to claim 1, which is selected from the group consisting of pyromellitic anhydride. 3. Compound (A), (B), (C) or (D)
2. The deinking agent according to claim 1, wherein approximately 1 mol of a divalent carboxylic acid or an anhydride thereof is used per one residual OH group. 4. A compound (A), (B), (C) or (D)
The deinking agent for recycling waste paper according to claim 1, wherein 0.5 to 1 mol of a trivalent carboxylic acid or an anhydride thereof is used per 1 residual OH group of the above. 5. Compound (A), (B), (C) or (D)
2. A deinking agent for recycling waste paper according to claim 1, wherein 0.3 to 1 mol of a tetravalent carboxylic acid or an anhydride thereof is used per 1 residual OH group. 6. A compound (A), (B), (C) or (D)
The deinking agent for recycling waste paper according to claim 1, wherein a hexavalent carboxylic acid or an anhydride thereof is used in an amount of 0.2 to 0.6 mol per residual OH group.