JPH0647793B2 - Deinking aid for recycled waste paper - Google Patents

Description

The present invention relates to a deinking aid for recycling used paper. For more details,
Highly white and dust-proof (ink particle size 100-400) for deinking of imitation waste paper, colored waste paper, flyer waste paper, magazines, etc.
0 μm) and a deinking aid for recycling used paper to obtain a deinked pulp having a small number of residual inks.

[Conventional technology and problems]

Recycling of imitation waste paper, colored upper waste paper, flyer waste paper, magazines, etc. has been done for a long time, but especially recently, effective use of waste paper has become more important due to lack of pulp resources and soaring prices, Furthermore, the use of deinked pulp has expanded to advanced applications. On the other hand, recently used paper is becoming more and more difficult in view of changes in printing technology, printing methods, changes in printing ink components, and the use of used paper that has not been collected and used in the past. Improvements have been made to the device to promote black ink. Chemicals that have been used in the past to separate and remove ink and other impurities from waste paper include alkaline agents such as sodium hydroxide, sodium silicate, sodium carbonate, sodium phosphate, hydrogen peroxide, hyposulfite, hypophosphite, etc. Anion activity such as alkylbenzene sulfonate, higher alcohol sulfate ester salt, α-olefin sulfonate, dialkylsulfosuccinate as deinking agent together with bleaching agent such as chlorate, sequestering agent such as EDTA and DTPA Nonionic activators such as agents, higher alcohols, EO (ethylene oxide) adducts of alkylphenols and fatty acids, EO.PO (propylene oxide) adducts, and alkanol amides have been used alone or in combination of two or more.

However, it is difficult to completely separate and separate the ink from the waste paper and to remove the free ink in the flotation process and the water washing process. Especially, the removal of dust, that is, the ink with a relatively large particle size (100 to 4000 μm) is becoming a problem. is there. In particular, in the case of coated paper, high-quality paper, etc., the surface of the cellulose aggregate is coated to give the paper the necessary properties. The necessary characteristics here include printability, gloss, surface strength, and the like. For example, in order to produce better printing, it is necessary to coat the voids between the fibers of the paper with a coating to reduce the non-adhered points of the ink and obtain a beautiful and sharp printing effect. As can be seen from the viewpoint of this printing effect, the coating of the paper surface is a general surface modification method.

The coating mixture contains clay, kaolin, calcium carbonate, inorganic pigments such as titanium dioxide as a main component,
Color pigments (Ultramarine, Chrome yellow, Rake,
Dye, powder metal), adhesive (starch, casein, soy protein, latex, acrylic resin, PVA, etc.), protein solubilizer (ammonia, sodium carbonate, sodium hydroxide,
Boric acid), additives (antifoaming agent, viscosity modifier), water resistance agent (urea resin, melamine-formaldehyde resin, hexamethylenetetramine resin, glyoxal, latex, formaldehyde, sulphate), finishing agents (waxes, Soaps), separating agents (condensed phosphate, etc.), etc., and the mixing ratio differs depending on the required characteristics and operability. Ink is printed on the dry surface of the coating mixture.

When deinking imitation waste paper, colored waste paper, flyer waste paper, magazines, etc., it is presumed that the coating layer on the surface of which ink is not decomposed by a conventionally known deinking agent, causing dust. Up to now, there has been no effective means to prevent the dust, that is, to remove the ink (400 to 4000 μm) having a relatively large particle size.

[Means for solving problems]

As a result of intensive studies to improve the above problems, the inventors of the present invention have used a conventional deinking agent in combination with the deinking auxiliary agent for recycling used paper of the present invention to obtain high whiteness and dust ( The inventors have found that deinked pulp having an ink particle diameter of 100 to 4000 μm) and a small number of remaining inks can be obtained, and completed the present invention.

That is, the present invention is represented by the general formula R-SH (wherein, R is a linear or branched alkyl group having 8 to 24 carbon atoms, or an aryl group or an arylalkyl group which may have an alkyl substituent. ) Is used as a chain transfer agent, and a (co) polymer obtained by (co) polymerizing one or more selected from the group consisting of (b) to (d) below: It is intended to provide a deinking aid for recycling used paper, which contains those salts as essential components.

(b) Unsaturated monocarboxylic acid monomers and their esterified or amidated products.

(c) α, β-unsaturated dicarboxylic acid monomers, and their esterified or amidated products.

(d) α, β-ethylenically unsaturated monomers other than the above (b) and (c).

Examples of the organic thiol compound as the component (a) of the present invention include n-
Octyl mercaptan, t-octyl mercaptan, n
-Dodecyl mercaptan, t-dodecyl mercaptan,
A linear or branched chain represented by n-tetradecyl mercaptan, n-stearyl mercaptan, etc., having 8 to 24 carbon atoms.
Alkyl mercaptan having an alkyl group of benzyl, benzyl mercaptan, butyl benzyl mercaptan, n
-Octylbenzyl mercaptan, t-dodecylbenzyl mercaptan and the like, and aromatic mercaptans which may have an alkyl group as a substituent can be mentioned. The number of carbon atoms in the alkyl or aryl group of the organic thiol compound is 8
If the amount is less than 40%, the adsorptivity of the obtained copolymer to the ink will decrease, and if the number of carbons exceeds 24, the adsorption of the obtained copolymer to the ink will be very strong, and the cohesion of the inks will occur. It causes an action, resulting in a large ink particle size.

The unsaturated morecarboxylic acid monomer as the component (b), and its esterified product or amidated product are acrylic acid, methacrylic acid, or their esterified products such as methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid. Octyl, lauryl acrylate, octadecyl acrylate, methyl methacrylate, ethyl methacrylate,
Examples thereof include butyl methacrylate, octyl methacrylate, lauryl methacrylate, octadecyl methacrylate, or amidated products such as acrylamide and methacrylamide. Among them, acrylic acid and methacrylic acid are particularly preferable.

Examples of the α, β-unsaturated carboxylic acid monomer as the component (c), and their esterified or amidated products include maleic anhydride, maleic acid, fumaric acid, itaconic acid, and maleic acid monoesters which are esterified products thereof. Butyl ester,
Examples thereof include maleic acid monooctyl ester, maleic acid dibutyl ester, maleic acid dilauryl ester, itaconic acid butyl ester, and amide compounds thereof such as maleic acid monooctylamide and maleic acid monolaurylamide. Among them, maleic anhydride and maleic acid are particularly preferable.

(d) component (b), other than (c), α, β-ethylenically unsaturated monomers as vinyl acetate, vinyl chloride, or cyclopentene, dicyclopentadiene, butylene, pentene, diisobutylene, octene, Olefins such as decene, or aromatic ring-containing vinyl monomers such as styrene, or sulfonic acid group-containing vinyl monomers such as vinyl sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, or acrylonitrile,
Methacrylonitrile, dimethylaminoethylmethacrylate, diethylaminoethylmethacrylate, acryltriethylammonium chloride, methacryltriethylammonium chloride and the like can be mentioned.

The (co) polymer of the present invention or a salt thereof uses the compound (a) which is an essential component as a chain transfer agent, and peroxidizes at least one selected from the components (b), (c) and (d). Compound or an azo catalyst in the presence of an organic solvent such as isopropyl alcohol, methanol, ethanol or a mixed solvent thereof with water by a known method, and if necessary, they are further subjected to a salt-forming reaction to obtain. To be

In the (co) polymer of the present invention or a salt thereof, the molar ratio of the essential (a) component to the other monomers of the (b), (c) and (d) components is (a) component compound / One or more of component compounds (b), (c) and (d) = 1/3 to 1/100 are preferable, and 1 is more preferable.
/ 5 to 1/50. The average molecular weight is adjusted by the amount of the component (a) or other chain transfer agent and the like, but it is preferably 500 or more, more preferably 1000 to 10000. The molecular weight is measured by gel permeation chromatography (GPC).

Examples of the salt of the (co) polymer of the present invention include alkali metal salts such as sodium and potassium, alkaline earth metal salts such as magnesium and calcium, and ammonium salts.

The deinking aid for recycling used paper of the present invention is used in combination with a conventionally known deinking agent. The known deinking agent may be either an anionic surfactant or a nonionic surfactant, or may be a mixed system thereof. As the anionic surfactant, alkylbenzene sulfonate, alkyl sulfate, polyoxyalkylene alkyl (or alkylaryl) sulfate, alkane sulfonate, α-olefin sulfonate, dialkyl sulfosuccinate, higher fatty acid salt, Examples thereof include alkyl ether carboxylic acid salts. Nonionic surfactants include higher alcohols, EO (ethylene oxide) adducts of alkylphenols and fatty acids, EO / PO (propylene oxide) adducts,
Examples include higher fatty acid amides and amine oxides.
In particular, nonionic surfactants are the mainstream as deinking agents for imitation waste paper, colored waste paper, flyer waste paper, magazines and the like.

The amount of the deinking aid for recycling used paper of the present invention is preferably 1/10 to 10/1, and more preferably 1/3 to 3/1 by weight ratio with respect to the known deinking agent used in combination. The addition amount of the deinking aid for recycling used paper of the present invention is 0.
The range of 05 to 2.0% by weight is preferable.

The time for adding the deinking aid for recycling used paper of the present invention is preferably a used paper disintegration step and a step corresponding thereto, and it must be a step to which a certain amount of shear energy is applied. Further, the deinking aid of the present invention is usually used together with the deinking agent, but the addition steps are not necessarily simultaneous.

Although the mechanism of the deinking auxiliary agent for recycling used paper of the present invention is not always clear, it is introduced in the flotation process in spite of further dispersing and refining the giant ink particles separated from cellulose in the waste paper disintegration process. It is presumed that the heteroaggregation to the air bubbles is not hindered, and the ink re-adhesion preventing property to the pulp is enhanced. In addition, in the water washing step, it is presumed that the ink particle size is controlled so that deinking with a valveless filter, an extractor or the like is good. These are attributed to the remarkably excellent ink dispersive power (meaning dispersive power that does not inhibit heterocoagulation between air bubbles and ink particles) and protective colloid ability of the deinking auxiliary agent for recycling used paper of the present invention. It is presumed that, when deinking imitation waste paper, colored waste paper, flyer waste paper, magazines, etc., when the deinking agent and the deinking aid of the present invention coexist, extremely dust (ink particle diameter 100 to 4000 μm) and It is presumed that deinked pulp with a small number of residual ink can be obtained.

〔Example〕

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

In addition, the deinking aid for recycling used paper of the present invention used in Examples is shown in Table 1.
Shown in.

Example 1 After cutting the recovered colored fine paper in the market into 2 × 5 cm, a certain amount of the recovered waste paper was put into a table disintegrator, and water and sodium hydroxide (relative to raw material) 1.0%, sodium silicate (relative to raw material) 2.5 were put therein. %, 30%
After adding hydrogen peroxide (vs. raw material) 5.0% and deinking agent (vs. raw material) 0.3%, and further adding deinking auxiliary agent (vs. raw material) 0.3% for recycled waste paper, pulp concentration 5%, temperature of 50 ° C Disaggregated for 20 minutes under. Then, after aging for 60 minutes at 50 ° C, water was added to dilute the pulp concentration to 1%, and a flotation treatment was performed at 30 ° C for 10 minutes. Dehydrate the pulp slurry after flotation to 6% concentration, add water to dilute it to 1% concentration,
Pulp sheets were produced on a TAPPI standard sheet machine. The whiteness of the obtained pulp sheet was measured with a colorimetric color difference meter, and the dust (number of remaining inks, ink particle size 100 μm or more) was measured with an image analyzer (× 4 times).
The results are shown in Table 2.

Example 2 After collecting the recovered colored paper in the market into 2 × 5 cm, a certain amount of the recovered waste paper was put into a table disintegrator, and water and sodium hydroxide (against raw material) 1.0%, sodium silicate (against raw material) 1.0 %, 30%
After adding hydrogen peroxide (against raw material) 2.0%, deinking agent (against raw material) 0.3%, and further adding deinking aid for recycled waste paper (against raw material) 0.2%, pulp concentration 5%, temperature of 55 ° C Disaggregated under for 15 minutes. Then, it was dehydrated with an 80 mesh wire so that the pulp concentration became 18%, and aged at 60 ° C for 90 minutes. Then, the pulp concentration was diluted to 4%, and disintegrated for 5 minutes with a table disintegrator, and water was further added to dilute the pulp concentration to 1%.
A washing step of dehydrating the pulp concentration to 10% with an 80 mesh wire was repeated twice, and then a pulp slurry having a pulp concentration of 1% was prepared using a TAPPI standard sheet machine. The whiteness of the obtained pulp sheet was measured with a colorimetric color difference meter, and the dust (number of remaining inks, ink particle size 100 μm or more) was measured with an image analyzer (× 4 times). The results are shown in Table 3.

Claims (1)

[Claims] 1. A general formula R-SH (wherein, R is a linear or branched alkyl group having 8 to 24 carbon atoms, or an aryl group or an arylalkyl group which may have an alkyl substituent.) (Co) polymer obtained by (co) polymerizing one or more kinds selected from the group consisting of the following (b) to (d) using an organic thiol compound (a component) represented by A deinking aid for the recycling of used paper, which contains as an essential component the salt of. (b) Unsaturated monocarboxylic acid monomers and their esterified or amidated products. (c) α, β-unsaturated dicarboxylic acid monomers, and their esterified or amidated products. (d) α, β-ethylenically unsaturated monomers other than the above (b) and (c).