EP0445160A1

EP0445160A1 - De-inking of old papers

Info

Publication number: EP0445160A1
Application number: EP89912961A
Authority: EP
Inventors: Herbert Fischer; Klaus Hornfeck; Ludwig Schieferstein
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1988-11-23
Filing date: 1989-11-14
Publication date: 1991-09-11
Also published as: EP0373375A3; YU220089A; RU1833445C; EP0373375B1; FI912248A0; DE3839479A1; FI95605B; CA2003406A1; EP0373375A2; ATE80424T1; JPH04502038A; WO1990005805A2; FI95605C; WO1990005805A3; ES2045352T3; TR24045A; DE58902253D1

Abstract

Process for de-inking old papers in the presence of at least partly water-soluble polymers and/or copolymers with mean molecular weights between 2000 and 500 000 obtained by polymerization or by copolymerization of monomers containing amino groups with unsaturated acid derivatives.

Description

"Deinking of waste paper"

The invention relates to a process for deinking waste paper and the use of at least partially water-soluble polymers and / or copolymers with number average molecular weights between 2000 and 500000, produced by polymerization or copolymerization of unsaturated acid derivative monomers containing amino groups for deinking of waste paper.

For the production of, for example, newspaper printing and hygiene papers, waste paper is used in large quantities today. For these types of paper, brightness and color mean certain quality features. To achieve this, the printing inks must be removed from the printed waste paper. This is usually done using deinking processes, which essentially take place in two steps:

1. opening the waste paper, d. H. Defibrating in water with simultaneous action of the chemicals and. Required for the detachment of the printing ink particles

2. Elimination * of the detached ink particles from the fiber suspension.

REPLACEMENT LEAF The second process step can be carried out by washing or flotation (Ulimanns Encyclopedia of Industrial Chemistry, 4th edition, volume 17, pages 570-571 (1979)). In flotation, in which the different wettability of printing inks and paper fibers is used, air is pressed or sucked through the fiber suspensions. Small air bubbles combine with the ink particles and form a foam on the surface of the water, which is removed with fabric strings.

The deinking of waste paper is usually carried out at alkaline pH values in the presence of alkali hydroxides, alkali silicates, oxidative bleaches and surface-active substances at temperatures between 30 and 50 ° C. Soaps and / or fatty alcohol polyglycol ethers are frequently used as surface-active substances which cause the printing inks to separate and separate (Ullmanns Encyclopedia of Industrial Chemistry, 4th edition, volume 17, pages 571-572 (1979)).

Copolymers of acrylamide and dimethyldiallylammonium chloride, the molecular weights of which are preferably between 2,000,000 and 10,000,000, are known from European patent EP 172 684 and can be used for deinking cellulosic material. However, the papers treated in this way have very poor levels of whiteness.

The classic printing ink systems, for example based on nitrocellulose, maleate resins and / or shellac, the esters and / or ketones, for example ethyl acetate. and / or methyl ethyl ketone, or alcohols as solvents, have been increasingly replaced in recent years by water-thinnable printing inks for environmental reasons. Another reason for the increasing use of water-borne printing inks is in

REPLACEMENT LEAF the incombustibility of water, as a result of which the installation of complex protective devices necessary when using solvent-based printing inks is unnecessary in the printing works. Most water-thinnable printing inks contain anionic polymers as binders, for example polymers containing carboxyl groups, which neutralize with bases make the printing inks water-thinnable. Water-thinnable printing inks, however, have the decisive disadvantage that they can only be removed completely inadequately, if at all, using the usual surfactants contained in the deinking fleet (Wochenblatt für Papierfabrikation .13, 537-538 (1988)). The result of this is that to date the waste paper that is being produced in ever larger quantities and that has been printed with water-thinnable printing inks has not been recycled and is therefore not available as a waste paper raw material for newsprint and hygiene papers.

The object of the invention was therefore to develop a deinking process with which it is possible to deink waste paper. In particular, such a deinking process should make it possible to deink waste paper which contains waste paper components printed with water-dilutable printing inks.

Surprisingly, it has been found that printing inks and in particular water-thinnable printing inks in wash deinking or flotation deinking processes in the presence of at least partially water-soluble polymers and / or copolymers with number average molecular weights between 2000 and 500,000, produced by polymerization or copolymerization of amino-containing, unsaturated acid derivative monomers can be removed.

The invention accordingly relates to a method for deinking waste paper, which is characterized in that Waste paper in the presence of at least partially water-soluble polymers and / or copolymers with number-average molecular weights between 2000 and 500000, produced by polymerization of

A. amino group-containing monomers of the general formula I

R- - CH = CR2 -

in which R ¹ and R - *** are each hydrogen or methyl, R ³ and R ^{4 are} each hydrogen or a Cι_4-alkyl radical or a Piperazin, piperidine or morpholine radical, R5 is a straight or branched chain alkyl radical with 1 to 22 represents C atoms, with the proviso that the counterion to the ammonium function is a halogen, sulfate, phosphate, borate or organic acid anion, or R5 is a pair of electrons, Z is 0 or NH and n is a number between 2 and 5,

or by copolymerization of A. with

Bl. Monomeric, unsaturated acids of the general formula II

0

II

R ⁵ - CH = CR ⁵ - C - 0H

in which R5 and R ⁶ each represent a hydrogen atom or a methyl group, and / or

B2. monomeric, unsaturated carboxylic acid esters of the general formula III

REPLACEMENT LEAF R ⁷ - CH = CR ⁸ - C - 0 - CCIT ^» .H 2, ^~ ~ 0) ^J p R ^"

in which the radicals R ⁷ and each represent a hydrogen atom or a methyl group and 9 represent a straight-chain or branched-chain alkyl group having 1 to 22 C atoms and m represents numbers between 2 and 4 and p is a number between 0 and 18, with the proviso that if p = 0 the content of unsaturated carboxylic acid esters in the copolymer does not exceed 30% by weight and / or

B3. Acrylamides and / or Methacryla iden that are attached to the Amidstick. Substance atoms can be substituted by straight and / or branched chain alkyl radicals having 1 to 22 carbon atoms, and / or

B4. N-vinyl pyrrolidone,

are opened and then the printing ink particles are removed from the fiber suspensions in a manner known per se by flotation or washing out.

Another object of the invention is the use of these polymers and / or copolymers with number average molecular weights between 2000 and 500000 for deinking printed waste paper.

Preferably at least partially water-soluble polymers and / or copolymers with number average molecular weights between 5,000 and 200,000, particularly preferably those with number average molecular weights between 10,000 and 100,000 are used.

ERS "At least partially water-soluble" means that the polymers and / or copolymers are more than 0.01% by weight clear or cloudy soluble in water at the application pH.

Particularly suitable amino group-containing monomers of the general formula I are those in which the radicals R- hydrogen, R-- hydrogen or methyl, R ³ and R ^{4 are} each methyl or ethyl, R ^{5 is} a pair of electrons or R ^{5 is} a C 4 alkyl group with the that the counterion to the ammonium function is a halogen anion is provided and Z represents 0 or NH and n is a number between 2 and 5, the pitch bei¬ dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, Dimethylaminoneopentyl- ^"acrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate and / or methacrylamidopropyltrimethylammonium The monomeric, unsaturated acids of the general formula II used are preferably acrylic acid and / or methacrylic acid Monomers, unsaturated carboxylic acid esters of the general formula III in which the radical R 1 preferably contains a straight-chain or branched-chain alkyl group 1 to 8 carbon atoms are, for example, ethyl acry lat, methyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate and / or butyl ^• 3 moles of ethylene oxide acrylate. Acrylamide, methacrylamide, N-ethyl acrylate and / or tert-butyl acrylamide are also suitable for copolymerization with monomers of the general formula I containing amino groups.

The polymerization or copolymerization of the amino group-containing monomers of the general formula I is carried out by known polymerization processes in aqueous media, which, if desired, water-miscible solvents, such as alcohols - for. B. opropsopropanol - included, carried out (Ullmanns Encyclopedia of technical chemistry, 4th edition, Volume 19, page 3-4, Verlag Chemie Weinheim, 1980). As a starter, a radical-forming substance for example potassium or ammonium peroxide sulfate, tert-butyl hydroperoxide, azobis (cyanopentanoic acid),

Azobis (isobutyronitrile) or 2,2'-

Azobis (2-amidinopropane dihydrochloride), added in small amounts. The polymerization or copolymerization of the amino group-containing monomers of the general formula I can be carried out, for example, in such a way that monomers of the general formula I containing amino groups and optionally monomers of the groups B1, B2, B3 and / or B4 simultaneously in water which contains the starter , be dropped. The polymerization temperature can vary within a wide range. Depending on the starter used, temperatures between 60 and 100 ° C can be optimal. Aqueous polymer and / or copolymer solutions with polymer contents, for example between 10 and 60 percent by weight, are obtained.

In the presence of the above A wide variety of printing inks, in particular water-dilutable printing inks, for example newspaper rotary inks, letterpress inks, offset printing inks, illustration gravure inks, flexographic and packaging inks from printed waste paper, for example newspapers, magazines, computer papers, magazines, brochures, forms, telephone books, can be polymers and / or copolymers and / or remove catalogs. The deinked waste papers obtained are characterized by very high degrees of whiteness.

The waste papers to be deinked are dissolved in a cloth dissolver in an aqueous solution, which is typically 0.5 to 1.0% by weight 100% hydrogen peroxide, 0.5 to 2.5% by weight 100% NaOH up to 4.0% by weight of water glass, 35% by weight (37 - 40 ° B§) and 0.01 to 1% by weight of active substance polymers and / or copolymers - all% by weight - data refer to air-dry waste paper - contains, opened at temperatures between 20 and 60 ° C. To good ones

REPLACEMENT LEAF 8th

To obtain deinking results, 0.01 to 1 g of active substance, polymers and / or copolymers according to the invention are used per 100 g of air-dry waste paper. After a dwell time between 60 and 120 minutes at temperatures between 20 and 60 ° C, the fiber suspensions are stirred into water, so that 0.6 to 1.6 wt .-% pulp suspensions are obtained. The flotation is then preferably carried out in a manner known per se, for example in a Denver flotation cell.

Examples

Production of polvdimethylaminoethyl methacrylate (polymer I) 170 mg of 2,2'-azobis (2-amidinopropane dihydrochloride) and 36.8 g of water were placed in a reactor with stirrer, 2 feed vessels, heating, cooling, reflux cooling and temperature measurement. 42 g of dimethylaminoethyl ethacrylate were added to one inlet vessel (inlet vessel 1), the other a solution of 330 mg of 2,2'-azobis (2-amidinopropane dihydrochloride) and 4 g of water. After heating the stock solution in the reactor with stirring to 75 ° C., both feed solutions were added in parallel within 90 minutes. After the feed had ended, the mixture was stirred at 80 ° C. for 60 minutes, then it was cooled to about 45 ° C. and neutralized with 16.7 g of a 50% strength by weight formic acid.

Characteristic data of the clear, 50% by weight aqueous solution obtained: Brookfield viscosity (measured with spindle 5 at 20 revolutions per minute, temperature = 25 ° C.): 18000 mPas

Preparation of the copolymer from 78% by weight of dimethylaminoethyl methacrylate, 7% by weight of methacrylic acid and 15% by weight of ethyl acrylate (copolymer I)

The copolymer I was prepared analogously to the preparation of polymer I, 53.5 g instead of 36.8 g of water being introduced and a mixture of 39 g of dimethylaminoethyl methacrylate, 7.5 g of ethyl acrylate and 3.5 g into the feed vessel 1 Methacrylic acid was given.

The neutralization step was dispensed with.

Characteristic data of the opaque 50% by weight aqueous solution obtained: Brookfield viscosity (measured with spindle 5 at 20 revolutions per minute, temperature = 25 ° C.): 33000 mPas

REPLACEMENTB 10

Manufacture of the copolymer from 73% by weight of dimethylaminoethyl methacrylate. 11% by weight of acrylic acid and 16% by weight of methyl methacrylate (copolymer II)

32.0 g acrylic acid

106.7 g of 30% by weight sulfuric acid and 976.0 g of water and 217.6 g of dimethylaminoethyl methacrylate and 46.2 g of methyl methacrylate

1.1 g of azobis (isobutyronitrile) and 263.0 g of isopropanol were premixed separately, then placed in a reaction vessel with stirrer, heating and reflux cooling, heated to 65 ° C. and then 30 minutes at this temperature, one hour at 70 ° C and stirred at 80 ° C for one hour.

Characteristic data of the clear 20% by weight aqueous isopropanol solution obtained: specific viscosity of a 1% by weight polymer solution in 1N NaNOß solution: 1.28

Preparation of the copolymer from 70% by weight of dimethylaminomethyl methacrylate and 30% by weight of acrylamide (copolymer III) 527 g of water and 1.6% were added to a reaction vessel with stirrer, 2 feed vessels, heating, cooling, reflux cooling and temperature measurement g Azobis (cyanopentanoic acid) submitted.

140 g of dimethylaminoethyl methacrylate, 60 g of acrylic acid and 147.4 g of 30% by weight sulfuric acid were added to one feed vessel, and 1.6 g of azobis (cyanopentanoic acid) and 40 g of water were added to the other.

After the stock solution had been heated to 75 ° C., both feed solutions were added in parallel within 90 minutes. After the end The mixture was stirred at 85 ° C. for 60 minutes. The result was a clear, 27% by weight polymer solution with a Brookfield viscosity of 740 mPas (measure at 25 ° C. and 20 revolutions per minute with spindle 2).

Examples of use

98 g lutro (= 90 g atro at 8% moisture) printed waste paper

(lutro = air dry, atro = absolutely dry) from 100% newspapers, printed with water-dilutable flexographic printing inks, was at 3.5

% By weight consistency in the laboratory pulper with aqueous solutions consisting of

2% by weight soda water glass, 37 - 40 ° B§ 1% by weight sodium hydroxide (100%) 0.7% by weight hydrogen peroxide (100% by weight) 0.4% by weight surfactant or 0 , 2 wt .-% polymer or copolymer according to the invention

whipped at 45 ° C by means of a dispersing disc (3000 revolutions per minute) and after 1 3/4 hours at 45 ° C diluted to 1% by weight by stirring the fiber suspensions in water. The fibrous suspensions were then floated at 45 ° C. in a Denver flotation cell at 1,900 revolutions per minute within 15 minutes.

The deinking results of the deinked waste paper obtained in the presence of different polymers and copolymers and in the presence of surfactants are summarized in Table 1. The deinkability index (DEM) was calculated from the reflection factors R457n (whiteness) of the printed (BS), deinked (DS) and unprinted (US) paper stock using the following formula:

REPLACEMENT LEAF 12

Whiteness (DS) - Whiteness (BS)

DEM (%) = - x 100

Whiteness (US) - Whiteness (BS) (0% means no ink removal, 100% means quantitative ink removal).

REPLACEMENT LEAF

-) OlinorR 4010, Henkel KGaA

² ) copolymer of 70% by weight dimethylaminoethyl acrylate and 30

% By weight of acrylamide - number average molecular weight:> 500000; Manufacturer: Henkel KGaA

Claims

14 claims

1. A process for deinking waste paper, characterized in that waste paper in the presence of at least partially water-soluble polymers and / or copolymers with number average molecular weights between 2000 and 500000, produced by polymerization of

A. amino group-containing monomers of the general formula I

Rl - CH

in which R and R ² each represent a hydrogen atom or a methyl group, R ³ and R ⁴ each represent a hydrogen atom or a Cι_4-alkyl group or a piperazine, piperidine or morpholine radical, R-- is a straight-chain or branched-chain alkyl radical 1 to 22 carbon atoms with the proviso that the counterion to the ammonium function is a halogen, sulfate, phosphate, borate or organic acid anion, or R5 is a pair of electrons, Z is 0 or NH and n is a number between 2 and 5,

or by copolymerization of A. with

Bl. Monomeric, unsaturated acids of the general formula II

R5 - CH = CR ⁵ - C - 0H

ERSAT A ^" in which R5 and R- each represent a hydrogen atom or a methyl group, and / or

B2. monomeric, unsaturated carboxylic acid esters of the general formula III

R ⁷ - CH = CR ⁸ - C - 0- (CH, 0) R ^"

in which the radicals R ⁷ and R ⁸ each denote a hydrogen atom or a methyl group and R denotes a straight-chain or branched-chain alkyl group having 1 to 22 C atoms, m represents numbers between 2 and 4 and p is a number between 0 and 18 with the proviso that if p = 0 the content of unsaturated carboxylic acid esters in the copolymer does not exceed 30% by weight and / or

B3. Acrylamides and / or Methacryla iden that the

Amide nitrogen atoms can be substituted by straight-chain and / or branched-chain alkyl radicals having 1 to 22 carbon atoms and / or

B4. N-vinyl pyrrolidone,

are opened and then the ink particles are removed in a manner known per se by flotation or washing out of the fiber suspensions.

2. The method according to claim 1, characterized in that in the general formula I the radicals R * hydrogen, R ² hydrogen or methyl, R ³ and R ^{4 are} each methyl or ethyl, R-- a pair of electrons or R5 is a Cι_4- Alkyl group with the proviso that

SPARE BLADE 16 the counter ion is a halogen anion, and in the general formula III the R 1 radical denotes a straight-chain or branched-chain alkyl group having 1 to 8 C atoms.

3. The method according to one or both of claims 1 to 2, characterized in that waste papers are opened in the presence of at least partially water-soluble polymers and / or copolymers with number average molecular weights between 5000 and 200000, preferably between 10000 and 100000.

4. The method according to one or more of claims 1 to 3, da¬ characterized in that waste paper containing waste paper parts from paper printed with water-dilutable printing inks are opened.

5. Use of at least partially water-soluble polymers and / or copolymers with number average molecular weights between 2,000 and 500,000, produced by polymerization of

A. amino group-containing monomers of the general formula I

R- - CH = CR ² - in which R * and R ² each represent a hydrogen atom or a methyl group, R ³ and R ⁴ each represent a hydrogen atom or a Ci-4-alkyl group or a piperazine ,. Piperidine or morpholine radical, R ** - * is a straight-chain or branched-chain alkyl radical having 1 to 22 carbon atoms with the proviso that the counterion to the ammonium function is a halogen, sulfate, phosphate, borate or organic

REPLACEMENT LEAF Is acid anion, or R5 is a pair of electrons, Z is 0 or NH and n is a number between 2 and 5,

or by copolymerization of A. with

Bl. Monomeric, unsaturated acids of the general formula II

0

R ⁵ - CH = CRδ - C - OH

in which R5 and R- each represent a hydrogen atom or a methyl group, and / or

B2. monomeric, unsaturated carboxylic acid esters of the general formula III

0

R ⁷ - CH = CR ⁸ - C - 0- (Ci? .H-2m0) p R ⁹

in which the radicals R ⁷ and R ⁸ each denote a hydrogen atom or a methyl group and a straight-chain or branched-chain alkyl group having 1 to 22 C atoms, m represents numbers between 2 and 4 and p is a number between 0 and 18, with the proviso that if p = 0 the content of unsaturated carboxylic acid esters in the copolymer does not exceed 30% by weight and / or

B3. Acrylamides and / or Methacryla iden that the

REPLACEMENT LEAF Amide nitrogen atoms can be substituted by straight and / or branched chain alkyl radicals having 1 to 22 carbon atoms and / or

B4. N-vinyl pyrrolidone,

for deinking waste paper.

6. Use according to claim 5, characterized in that at least partially water-soluble polymers and / or copolymers with number average molecular weights between 5000 and

200,000, preferably between 10,000 and 100,000, can be used.

7. Use according to one or both of claims 5 to 6, characterized in that the at least partially water-soluble polymers and / or copolymers are used for deinking waste papers which contain waste paper components made from papers printed with water-dilutable printing inks.