CA2240959A1 - Process for removing inks from waste paper - Google Patents

Abstract

A process for removing oil-based inks and/or waterborne inks under slightly acidic, neutral or alkaline conditions by using either a flotation technique and/or a washing technique by using a novel deiking agent having a quartenized nitrogen group is provided.

Description

CA 022409~9 1998-06-18 W O 97/22751 PCT~B96/01407 PROCESS FOR REMOVING ~NKS FROI\~ ~,VASTF. PAPER

BACKGROUND OF T~IE INVENTION

I . Field of the Invention The present invention relates to a process for removing hlks from waste paper More particularly, the invention relates to a process for deinkin, ~lste paper comprising the steps of converting waste paper to a pulp, contacting the pulp with a deinking agent comprising an agueous dispersion of a surface-active copolymer bearing quaternized nitrogen atoms and removing ink from the pulp.

2 . Technology Description Waste paper has long served as a source of raw fiber material for paper making for the production of a variety of paper and paperboard products Today, greater utilization of reclaimed fiber has provided incentive for taking steps to upgrade the reclaimed product. These processes include steps to effectively remove ink from waste fibers in order to permit their use in the manufacture of, for example, newsprint and hygiene paper and high quality papers.

Therefore, ef~lcient ink removal is particularly desirable to obtain e~cellent guality~
high value products.

In the course of conventional paper reclamation, the deinking processes essentially comprise the following steps:
I) pulping the waste paper, i.e. fiberizing it in water 2) contacting the pulp with an alkaline agueous deinking medium containing a chemical deinking a,gent.
The physical pulping and the alkalinity of the agueou~s mediuln cause at least the partial removal of ink from the pulp fiber The deinking a,~ent completes CA 022409~9 1998-06-18 W O 97n27~1 PCT~B96/01407 this removal and produces an aqueous suspension and/or dispersion of the ink particles.

3) Removing the detached suspended dispersed inl~ t'rom the pulp This separation can be carried out by washing and/or flotation techniques well know in the art.

Steps ( I ) and (2) can be performed at least partly at the same time.

There are basically two main different kind of inks:
- Conventional inks or oil-based inks are based on organic solvents, mineral oils, hydrocarbons and nitrocellulose. Suitable solvents are for example esters/or ketones, for example ethyl acetate, methyl ethyl ketone and alcohol and organic resins.
These conventional inks are most of the time well detached tiom the fibers during pulping in an alkaline medium and well removed during a subseguent flotation step with an appropriate deinking agent.
-Waterborne inks mainly used in flexographic printing of newspapers have been developing over several years.

The reason for the increased use of waterborne printed inl~s are environmentaly based There are also safety and economic reasons for using them. Waterborne inks are non-flammable which eliminates the need for expensive sat'ety svstems wllich have to be installed in plants where oil-based inks are used. In addition lo that, waterborne inks have the further advanta,,es of reducing pproblems durin;, start-up of the printing machine and increase the possibility of utilization of lower basis weight papers.

However, waterborne inks, more particularly in waterborne flexographic printed newspapers, lead to great deinking difficulties which can make flotation de-inking plants inefficient.

Another difficulty is to pulp a batch of reclaimed paper without any flexographic printed newspaper in it In fact most of the time the reclaimed waste papers are mixed together and it is impossible or at least uneconomical to separate the two different CA 022409~9 l998-06-l8 W O 97/227~1 PCT~B96/01407 inks. Or the impact of using some waterborne hll~s on conventional deinking processes is severe; inclusion of as little as 5% flexo,raphic ne~Yspapers into a newsprint recycle furnish, can significantly reduce the brightness of the recycled pulp.

Conventional practice has been to process flexographic newsprint using ~ ash deinking processes. While wash deinking is easy to operate, and re(luires minimal capitalinvestment, the large volumes of water required make wash deinking an increasingly environmentally unacceptable practice The paper industry as a whole is under severe pressure to reduce rates of water consumption. As a result the trend in the recycled paper industry is towards use of flotation or hybrid flotation/wash systems for ink removal. Flotation is particularly ill-suited for removal of waterborne ink from recycle newsprint as both the small particle size and hydrophi]ic natllre of the inl; result in poor rates of bubble attachment and low separation effciencies The poor effectiveness of flotation in removal of waterborne inks is a particular obstacle to recycling newsprint so contaminated, and in some cases restricts tl-e acceptance of the use of waterborne inks as a means to reduce emissions of volatile organic compounds.

There have been proposals describing a two stage process to remove waterborne pigments using a flotation step under acidic conditions followed by a flotation step under alkaline conditions. Maintenance of acid conditions Ihnits the hydrophilicity of the pigment particles, and reduces the de~,ree of dispersion of' sucll in~s. The benefit of this procedure is avoidance of the high water consumption of a wash system, however the capital and operating costs of this process are greater than that of a single flotation stage process, and in addition pulping under acidic conditions is difficult if the waste paper contains alkaline fillers such as calcium carbonate.

In Borchardt et al (TAPPI 1994 Pulping Conference, November 6-10 Proceedings pages 1067-1103) many of the difficulties of recycling flexographic newsprint are described in detail; in particular the extremely small size and hydrophilic nature of the pigment particles, and difficulty in removing them b)~ either wash or flotation unit operations. Borchardt also discloses polyacrylates as effective in reducing redepositon of pigrnent in these applications.

CA 022409~9 1998-06-18 wo s7n27sl PCTnB96/01407 In WO 93l21376 the use of anionic polymers as aides in deinking wastepAper undersubstantially neutral conditions is described. This reference stresses that its process cannot be used at a pH of greater than 9 as yellowing of the pulped fibers can occur.

US 5,094,716 describes the use of a combination of an anionic surfactant and an anionic dispersant for use in removal of hydrophobic inks in wash processes, This reference does not suggest the use of its process for treatment of hydrophilic inks or the use of a nonionic surfactant.

US 4,599,~90 describes the use of polyelectrolyte dispersants in combination with nonionic surfactants in wash deinking of secondary fiber. This process su,,gested is not a flotation process and it is unclear from the teaching oi' the reference if it can be used to treat hydrophilic inks.

Canadian patent 2~003,40~ relates to a composition for deinking wastepaper comprising an at least partly water soluble polymer.

Despite the above teachings their still exists a need in the an for a process for removing oil-based inks and/or waterborne inks under slightly acidic, neutral oralkaline conditions by using either a flotation technigue and/or a washing technique by using a novel deinking agent.

BRIEF SUMMARY OF T~E INVENTlON

In accordance with the present invention a novel process for deinking wastepaper is provided which reveals a surprising combination of beneficial effects under the conditions of slightly acidic, neutral or alkaline treatment and which can be efficient either on waterborne inks and/or on oil-based inks.

All percentages and ratios given are on a weight basis unless otherwise indicated.

CA 022409~9 1998-06-18 One of the embodiment of the present invention pro~ides a process for deinking wastepaper comprising the steps of:
(1) converting wastepaper to a pulp, (2) contacting the pulp with a deinking agent compl-ising an agueous dispersion of a surface active copolymer of:
(A) from about 0 1 - 99.5, more preferably from about 5 - 9~, most preferably from about 20 - 9~ weight percent based on total weight monomers of at least one vinyl monomer having at least one quarternized nitrogen atom;
(B) from about 0 - 95, more preferably from about 0 - 70, most preferably from about 0 - 60 weight percent based on the total weight of the monomers, of at least one vinyl monomer having at leas~ one amide group, (C) from about 0 5-75, more preferably from about 5 - 50~ most preferably from about I - 50 wei,ght percent based on the total weight of the monomers, of at least one vinyl monomer bearing both an hydrophobic and an hydrophilic group, (D) from about 0 -10, more preferably from about 0 - ~ weight percent, based on the total weight of the monomers, of at least one vinyl monomer bearing at least one carboxylic group, and (3) removing ink from the pulp:
with the proviso that the sum of the percentages of monolllers (A) to (D) is 100.

The ammonium monomers (A) are preferably of the formula:

H2C = CH~2HC CH2----CH = CH2 \ / _ N X

R, R2 CA 022409~9 1998-06-18 in which R~ and R2, identical or different are C,-C" all~yl sucll as metllyl~ ethyl, propyl and hexyl. More preferably R~ is the same as R2 and is n~ethyl or ethyl Generally speaking the counter ion (X)~ of the ammonium atom i.s any ntineral and/or or~,anic anion, such as chloride or sulfate.

These preferred monomers are dimethyldiallylammoniulll chloride or sulfate and diethyldiallylammonium chloride or sulfate.

Others preferred monomers (A) are selected from the group consisting of (meth)acryloyloxyethyltrialkylammonium (chloride or methylsulfate), (meth)acryloyloxyhydroxypropyltrialkylammonium (chloride or methylsulfate), (meth)acrylamidopropyltrialkylammonium (chloride or methvlsulf'ate) It is also possible to use a precursor of monomer (A). This precursor can be a vinyl monomer having a nitronen atom which can be subseguently guarternized durin~ or after the polymerization. These precursors can be selected from the group comprising -vinyl pyridine or vinyl amines such as (meth)aclyloyloxyethyltrialkylamine, (meth)acryloyloxyhydroxypropyltrialkylamine modified with ~lycidyltrialkylammonium chloride, -vinyl amides such as (meth)acrylamide includin~ N-substitLIted analogs thereof modified throu~,l1 the Mannich reaction, either pre or post polvmerization, which can be subsequently quarternized v~ith methyl chloride~ benzyl chloride ordimethyl sulfate, -(meth)acrylic acid modified with glycidyltrialkylammoniuln chloride durin;, preor post polymeri2ation, -vinyl formamide hydrolyzed during pre- or posl-polymerization, and the inorganic salt or quarternized derivatives thereof Other monomers containing amino or ~uarternary amino ~Iroups are disclosed in U.S.
Patent 3,766,156 the disclosure of which is incorporated herein by reference.

Suitable monomers ~B) are for example of the formula:
H2C = C(R~) - C(O) - N(R~R5) CA 022409~9 1998-06-18 W O 97/22751 PCT~B96101407 in which R- is H or C, - C,, alkyl, T~ and R~ which can be identical or difl~erenl are H
or C, - Cl2 hydrocarbon radical such as alkyl, aryl~ alkylaryl or arylalkyl E:;amples of alkyl groups are methyl, ethyl~ propyl, ethyl-2 hexyl and dodecyl~ exalnples of aryl groups are phenyl and naphthyl~ examples of alkyl aryl aroups are methylphenyl~
ethylphenyl, examples of arylalkyl groups are phenyl methyl and phenylaliiyl Examples of suitable monomer (B) are (meth)acrylamide or an alkyl or diall;yl N-substituted (meth)acry1amide and N-(dimethylaminoethyl) acrylamide.
It is possible to use a part of the monomer (B), as a precursor for at least a part of the monomer (A) for example by quarternizing (B), before or after polymerization with a quarternizing agent such as methyl chloride as indicated above.

The copolymer also comprises from about O ~-40 ot' monon)er ((')~ more preferably, from about I - 40~ most preferably from about 10 - '0 we~;,ht percent of at least one vinyl monomer bearing both an hydrophobic and an hydrophilic aroup. based on thetotal weight of the monomers. More particularly monomers (C) can be of the formula:
H2C = C(RG) - C(O) - O - [CH2CH(R7)0]m - (CH2CH20)" - R,~
wherein R,, is H or C, - C,, alkyi group, preferably H or methyl;R~ is C, - C~ alkyl, preferably methyl; n is an averaae number from about 6 - 100~ pret'erably 10 - 40 and In is an average number from about O -~0, prefèrably O - 10, provided that n is superior or equal to m and sum of (n + 111) is about 6 - 100; R~ is a hydropi-obic C~ - CJ~ linear or branched alkyl, alkylaryl, or arylalkyl group, preferably a Cl~ - C~" all;yl~ more preferably a C,2 behenyl radical or a tristyrylphenyl aroup of the f'ormula:
-- O -[CH(CH~) - O ] ~
wherein x is an average number of from about '7 to about '. wherein tl-e substituellt denoted x is randomly distributed around the benzene rin(~ to which it is linked.

The above monomer can be obtained by the reaction of a vinyl monomer of an ester ot' (meth)acrylic acid with an alkoxylated alcohol or alkoxylated polystyryl phenoi or by any other known process.

The vinyl monomer of the formula:

CA 022409~9 1998-06-18 WO 97~27SI PCT~B96101407 H2C = C(F~ C(O)- 0 -[CH~CH(R7)~]"~-(CH2CH~0),~- R~
in which R6, R7. Rg, m and n have the meaning indicated above for the formula ofmonomer (C). These are described in detail hl European Patents EP 011,806, EP
013,836 and in US Patent Application SN 0S/3 17,261 filed October 3. 1994, the disclosures of which are incorporated herein by reference.

The copolymer can also comprises for some purposes from O to abo~lt 10 weigllt percent of at least one vinyl monomer (D) bearing at least one carboxylic group, more particularly of the formula:
R~CH = C(R,~,)COOH
in which R9;S H, C(O)OY or CH~, wherein when R,, is H, Rl" is H, C, - C~ alkyl, or CH2 COOY; when R9is COOY, R", is 11 or CH~COOY; or when R., is CH~ Rll, is H, Y is E~ or C,- CJ alkyl Among these monomers, acrylic or methacrylic acid or a n)ixture thereof with itaconic or fumaric acid are preferred, but crotonic and itaconic acid and half esters of these and other polycarboxylic acids such as maleic acid with C, - C~ alkanols are also suitable, particularly if used in minor amount in combination with acrylic or methacrylic acid. For most purposes, it is prefèrable to have at least about 0.5 weight percent and most preferably from about I - ~ wei~ht percent of the carboxylic acid monomer.

The copolymer can be a statistical blocl~ or se(luenced polymer Most of the time it is a statistical copolymer In a preferred embodiment of the present invention the relative guantity of monomers (A), (B), (C) and optionally (D) are chosen in order to provide a surface activepolymer dispersion with a molecular weight M~ between about S,000 and about 5,000,000 more preferably between about 10,000 and about 2,000,000 daltons.

The term ' vinyl monomer" as used herein means a monomer comprising at least one of the following groups:

CA 022409~9 1998-06-18 wo 97n2751 PCTnB96/01407 CH2 = C, CH2 = CH, CH = ~H

Pol~merization of Cor)olvmer The liquid dispersion copolymers of the invention can be conveniently prepared from the above-described monomers by conventional polymerization techniclues in water at a pH lower than about 9 0 but greater than 3. preferably about 7 using, free-radical producing initiators, usually in an amount from 0 01 percent to 3 percent based on the weight of the monomers The free-radical producing initiators conveniently are peroxygen compounds especially inorganic persulfate compounds such as ammonium persulfate, potassium persulfate, sodium persulfate~ peroxides such as hydrogen peroxide; organic hydroperoxides, for example~ cumene hydroperoxide, t-butyl hydroperoxide; organic peroxides~ t'or example, benzovl peroxide, acetyl peroxide~
lauroyl peroxide, peracetic acid, and perbenzoic acid (sometilnes activated by a water-soluble reducing agent such as ferrous compound or sodil~m bisulfite) These initiators are preferably water soluble such as 2,2' azobis (N,N' - dimethyleneisobutyramidine)dihydrochloride 2,2' azobis (2-amidino-propane) dihydrochloride 2~2' azobis (N~N' - dimethyleneisobutyralnidine) Optionally a chain transfer ag~ent can be used Representative chain transfer agents include carbon tetrachloride~ bromot'orm, bromotrichioromethane~ long chain alkyl mercaptans and thioesters such as n-dodecyl mercaptan, t-dodecyl mercaptan, octyl mercaptan, tetradecyl mercaptan, hexadecyl mercaptan, butyl thioglycolate, isooctyl thioglycolate, and dodecyl thioglycolate The chain transfer agents can be used in amounts up to about 10 pans per 100 pans of' polymerizable Inonomers Optionally~ other ingredients well known in the a~lueous polymerization an may be included such as chelating agents, buffering agents~ surfactants, inorganic salts and pH
adjusting agents The use of surfactants during the polymerization process is forexample described in "Progress in Or~ranic Coatings ~4 ( 1994) 1 1-19"~ the disclosure of which is incorporated herein by reterence CA 022409~9 1998-06-18 wo s7n27sl PCTnB96101407 Usually the copolymerization is carried O-lt at a temperatul-e between about 80~ C and 100~ C but higher or lower temperatures includin~, polyn~eriz~tioll under vacuum or pressure can be used. The poiymerization can be carried out batchwise, stepwise or continuously with batch andlor continuous addition of the monolners in a conventionai manner.

The monomers can be copolymerized in such proportions~ and the resulting dispersion polymers can be physically blended, to give products with the desired balance ofproperties. Minor quantities of a polyfunctional monomer, sucll as itaconic or fumaric acid to introduce a hi~Ther carboxylic acid content or ihnited crosslinking, provides further control of the stmcture of the polymer. Thus, by varyin~, the monomers and their proportions, copolymers having optimum deinkiml propel1ies can be designedParticularly effective liguid dispersion copolymers can be obtained by copolymerization of about 0.1 - 9~, more preferably 5 - 70, most preferably I - ~0 weight percent of monomer (A), about 0.1 - 95, more preferably 10 - 70, most preferably 20 - 60 weight percent of monomer (B), abo-lt 0.~ - 40, more preferably I - 40, most preferably 10 -30 weight percent of monomer (C) and about O - 10~ more prefierably 0 - 5 weightpercent of optional monomer~D), all percenta~,es bein~ based on the tot~l wei~ht of the monomers .

The amount of surface active copolymer (calculated as dry) presellt in the a~iueous medium of the pulper ranges from about 0.01 to about ~.0 percent by weight basedupon the dry wei,~ht of all paper added to the pulper, witll amounts ran~ino from about 0.1 to about 2 percent bein~ more pret'erred.

Waste PaPer Treatment:

The paper to be pulped, which also includes by definition any cellulosic sheet materiais containin~ hydrophilic fiexogMphic inks (hydrophilic inks) and/or oil-based inl;s (hydrophobic inks) includin~, for example, newspaper, filled and unfilled papers and paper 1(~

CA 022409~9 1998-06-18 W O 97n2751 PCT~B96/01407 boards is provided to a pulper at alkaline pH conditions. Thereiore the ink pl-esent on the paper to be pulped comprises waterborne flexo~,rapllic ink and/or oil-bAsed inl;
Surprisingly it has been discovered that the deinking a(lent ~ccordin~r to the present invention is suitable for use in a medium having a pH of from slightly acidic (about ~ to 6), neutral (about 6 to 8 ) or alkaline (about ~ to 10.5). A neutral or an alkaline pH is preferred.

The pH ofthe aqueous medium ofthe pnlper can be preferably maintained between abo~lt 8 to about 10.5, more preferably between about 9 to about 10, and most prefèrably between about 9 to about 9.5 This alkaline pH range is particlllarly useful with paper containin(r more than about 50 % of oil-based inks Maintenance of the alkaline pH is accomplished by adding one or more basic agents to Ihe pulper. Agents which may be selected incl~lde any of those commonly known in the alt which are capable of raisin~, the pH to between 8.0 and about 10.5 Examples of such basic aaents include but are not limited to the following materials: of NaOH~ NH~OH, KOH~ Na2CO, K2CO~, silicates (Na2O (SiO2)~)x=0.4 to 4.0, Na~PO~ Na2HPO~ and mixtures thereof The amount of basic a(~ent added lo the pulper is that which is required to obtain the desired pH. This amount can be readily measured by those skilled in the art.

According to one preferred embodiment of the invention one or more nonionic surf'actants can be further added in the aquec)us mediuln of the ~ulper more partic~llarlv when mc)re than 50 % of the ink is oil- based h-k. Tlle sulfàctants tilnction is to ciisperse the ink into the aqueous medium during pulping. Nonionic surfactants suitable fol use are hi;,her(greater than Cs) aliphatic alcohol alkoxylates~ aliphatic acid alkoxylates~ higher aromatic alcohol alkoxylates, fatty acid amides of alkanolamines~ t'atty acid amide alkoxylates~ propylene glycol alkoxylates~ block or randoln copolymers of ethylene and propylene oxide~ higher (greater than Cs) alcohol polyethylene polypropylene block or random adducts and mixtures thereof Specific examples of sulfactants which may be used in accordance with the present invention inci~lde the t'ollowin,, classes of chemicals:

W O 97n2751 PCT~B96101407 I) a fatty alcohol havin~ a carbon n~lmber ot' from abo~t 8 to about ~
alkoxylated with ethylene oxide and propylene o~ide, as represented by formula ~I) R"-O-(CH2CH20)~-(CH2CH(CH~)-O)!-Z,(I)~
wherein Rl~ is a straight-chain or branched alkyl group having a carbon number of from about ~3 to ~ Z, is H or Cl; x represents the number of oxyethylene ~,roups per molecule and is in tl-e ran,,e of from about 3 to about 25; and y represents the numbel of oxypropylene groups per moiecule and is in the ran~e of t'rom about I to about 10. Examples of commercially available products are sold under the InkMasterT~'I and Antarox"'' trademarks by Rhône-PoLIlenc Inc., 2) a fatty alcohol havin,, a carbon number of from abo-lt 8 to about ~
alkoxylated with ethylene oxide and propylene oxide as represented by formula (Il) R"-O-(CH2C~20)~-(CH2CH(CH~)-O)~-(CH2CH20)~-(CH,CH(CH~)-O)!--Z, (Il);

wherein R" is a straight-cllain or branched all~yl ~,roup havin~, a carbon number offrom about 8 to about '~'~; Zl is H or Cl~ x and ~', which may be the same or different, represents the nulnber of oxvethylene ~Iroups per molecule and is in the range of from about ~ to about ~; and y and y', which may be the same or different represents the number of oxypropylene groups per molecule and is in the ran~,e of from O to about 10 Examples of commercially available products are sold under the InkMaster trademark by Rhôlle-Poulenc Inc.~

3) a fatty acid havin~, a carbon number of from about 8 to about ~, alkoxylated with ethylene oxide and propylene oxide, as represented by formula (1~1) R"-C(O)O-(CH2CH,O)~-(CH,CH(CH~)-O)~ -Zl (111);

W O 97~2751 PCT~B96101407 wherein R" is a straight-chain or branched all;yl ~roup havina a carbon number of from about 8 to about ~ 7; Z, is H or Cl x represents the number of oxyethylene ~roups per molecule and is in the ran~Je of from about 3 to about 25, and y represents the number of oxypropylene groups per molecule and is in the ran ,e of from about 2 to about 15.
Examples of commercially available products are Lionsurf, Nonatell'~'~
Hipochem'X' and BerocellK products sold respectively by Lion Industries~ Inc.~ Shell Oil Company Higl1 Point Chemical Corp. and EKA Nobel AB;

4) an aromatic alcohol such as phenol llavin~ alkyl chain(s) with a carbon number of from about 8 to about ~0 alkoxylated with ethylene oxide~
as represented by formula (IV):

(R~2) (R~ (OCH2CH2)~-OZ, (IV)~

wherein ¢l is a phenyl ring~ R,2 and R,, independently are H or an alkyl group which is branched or straight-chain having a carbon number of from about 8 to about 14; Z, is H or Cl~ and x is the number of oxyethylene 2roups per molec~lle and is hl the ran~e ot' from about I to about ~0. Examples of commerciallv available products are InkMasterT~'1 IgepalK and Alkasulf'K~ products sold by Rhône-Poulenc Inc.;

5) fatty amide of alkanolamide of formula (~/) R"-C(O)-N-R' (V);
11.'' wherein R' and R" may be the same or different and are H or CH2CH20H or CH2CH(C~H.)-OH and R" is a t'atty alkyl group having a carbon number of from about 8 to about ~0 Examples of CA 022409sg 1998-06-18 W O 97/22751 PCT~B96/01407 commercially available products are Alkamide products sold by Rhône-Poulenc Inc.;

6) an alkoxylated fatty acid amide of alkanolamide of t'orlllilla (Vl).
- C(O)-N-(CH2CH2O)~
(CH2CH20)~'-Z, (Vl) wherein R" is a fatty alkyl group havingr a carbon number of from about 8 to about 20; Z~ and Z,', which may be the same or dil'ferent are H or Cl; and x and x', which may be the same or different represents the number of oxyethylene groups per molecule and is in the range of from about 2 to about 10. Examples of commerciallv available products are Alkamide"' products sold by Rhone-Poulenc Inc..

7) a propylene ~llycol alkoxylate offormula (Vll) Z,O-(CH2CH2O)" (CH-,CH(Ci l~)-O)n~ (C'i S~CH-O)l,-Zl' (Vll) wherein Z, and Z,', which may be the same or different are H or Cl; o and p are the number of oxyethylene groups per molecule and are in the range offrom about 3 to about 15 and m is the number of oxypropylene groups per molecule and is in the range of from about 2 to about 4( Exampies of commercially available producîs are AntaroxR products sold by Rhône-Poulenc Inc. and products havill~ a ( TFA desi~rnation ot Poloxamer;

8) a block or random copolymer of ethyiene and propylene oxide of formuia (VIII):
Z,O (CH(CH )CH2O)"~ (CH~CH2O)" (CH(CH~)CH2O)" Z, '(Vlll) wherein Z, and Z,', which may be the salne or different are H or Cl; m and n are the number of oxypropylene glolll)s per molecule and are in the range of from about 10 to about 25 and p is the number of oxyethylene groups per molecule and is in the range of trom about 5 tc-about 25. Examples of commercially available products are AntaroxR

W O 97~2751 PCT~B96/01407 products sold by Rh(')ne-Poulellc Inc. alld prodLIcts ha~ in ~ a CTF.
designation of Meroxopol;

9~ an ethoxylated fattv acid glycol and/or polyethylene gl!col esters of formula (~X):
R,5-C(O)0-(~H,CH20).~-R" (IX) wherein R,5 is a fatty all;yl g roup of yreater than C~; R" is alkyl of greater than Cx or H; and x represents the number ot oxvethylene groups per molecule and is in the range of from about ~ to about 200.
Exarnples of commercially available products are AlkamLIs products sold by Rhône-Poulenc ~nc. and products havin(l a PEG castor oil CTFA designation; and 10) an ethoxylated t'atty alcohol offolltlLIla (~) R,iO(CH,CH20)~-ZI (X) wherein R~5 is a fatty alkyl group; Z, is H or Cl and x represents the number of oxyethylene groups per molecule and is in the range of from about I to about ~0 Examples ot' commercially avaiiable products are RhodasurfR products sold by Rhône-PoLIlenc Inc More preferred nonionic surfactants within tl-e above classes inclu~3e:

I) Those of Formula (I) wherein R" is a straight-chain or branched alliyl group havin~ a carbon number of t'rom about 16 to ~0~ Zl is H~ x represents the number of oxyethylene (JlOUpS per molecule and is in the range of from about 10 to about ~0~ and y represents the null1ber of oxypropylene groups per molecule and is in the range of from about 4 to about 8. A commercial example of such a nonionic surt'actant is InkMasterT~ 7~0; or wherein R" is a straight-chain or branched all~yl yroup having a carbon number of froln about 8 to 14~ Z, is H~ x represents the number of oxyethylene ~roups per molecule and is in the range of from about ~ to about 1 ' and y represents the number of CA 022409~9 1998-06-18 W O 97~2751 PCTnB96/01407 oxypropylene (Jroups per molecule and is in the ran2e of from about I
to about 6 A commercial example of sucll a nonionic surfactant is Antarox@~) LA-EP-16 sold by Ri-ône-Poulenc 2) Those of Formula (Tl) wherein R, I is a strai~rht-chain or branched alkvl group having a carbon number of from about 16 to about ~0 Z, is H x and x represents the number of oxyethylene ~roups per molecule and is in the range of from about 4 to about 10 and y and y represents the number of oxypropylene groups per molecule and is in the ran~re of from about I to about ~

3) Those of Formula (1ll) wherein R" is a straigtlt-chain or branched all~yl group having a carbon number of from about 1~ to about 1 S Z, is H~ x represents the number of oxyethylel1e 2roups per molecule and is h~ the range of from about 3 to about ~5 and y represents the numbel- of oxypropylene groups per molecule and is in the ran~e of from about ' to about 15 A commercial example of such a nonionic surfactal1t is Hipochem~ D1600 sold by Hi2h Point Chemicals;

4) Those of Formula (IV) wherein Rl2 and R, is H or a branched or straight-chain havin~i ~ carbon number of from about S to about 14~ Zl is H and x is the number ol' oxyethylene ~ roups pel molecule and is in the ran~ e of from abollt S to about 1~ A commercial example of sucl a nonionic surfactant is InkMaster'~ 7~0;

5) Those of Formula (V) wherein R and R are H or CH2CH20H or CH2CH(CH~)-OH and R,l is a fatty alkyl 2roup havin~ a carbon number of from about ~ to abo~lt 14;

6) Those of ~ormula (Vl) wherein R" i5 a fatty alkyl ~rroup havin~J a carbon number of from about S to about 14~ Z, is ~1 and x and x 1(~

CA 022409~9 1998-06-18 W O 97~2751 PCT~B96101407 represents the number of oxyetllylene ~roups pel- molecule and is in the range of from about 4to aboul 8;

7) Those of Formula (IX~ wherein R,s is a tatty al~-yl group of greater than C~; Rl" is alkyl of greater than Cx or H; and x represents the number of oxyethylene groups per molecule and is in the range of from about 8 to about 30; and 8) Those of Formula (X) wherein Rls is a fatty alkyl ~roup having a carbon number from about 1~ to about 18~ Z, is H~ and x represents the number of oxyethylene ~roups per molecule and is in the range of from about S to about 1~ A commercial e:~ample of such a nonionic surfactant is RhodasulfO BC7~0, sold by Rhone-Poulenc Inc.~

Of the above, the use of the followin~ classes of nonionic surfàctants is particularlv suggested: those of Formula (1), (Il), (IX) as defined above.

Other nonionic surfactants include alkyl polyglycosides~ N-octyl pyrollidones and ethoxylated tristyrylphenols.

The amount of surfactant present in tl-e a(lueous medi~lltl of the pulper ranges fi-o m about 0.01 to about ~.0 percent by weig~ht based upon the dry wei,ht of all pal)er added to the pulper, with amounts ran~,hlg from about 0.0~ to about 0.5 percent being more preferred and amounts ran~ring from about 0.0~ to about 0.4 percent being even more prefe" ed.

Also optionally present in the aqueo-ls medium of the pulper may be one or more anionic polyelectrolytes. Such materials are characterized by beina anionic in nature and function to reduce redeposition of the carbon blacl< pigment to the pulp fibers Optionally present in the agueous medium of the pulper are commonly known deinking additives added in amounts recognized by those skil]ed in the art. Such additives include, but are not limited to bleaches. sodium silicate, chelants, se(luestrants~

CA 022409~9 1998-06-18 W O 97~2751 PCT~B96101407 dispersants other than the defned nonionic surfactal1t co~ulants~ cieter(lent builders, other detergents and the like. In addition, the pulper may also inciude an amount of newsprint printed with a hydrophobic ink.

It is important to maintain an appropriate pLlip slurry temperatLIre during pulping.
Determining the appropriate temperature range is within the sliill of an artisanGenerally the range is from about 30 C to about 65' C, preferably t'rom about 35"C to about 60~C and most preferably from about 40"C to about ~ . Once the paper addedto the pulper has been sufficiently slurried in the aqueous mediuln~ tlle slurry is transferred to a flotation cell. As is defined for the pulping, the flotation cell can be maintained witll a pH of from slightly acidic (abollt 4 to 6), neutral (about 6 to ~ ) or alkaline (about 8 to 10.5). A neutral or an alkaline pi~ is pretèrred.

The pH of'ten is the pH of the slurry which is provided to the ~lotation cell. If necessary to provide the desired pH profile, one or more of the basic agents, acidic a~,ents or buffered agents can be added in amounts to yield a pH in the flotation cell as defined above.

The slurry is maintained in the flotation cell for a thne~ temperat-lre and rate of a~fitatic necessary to produce a foam which contains a si,nificant amollnt of tlle removed ink. Sucll process conditions are pret'erably those operatin~, conditions which are defined by the manufacturer of the flotation cell. Such conditions typically comprise treating the slurry at about 40~C to about 50"C for about I to about 30 minute~ injectin~ air h1to the cell in an amount sufficient to disperse air bubbles throu,,ho-lt the mixture~ with good at~itation anci without becoming so turbulent as to dislodge ink from the air bubbles. This amoullt of injection is typically about I cell volume of air per min-lte. The concentration of the paper fibers is about 0.5 to about ''.0% ofthe cell.

Once flotation has been completed, the foam which fonns above the slurry in the flotation is removed by methods known in the alt such as by a scraper From the remainin~ slurry~
paper can be produced which has a hi~,h level of brightness.

IX

CA 022409~9 1998-06-18 W O 97/22751 PCTnB96/01407 Alternatively, the remaining slurry may be subjected to additional processing steps sucll as post flotation wash procedures as would be reco,nized by those skilled in the art to yield even more superior paper products.

The deinking agent of the present invention comprising the dispersion ot' the surface active copo)ymer and preferably the nonionic surfàctant can be added in the water into wllich the wastepaper is initially pulped; into tl-e aqueous pulp produced after the wastepaper is pulped; or during the flotation andJor washin~ step. Preferably the deinl~ing a~ent is incorporated af~er the wastepaper has been pLllped, i.e. during the flotation step.

The invention is f'urther described in greater detail by the following non-limiting e~amples.

EXAMP~E I
A) Polymerization of a Surfàce Active DMDAAC/SEM/Acrylamide Copolymer (P,):
A reactor comprising a I liter electrically heated resin flask with a fo~lr necli top w~s utilized. A condenser using tap water as the cooling medium was fitted to one neck; the agitator shaft entered throu~h the central neck, sealed throu~,h a Teflon fitting and a O-ring lubricated with silicone grease; monomer was fed through a stainless steel tube inserted in a rubber stopper in the third neck; a temperature probe~ initiator feed and N2 were fed through tubing in a rubber stopper in the fourtll neck The condenser dischar,e was bubbled throuoh water to maintain a positive pressure in the reactor. Agitatioll was provided by a stainless steel ~.~ millimeter diameter Liglltnin' hi=,ll efficiency a!;ial flow turbine set near the bottom of the flask~ operating at ~00 RPM.Temperature was controlled via a temperature sensor connected to a three mode controller usin(r time-proportionill~, to modulate the electrical heatino of the reactor. Monomer was fed into the reactor using a positive displacement pump over a two hour period. Initiator solution was fed into the reactor using a separate positive displacement pump over the same two hour period.
Nitrogen was sparged into the reactor mass at a rate sufficient to maintain a positive pressure of about I H~, centimeter. For most reactions this corresponded to a flow rate of about 0.75 liter/min at 3 bars.
Initially, the reactor ch~rge (RC) had the f'ollowin(~ composition:

I') W 0 97~2751 PCT~B96101407 0.16 gm ammonium persulfate~ 0.019 =m Versenex 80 (40~~0 cliethylentliamille pentaacetic acid or (DTPA) solution) and 200 gm of deionized water were introduced into the reactor and thereafter the monomer feed and the initiator teed were introduced into the reactor The monomer feed (MF) had the following composition 14.64 gm oftristyrylphenol polyethoxylate (40 EO) metllacrylic ester (SEM) having the formula:
H2C = C(CHl)--C(O) - O -- (CH2CH2O)~" O- [CH(CH~)-O]~
81.5 gm of a 53% aqueous acrylamide solution 68.42 gm of 6~% aqueous solutioll of dimethyldiallyiamlllonium chloride (DMDAAC) and 84.22 ~m of deionized water and 0.61 gJm of MAA (metllacrvlic acid) The initiator i'eed (~F) had the following composition:
50 gm of deionized water 1.08 gm of ammonium persulfate 60 ml of deionized water and one drop of 15% aqueous NaOH (by weight).

The reaction was performed at pH about 7 and at a temperature Of 90c C. The reaction mass was held at 90~ C after completion of feed of initiator and monomer for 0 Ininlltes The copolymer obtained was called (P,) B) ~valuation of Resultino Copolymer (Pl):

The evaluation procedure used was as follows:

(I) FONP stands for water based flexograpilic old printed newsprint. The FONP was Knoxville News - Sentinel. ONP stands for old newspaper. The ONP was New Yorl;
Times. OMG stands for old magazines A 30% FONP/40% ONP/ 0% OMG mixture of wastepaper was used.
(2) OMG was previously pulped at about 3.6% consistenc~ in a Waring laboratory blender for 2 min~ltes without chemicals at 45~ C at a pH of about 9 5 This pulp was then 2(~

W O 97/22751 PCT~B96101407 added to the FONP and ONP in a Kitchen Aid mixer with a tenlperatllre bath and blended for 5 minutes at an intermediate speed settin~,. 1% hydro~en peroxide (50%), sodium silicate (PQ Corp. Type N), NaOH (0.~%) were added to the pulper Percentages are 011 a dry fiber basis. 0.1% of Rhoditek 1000 was also added Rhoditek 1000 is a C16-20 ethoxylated (20 EO) - propoxylated (8PO) surtàctant.

(3) The resulting pulp was diluted to 1% consistency (4) The pulp was then submitted to flotation in a Denver Cell (~ L capacity, 3 liter/min air injection, 3 min flotation time, 2100 rpm) with reject collection and polymer P was added.
The p~ was about 9 2 (5) Flotation accepts were dil-lted to 0 ~% consistency ~ind a lilter pad was prepared by filtration through crepe filter paper under vacuum. The fiitrate turbidity was measured using a Hach Ratio~' XR turbidimeter.

(6) The filter paper was stripped from the filter pad, the pad was pressed and dried overnight according to TAPPI standard method 204. The pad was tilen cut into 7 equal wedges, stacked and brightness measurements taken of each segment, top and bottom using a Technidyne Handibright calibrated using white and yellow ceramic standards supplied by the equipment manufacturer.
The following results were obtained and are gathered in Table I hel-ein a~er I '-)!
!merSolutio~ (y~ ;pl3nyll~ t~ L~ cL~lyll~
NTU

2 49. 1 48.2 6~ i 033 4~. 1 47.8 166 974 * Polymer concentration of the pnlymer solution is 20 % hy wei~llt A) Polymerization of copolymer (P,).

W O 97~2751 PCT~B96101407 The same process as in Example I was performed except that the colnpositions of (MF), (IF) and (RC) were as t'ollows:

Monomer Feed (MF) lauryl methacrylate 3 89 grams DMDAAC 62% aqueous solution 77 ~8 grams Acrylarnide 91.68 (S3% aqueous solution) grams Water 76.86 grams Initiator Feed (IF):

0.216 gm Ammonium persulfate 60 gm water I drop 15% NaOZ~

Reactor Charge (RC) 0.032 gm Ammonium persulfate 2S0 gm water 0.0168 gm Versenex 8() The polymer obtained was called (P2).

B) Evaluation of resulting Polymer (P2) The same flotation process as in Example I was pelformed e~ccept thAt (P~) was used instead of(P~) and except that no Rhoditek 1000 surfactant was used The followin, results were obtained and are ,athered in Table 2 hel-ein a~rer:

ym~r~;ol~ (yls~ lsnylbl~ --ls~ r~ llt~
NTU

2 49.99 49. '~6 1 6 l 4 ,0 45.~9 47 69 ~ 9~3 0 52.24 47~4 649 57 0.6 50.50 46 64 ~4 ~3 *: Polymer concentration ofthe polymer solution is ~0 % by weigllt.

A) Polymerization of Copolymer (P ) The same process as in E~;ample I w~s perfonnecl e~cept that tl~e compositions ot'(MF) (IF) and (RC) were as follows Monomer Feed (MF) Behenyl alcohol ethoxvlate (25 moles) methacrylic ester i 26 gra]ns Methacrylic acid 0 63 ,rams DI water 81 6 grams DMDAAC 62% a~lueous solution 109 4 l ;,rams Acrylamide 62D/o agueous solution ~6 47 ~rams Initiator Feed (rF) 0.216 gm Ammonium persulfate 60 gm water l drop 15% NaOH

Reactor Charge (RC) 0.032 gm Ammonium persulfate 250 gm water W 097n27~1 PCT~B96101407 0.0168 gtn Versenex 80 The copolymer obtained was called (Pi) B) Evaluation of resulting Polymer (P~:
The same flotation process as in Example I was performed except that (P~) was used instead of (Pl).

The following results were obtained and are (Jathered in Table 3 herein after:

NTU

2 47 97 43 93 ~6~ 1430 0 5 1 .20 ~4.~ 70~ 95~
3 46 56 46 79 ~7 1 148 *: Polymer concentration of the polymer sollltion is 20 % by weight.

In all cases (Tables 1-3) the copolymers (P,) (P,), and (P~) were successfll in reducing the filtrate turbidity of the flotation cell accepts with minilnal impact on shee~ briohtness In addition, the polymer provides an enhancement to the foamino observed in the flotation operation; in the case of Example 2 no surfactant was used demonstratin~ the potential to reduce total chemical re~luirements On the othel- hand~ in the absence of copolymer (P.) and (P-~) the filtrate turbidity is al a hi~lh level.

4 (a) Polymerization of a surface active DMDAAC/BEM/Acrylamide Copolymer (P~).

A reactor comprising a I liter electrically heated resin tlasl~ ith ~I four neck top was utilized. A condenser using tap water as the coolin, medi~lm was fitted to one neck; tl-e agitator shaft entered through the central neck, sealed through a Tefloll titting and a O-ring lubricated with silicone grease; monomer was fed through a stainless steel tul)e inserted in a rubber stopper in the third neck; a temperature probe, initiator fèed and N, were fed through tubing in a rubber stopper in the fourth neck. The condenser discharge was bubbled through water to maintain a positive pressure in the r eactor Agitation was provided by a stainless steel 52 millimeterdialnetel Li"lltllin higll eft'iciency axial flow turbine set near the bottom of the flasl~, operatin~ at 500 RPM Temperatu~e was controlled via a temperature sensor connected to a three mode controller using time-proportioning to modulate the electrical heating of the reactor l\lonomer was fed into the reactor using a positive displacement pump over a two houl- perind. Initiatol- solution WAS
fed into the reactor using a separate positive displacement P"'llr' over the same two hours period. Nitrogen was sparged into the reactor mass at a rate suf~icient to maintain a positive pressure of about I Hg centimeter. For most reactions this corresponded to a flow rate of about 0. 75 liter/min at 3 bars.

Initially, 0.16 gm ammonium persulfate~ 0.026 gln Versenex ~0 (4()% diethylentriamine pentaacetic acid or DTPA solution) and 200 gm of deionized watel- \vel-e introduced into the reactor and thereat~er the monolller tèed and the initiator i'eed were introduced into the reactor.

The monomer feed (MF) had the following composition:
27.4 gm of monomer (BEM) llaving the form-lla:
H2C = (:'(CH~) - C(O) -- O -- (CH~CH2O)2, (CH2)2, (CH ) I lOgm of a 52.5 % aqueo-ls acrylamide solution~
23.9gm of 62% aqueous solution of dimethyldiallylalllmoniuln chloride (DMl)AAC),and ~ 5.2 gm of deionized water and 13 .7 gm of MAA (metllaclyiic acid).The initiator feed (IF) had the following composition 1.0~ gm of ammonium persulfate, W O 97~2751 PCT~B96/01407 60 ml of deionized water, and one drop ot' 15% agueous NaOH (bv weigilt) The reaction was perfonned at pH about 7 and at a temperature of 90~ C The reaction mass was held at 90~ C af'ler completion of feed of initiator and monolller t'or 30 minutes The copolymer (P~) obtained had an estimated molecular weigrht o f ~0,000 daltons Repulping a series of recycle paper was then perfonned 4(b) Pulpin~r step without (P~) The used paper starting prodllct was a mixture of 3 month ~0/50 ONP/ONG (old newspapers and old magazines) withoul anv water based fle~;o~n-apllic inl~ed matters The pulping machine was of the LAMORT 15 I type with inwar(l-~low - Mixture of 50150 old paper 1500 am - Sodium silicate sollltion I I I gm (concentration 33 8% in water molar ratio SiOJNa2O 3 3) - Ethoxylated (I IEO) propoxylated (4 PO) alcohol C", - C." (RhoditekT~' 1000) ~ 2~ gm - Symperonic Tl~ (Symperonic A7 from ICI~ 7-9 EO C,,-C", alcollol) O 18 ,m - Hydrogen Peroxide 30% a(luec)us solution 50 g - Controlled hard water (3 10 ' mol/l Ca2 and I 10-'' m~Ul M~ ~ ) at 45~ C
10 liters The old Newspapers were char~ed into the pulper with all the othel- ~rodLIcts The pulping is done during I '~ minutes at a speed rotation of about ~100 RPM Tl~e pulp is then left to rest for 30 minutes The resulting pulp was diluted with tl-e controlled hard water defined above in order to obtain a 3% suspension of solid matter and a pH brought bacl~
from between ~ and 9 To this suspension was added 0 05% of (PJ) (based on the wei~rht of pulp) 2(, W O 97n2751 PCT~B96/01407 4(c) . Flotation Step The pulp obtained above was filrther diluted witll controlled ll(lrd water in order to obtain a 1% solid matter suspension~ and the pH was adjusted to 9. The flotation step is carried out in a flotation cell of LAMORT 1~1 type. The air injection valve is opened and the flotation process was done during 1~ minutes. After having rejected the foam. tl1e pulp was then filtered on a Buchner funnel. Tlle slurry obtained is then dried and its briglltness was measured according to standard N F Q 03-039. The bri~htness obtained was 63.

COMPARATI~'E E~AMPLE ~

The flotation process of Example 4 (b) and the fot,~tion process of Exalnple 4 (c) were a~ain performed except that copolvmer (P~) was not added dllrinlr the pulpi~ Thebrightness obtained was G I . From Examples 4 and comparative Example ~ it was appal-ell~
that the addition of the polymer of the inventioll si(~nificantly enhallced the brilllltness of the final pulp.

Claims (24)

WHAT IS CLAIMED IS:

1. A process for deinking wastepaper comprising the steps of (1) converting wastepaper to a pulp, (2) contacting the pulp in an aqueous medium having a pH from about 4 to about 10.5 with a deinking agent comprising an aqueous dispersion of a surface active copolymer of:
(A) from about 0 - 95 weight percent based on total weight monomers of at least one vinyl monomer having at least one quarternized nitrogenatom;
(B) from about 0 - 95, weight percent based on the total weight of the monomers, of at least one vinyl monomer having at least one amide group;
(C) from about 0.5-75, weight percent based on the total weight of the monomers, of at least one vinyl monomer bearing both a hydrophobic and a hydrophilic group, (D) from about 0 -10 based on the total weight of the monomers, of at least one vinyl monomer bearing at least one carboxylic group, and (3) removing ink from the pulp:
with the proviso that the sum of the weight percentages of monomers (A) - (D) is 100

2. The process for deinking wastepaper of claim 1 wherein monomer (C) is of the formula:
H2C=C(R6)-C(O)-O-[CH2CH(R7)O]m-(CH2CH2O)n-R8 in which R6 is H or C1 - C6 alkyl group, R7 is C1 - C4 alkyl, n is an average number from about 6 - 100 and m is an average number from about 0-50 provided that n is superior or equal to m and the sum of (n + m) is about 6 -100, R8 is a hydrophobic C8 - C40 linear or branched alkyl, alkylaryl, or arylalkyl group.

3. The process for deinking wastepaper of claim 1 wherein monomer (D) is of the formula R9CH=C(R10)COOH
in which R9 is H and R10, is H, C1 - C4 alkyl, or CH2 COOY; R9 is COOY, and R10, is H
or CH2COOY; or R9 is CH3 and R10 is H and Y is H or C1- C4 alkyl.

4. The process for deinking of claim 1 wherein monomer (A) is of the formula:

in which R1 and R2, are identical or different and are C1-C6 alkyl, and X- is a mineral and/or organic anion

5. The process for deinking of claim 4, wherein monomer (A) is dimethyldiallylammonium chloride or sulfate.

6. The process for deinking of claim 4, wherein monomer (A) is diethyldiallylammonium chloride or sulfate.

7. The process for deinking of claim 1, wherein monomer (A) is selected from thegroup consisting of: (meth)acryloyloxyethyltrialkylammonium (chloride or methylsulfate), (meth)acryloyloxyhydroxypropyltrialkylammonium (chloride or methylsulfate), and (meth)acrylamidopropyltrialkylammonium (chloride or methylsulfate),

8. The process for deinking of claim 1, wherein monomer (B) is in the form of a precursor selected from the group consisting of:
-vinyl pyridine or vinyl amines, -vinyl amides which can be subsequently quarternized with methyl chloride, benzyl chloride or dimethyl sulfate, -(meth)acrylic acid modified with glycidyltrialkylammomium chloride, - hydrolyzed vinyl formamide, and the inorganic salt or quarternized derivativesthereof.

9. The process for deinking of claim 1, wherein monomer (B) is of the formula:
HC=C(R3)-C(O)-N(R4,R5) in which R3 is H or C1 - C6, alkyl, R4 and R5 identical or different and are H or C1 - C12 hydrocarbon radicals.

10. The process for deinking of claim 2, wherein monomer (C) is of the formula:
H2C=C(R6)-C(O)-O-[CH2CH(R7)O]m-(CH2CH2O)n-R8 in which R6 is H or methyl; R7 is methyl; n is an average number from about 10 - 40 and m is an average number from about 0 -10, R8 is an hydrophobic C8 - C40 linear or branched alkyl, alkylaryl or arylalkyl group.

11. The process for deinking of claim 10, wherein R8 is a C18 - C30 alkyl radical

12. The process for deinking of claim 10, wherein R8 is a behenyl radical

13. The process for deinking of claim 10, wherein R8 is of the formula:
-O-[CH(CH3)-O]N
x is an average number of from about 2 to about 3, wherein the substituent denoted x is randomly distributed around the benzene ring to which it is linked.

14. The process for deinking of claim 1, wherein monomer (D) is of the formula:
R9CH=C(R10)COOH
in which R9 is H, C(O)OY or CH3, wherein when R9 is H, R10, is H, C1 - C4 alkyl, or CH2 COOY, when R9, is COOY, R10 is H or CH2COOY, or when R9 is CH3, R10 is H, Y is H or C1-C4 alkyl

15. The process for deinking of claim 1, wherein the amount of surface active copolymer (calculated as dry) ranges from about 0.01 to about 5.0 percent by weight based upon the dry weight of all wastepaper.

16. The process for deinking of claim 1, wherein monomer (D) is acrylic or methacrylic acid or a mixture thereof with itaconic or fumaric acid.

17. The process for deinking of claim 1, wherein the molecular weight of said surface active polymer is between 5,000 and 5,000,000 daltons.

18. The process for deinking of claim 1 wherein the ink is removed from the pulpby flotation, water washing or a combination of flotation and water washing.

19. The process according to claim 1 wherein the pH of said aqueous medium of step (2) is between about 4 to about 8.

20. The process according to claim 1 wherein the pH of said aqueous medium of step (2) is between about 8 to about 10.5.

21. The process according to claim 20 wherein the paper contains more than about50 % of oil-based inks.

22. The process according to claim 1 wherein said aqueous medium further comprises one or more nonionic surfactants selected from the group consisting of 1) a fatty alcohol having a carbon number of from about 8 to about 22, alkoxylated with ethylene oxide and propylene oxide, as represented by formula (1) R11-O-(CH2CH2O)8-(CH2CH(CH3)-O)y-Z1 (1), wherein R11 is a straight-chain or branched alkyl group having a carbon number of from about 8 to 22; Z1 is H or Cl; x represents the number of oxyethylene groups per molecule and is in the range of from about 3 to about 25; and y represents the number of oxypropylene groups per molecule and is in the range of from about 1 to about 10.

2) a fatty alcohol having a carbon number of from about 8 to about 22, alkoxylated with ethylene oxide and propylene oxide, as represented by formula (II):

R11-O-(CH2CH2O)x-(CH2CH(CH3)-O)y-(CH2CH2O)x-(CH2CH(CH3)-O)y-Z1(II);

wherein R11 is a straight-chain or branched alkyl group having a carbon number of from about 8 to about 22; Z1 is H or Cl; x and x', which may be the same or different, represents the number of oxyethylene groups per molecule and is in the range of trom about 2 to about 25; and y and y', which may be the same or different represents the number of oxypropylene groups per molecule and is in the range of from 0 to about 10 3) a fatty acid having a carbon number of from about 8 to about 22, alkoxylated with ethylene oxide and propylene oxide, as represented by formula (III):
R11-C(O)O-(CH2CH2O)x-(CH2CH(CH3)-O)y-Z1(III);
wherein R11 is a straight-chain or branched alkyl group having a carbon number of from about 8 to about 22; Z1 is H or Cl; x represents the number of oxyethylene groups per molecule and is in the range of from about 3 to about 25; and y represents the number of oxypropylene groups per molecule and is in the range of from about 2 to about 15.

4) an aromatic alcohol such as phenol having alkyl chain(s) with a carbon number of from about 8 to about 20, alkoxylated with ethylene oxide, as represented by formula (IV):

(R12)(R13).PHI. -(OCH2CH2)x-OZ1 (IV):

wherein .PHI. is a phenyl ring, R12 and R13 independently are H or an alkyl group which is branched or straight-chain having a carbon number of from about 8 to about 14, Z1 is H or Cl; and x is the number of oxyethylene groups per molecule and is in the range of from about 1 to about 20.

5) fatty amide of alkanolamide of formula (V):

;

wherein R' and R" may be the same or different and are H or CH2CH2OH or CH2CH(CH3)-OH and R11 is a fatty alkyl group having a carbon number of from about 8 to about 20 6) an alkoxylated fatty acid amide of alkanolamide of formula (VI):
R11-C(O)-N-(CH2CH2O)x-Z1 (CH2CH2O)x-Z1 (VI) wherein R11 is a fatty alkyl group having a carbon number of from about 8 to about 20; Z1 and Z1', which may be the same or different are H or Cl; and x and x', which may be the same or different, represents the number of oxyethylene groups per molecule and is in the range of from about 2 to about 10.
7) a propylene glycol alkoxylate of formula (VII) Z1O-(CH2CH2O)o(CH2CH(CH3)-O)m(CH2CH2O)p-Z1' (VII) wherein Z1 and Z1', which may be the same or different are H or Cl; o and p are the number of oxyethylene groups per molecule and are in the range of from about 3 to about 15 and m is the number of oxypropylene groups per molecule and is in the range of from about 5 to about 40 8) a block or random copolymer of ethylene and propylene oxide of formula (VIII):
Z1O(CH(CH3)CH2O)m(CH2CH2O)p(CH(CH3)CH2O)nZ1'(VIII) wherein Z1 and Z1' which may be the same or different are H or Cl; m and n are the number of oxypropylene groups per molecule and are in the range of from about 10 to about 25 and p is the number of oxyethylene groups per molecule and is in the range of from about 5 to about 25.

9) an ethoxylated fatty acid glycol and/or polyethylene glycol esters of formula (IX):
R15-C(O)O-(CH2CH2O)x-R16 (IX) wherein R15 is a fatty alkyl group of greater than C8, R16, is alkyl of greater than C8 or H; and x represents the number of oxyethylene groups per molecule and is in the range of trom about 5 to about 200.
Examples of commercially available products are Alkamus~ products sold by Rhône-Poulenc Inc. and products having a PEG castor oil CTFA designation; and 10) an ethoxylated fatty alcohol of formula (X):
R15O(CH2CH2O)x-Zl (X) wherein R15 is a fatty alkyl group; Zl is H or Cl; and x represents the number of oxyethylene groups per molecule and is in the range of from about 1 toabout 20.

23. The process according to claim 22 wherein said nonionic surfactant is present in step (2) in an amount of about 0.01 to about 3.0 percent by weight of the dry weight of all paper stock in step (1).

24. The process according to claim 1, wherein said steps (1) and (2) are performed at least partly at the same time