CA1330152C - Process for deinking printed waste paper - Google Patents
Process for deinking printed waste paperInfo
- Publication number
- CA1330152C CA1330152C CA 558004 CA558004A CA1330152C CA 1330152 C CA1330152 C CA 1330152C CA 558004 CA558004 CA 558004 CA 558004 A CA558004 A CA 558004A CA 1330152 C CA1330152 C CA 1330152C
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- Canada
- Prior art keywords
- weight
- solution
- earth metal
- alkaline earth
- metal salt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
- D21C5/02—Working-up waste paper
- D21C5/025—De-inking
- D21C5/027—Chemicals therefor
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Abstract
ABSTRACT OF THE DISCLOSURE
Process for deinking printed waste paper by treatment of the paper pulp in a pulper at alkaline pH values using alkali sili-cate, oxidative bleaches, higher fatty and/or resinic acids and dispersants and separation of the detached printing ink particles from the fiber suspension by flotation, the fatty and/or resinic acids being used in the form of their alkaline earth metal salts in fine distribution together with dispersants in an oil-in-water dispersion which is liquid at normal temperature.
Process for deinking printed waste paper by treatment of the paper pulp in a pulper at alkaline pH values using alkali sili-cate, oxidative bleaches, higher fatty and/or resinic acids and dispersants and separation of the detached printing ink particles from the fiber suspension by flotation, the fatty and/or resinic acids being used in the form of their alkaline earth metal salts in fine distribution together with dispersants in an oil-in-water dispersion which is liquid at normal temperature.
Description
PATENT
Case D 7811 PROCESS FOR DEINKING PRINTED WASTE PAPER
BACKGROUND OF THE INVENTION
1. Fleld of the Invent10n:
Thls ~nvent~on relates to a process for delnklng pr1nted waste paper by treatment of the paper pulp tn a pulper at alkal~ne pH values us~ng alkall metal silicate, oxidat~ve bleaches, higher `~
~atty actds alld/or reslnlc aclds and dlspersants and separatlon of - -~
the detached pr~ntlng lnk particles from the flber suspension by ;~ ; -lotatlon.
Case D 7811 PROCESS FOR DEINKING PRINTED WASTE PAPER
BACKGROUND OF THE INVENTION
1. Fleld of the Invent10n:
Thls ~nvent~on relates to a process for delnklng pr1nted waste paper by treatment of the paper pulp tn a pulper at alkal~ne pH values us~ng alkall metal silicate, oxidat~ve bleaches, higher `~
~atty actds alld/or reslnlc aclds and dlspersants and separatlon of - -~
the detached pr~ntlng lnk particles from the flber suspension by ;~ ; -lotatlon.
2. Statement o~ Related Art:
Delnk1ng comprlses the select1ve removal of prlntlng lnks from waste paper flber suspenslons. The reusable materlal thus ;
obtalned ls processed to end products, such as for example wrltlng `
paper, prlntlng paper, tollet paper, etc., dependlng on the par~
tlcular startlng mater1al.
Important steps ln the delnklng process are, flrst, the removal of the prlnt1ng lnks from the flbers ln a pulper uslng sultable chemlcals and, subsequently, thelr selectlve removal from - ~ ;
the flber suspenslon. Both ln flotatlon delnklng and ln washlng delnklng, these steps are carrled out ln alkallne medlum, the prlntlng lnks belng removed ln flotatlon cells or washers. The reuseable materlal obtalned ls then processed lnto the deslred products. ~ `-A typlcally used chemlcal formulatlon may have the followlng composltlon (quantltles based on the dry matter content of the ~ ~
,: . , ~.,, -1- ,,,~ .. . -. . ~. .
~ 1 330 1 52 waste paper~
0.5 to 2.0 X by welght alkall metal hydroxlde (100X) 0.2 to 1.5 X by welght soap or fatty acld (100X) 0.05 to 0.1 X by welght non10nlc dlspersant (lOOX) 2.0 to 5.0 X by welght alkall metal s111cate (waterglass) 0.1 to 0.3 X by welght dlethylenetrl~nlne pentacetlc acld, Na salt (D~PA) (40X) 0.5 to 3.0 X by welght oxldatlve bleach (100X).
The mech~nlsms by whlch the lndlvldual chemlcals act ln the ; flotatlon process are as follows:
Alkall metal hydroxlde, preferably sodlum hydroxlde, softens - -the flbers and hence facllltates breaklng up of the lnter-flber bonds and removal of the prlntlng lnk. Removal of the prlntlng m lnk ls addltlonally promoted by neutrallzatlon or saponlflcatlon of prlntlng lnk blnders. In addltlon, sodlum hydroxlde provldes ~ -the alkallnlty requlred to neutrallze tatty aclds whlch ls essen- ~-tlal to thelr functlon as collectors. ;~
Nonlonlc dlspers~nts lmprove wett1ng of the flbers by lowerlng the surface tenslon of the water, whlch pramotes~ lnter al1a, the effect of the other chemlcals, and ls largely responslble for the detachment of the prlntlng lnks and thelr dlsperslon. ~he ; d1sperslon of the prlntlng lnks prevents them from becomlng, or makes lt dlfflcult for them to become, reattached to the flbers. -,. . .
~; The detached plgments are hydrophoblclzed by the collectors, l.e. fatty ~clds or soaps, so that selectlve removal ls posslble.
~`~ In addltlon to the alkallne medlum, the salts responslble for the hardness of water are cruclally lmportant to thls functlon where known anlonlc collectors are used, bec~use lt ls only the calclum salts whlch hydrophoblclze the prlntlng lnk partlcles and thus make them floatable. Oxld~tlve bleaches prevent or campensate ~or ^~ the yellowlng of the wood-contalnlng waste paper ~nd, ln addltlon, also bleach tho flbers, dependlng on the dosage used. ~he bleaches are stablllzed by alkall met~l slllcate and D~P~ whleh, i' '~` 2 .
-by complex1ng the heavy metals, prevent overrapld decompos1t10n ot the bleach.
The waste paper used, depend1ng on the des1red end product, cons1sts of newspapers, magaz1nes, computer papers, f11es, etc., but 1n most cases m1xtures thereof, de1nkab111ty be1ng cruc1ally determ1ned by the pr1nt1ng 1nk systems used and the1r age.
Evaluat10n of the paper a~ter the de1nk1ng process 1s based on wh1teness measurement, the wh1teness of the test sheet be1ng compared w1th that of a standard (for example bar1um sulfate where whlteness 1s measured by the Elrepho system) and expressed ~n percent. For example, a waste paper mo1sture of da11y newspa-pers and magaz1nes 1n a ratlo of l:l glves a wh1teness of 56 to 1 60%, the whlteness of the unpr1nted marglns of these waste papers ¦ belng arpund 55 to 68X.
Prior published German application (DE-OS) 29 03 ~50 describes a process for de1nk1ng pr1nted waste paper by treatment of the paper pulp ln a pulper at alkallne pH values us1ng alkall s111cate, ox1-datlve bleaches, hlgher fatty aclds or salts thereof, and non10n1c d1spersants, w1th separat10n of the detached pr1nt1ng 1nk par- ~-t1cles from the f1ber suspenslon by flotat10n, a fatty ac1d alka-nolam1de add1tlonally belng used ln the pulper.
By contrast, German Patent 31 23 353 descrlbes a slmllar pro-cess whlch dlffers from the process dlsclosed ln DE-OS 29 03 150 ~ ~
flrstly ln that no fatty acld alkanolam1de 1s used 1n the pulper `~ -and secondly ln that the fatty ac1ds and/or reslnlc ac1ds and the dlspersants are added ln the form of an o11-ln-water emulslon. -However, these known processes are attended by certaln dlsadvantages. ~-~here sol1d fatty aclds are used as collectors, meltlng -apparatus or heated storage vessels are requlred where the fatty 5 aclds are supplled ln molten form.
There ls no need for heatlng where the fatty aclds used melt ; ~ ~
at temperatures below the normal temperature range, although fatty ;~-aclds such as these are generally attended by dlsadvantages ln terms of practlcal appllcatlon. ~ -.~. . . . : . ~ : ` , .. , ~ ' ~ ! ::~: ~ .: .
Under the react10n condlt10ns preva111ng ln the pulper, the relatlve1y h1gh melt1ng and 11quld fatty ac1ds sapon1fy only slowly, the soaps formed at the sur~ace o~ the ~atty ac1d par-tlcles compllcatlng or preventlng further saponlf1cat10n ot the enclosed fatty ac1ds. Not only does th1s result 1n a reduct10n 1n the collector effect, 1t can also lead to 1ntens1~1ed f1ber ~lota-t10n because the f1bers are hydrophob1c1zed by the unsapon1~1ed fatty ac1ds.
To overcome these d1sadvantages, the storage tanks used 1n the pr10r art are followed by sapon1~1catlon unlts. The resultlng aqueous soap solutlons thus have to be permanently tempered~
pend1ng process1ng because they form gels at normal temperature, 1.e. the 1ntermedlate storage vessels and also the meter1ng p1pes, lncludlng the meterlng head o~ the meterlng pumps, have to be heat-1nsulated and fully heated.
~here solld soaps are used, there ls no need for a saponlf1cat10n un1t. S1nce, 1n most cases, the soap granulates are not completely soluble under the process-dependent cond1tlons, dlssolv1ng un1ts have to be 1nstalled to prevent negat1ve effects. The result1ng soap solutlons are then attended by the same dlsadvantages as descrlbed above.
Another slgn1f1cant d1sadvantage attendlng known processes lles 1n the fact that the above-d1scussed format10n of calc1um soaps of the fatty ac1ds, wh1ch of course act as collectors, only takes place dur1ng the de1nk1ng process 1n the pulper w1th the hardness salts of the water used. The react10n t1me requ1red for th1s purpose thus extends the overall process t1me. In add1t10n, an lncomplete reactlon glves poorer delnklng results whlch are reflected, for example, ln reduced wh1teness levels. These d1sad-vantages also attend processes ln whlch the fatty aclds are used ln the fonm of an emulslon.
DESCRIPTION OF THE INVENTION
Other than ln the operatlng examples, or where otherw1se lndlcated, all numbers expresslng quantltles of lngred1ents or reactlon condltlons used hereln are to be understood as modlfled ln all lnstances by the term ~about~.
~_ :
- ' By contrast, an obJect of the present 1nvent10n 1s to prov1de an lmproved process ~or de1nklng prlnted waste paper wh1ch doçs not have any of the dlsadvantages dlscussed above and wh1ch, ln add1tlon, leads to better whlteness levels. More partlcularly, an ob~ect o~ the present lnvent10n 1s to develop a collector wh1ch enables sol1d fatty aclds to be used as collectors w1thout any need for melt1ng unlts or heated storage vessels.
Accord1ng to the 1nventlon, the obJects stated above are achleved by uslng the fatty ac1ds and/or res1ntc aclds ln the form of the1r alkaltne earth metal salts 1n f1ne d1strlbutlon together w1th dlspersants 1n an o11-1n-water d1spers10n wh1ch 1s llquld at normal temperatures.
Accordlngly, the present lnventlon relates to a process for de1nk1ng prlnted waste paper by (a) treatment of the paper pulp ln a pulper at alkallne pH values uslng alkall metal slllcate, oxldatlve bleaches, hlgher ~atty aclds and/or reslnlc ac1ds, d1spersants and (b) separat1cn of the detached pr1nt1ng lnk partlcles from the f1ber suspens10n by flotat10n, whereln the fatty ac1ds and/or res1n1c ac1ds are used 1n the form of the1r alkal1ne earth metal salts 1n f1ne d1strlbutlon together w1th d1spersants 1n an o11-1n-water d1sperslon wh1ch ls llquld at nonmdl temperatures.
Sultable alkallne earth metal salts of fatty aclds and/or resln1c aclds are, for example, the correspond1ng salts of magne-s1um, calclum, strontlum, or barlum, and m1xtures thereof.
; However, the fatty aclds and/or reslnlc aclds are preferably used ln the form of thelr calclu~ salts. Accordlngly, where reference ls made only to calclum salts 1n the follow1ng d1sclosure, 1t wlll be understood to also apply slmllarly to the other alkal1ne earth metal salts.
Accordlngly, the process of the 1nvent10n does not 1nvolve any reactlon tlme for reactlon wlth the alkall metal hydrox1de of ~, ~ . . , ~
.
:--` 1 330 1 5~
the chem1cal delnklng llquor and the hardness salts o- the water, whlch was essentlal to the functlon of the hltherto used anlonlc collectors based on fatty ac1ds or soaps. Accordlngly, the pro-cess of the 1n~entlon also enables soft water to be used. The very flne dlstrlbutlon of the calclum salts and thelr product-speclflc propertles guarantee an excellent collector effect whlch ls reflected, lnter alla, ln lmproved whlteness levels.
The oll-ln-water dlsperslons of calclum salts of the fatty and/or reslnlc aclds can be dlrectly lntroduced, l.e. wlthout any pretreatment, from the storage tank lnto the delnklng process at any polnt because a reactlon ls no longer necessary, so that the collector functlon ls spontaneously performed. Accordlngly, no dlsadvantages arlse even where pulplng ls carried out ln the hlgh-conslstency range at pulp densltles of 15 to 20X. Introductlon lmmedlately before the delnklng unlt ls also posslble wlthout any dlsadvantages.
By vlrture of thelr lncreased surface actlvlty, the oll-ln-water dlsperslons of calclum salts of the fatty and/or reslnlc aclds provlde for excellent detachment and collectlon of the prlntlng lnk partlcles.
The llpophlllc resldue of the calclum salts o- the fatty and/or reslnlc ac1ds can conslst of Cg-C22 alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl radlcals whlch may be llnear, branched, even-numbered, odd-numbered or condensed-polycycllc.
Mlxtures of the above calclum salts of fatty and/or reslnlc aclds can also be used. C12-Clg groups are preferred. Examples of fatty and/or reslnlc aclds sultable for use ln accordance wlth the lnventlon are C12-C18 fatty aclds elther lndlvldually or ln admlxture, tallow fat b acld, palm oll fatty acld, synthetlc fatty aclds havlng acld values of l90 to 200, abletlc acld, and, ln ¦ partlcular, C12-Clg anlmal fatty aclds.
, ~here ~normal temperature~ ls mentloned ln connectlon wlth the o/w dlsperslon, thls ls understood to lnclude typlcal amblent ' or room temperatures whlch may extend for e~ample from ~4 to ~30C. The delnklng process ltself ls preferably carrled out at temperDtures of 40 to 50C. The o/w dlsperslons are of course also llquld at temperatures ln that range.
:
' ' ~ ,. ' A '~ ~ ~
1330~52 The calc1um salts o~ the fatty or res1n1c ac1ds are present 1n the o/w d1spers10n 1n the f1ne d1str1but10n wh1ch ls typ1cal of, or requ1red for, stable o/w d1spers10ns.
011-1n-water d1spers10ns hav1ng a sol1ds content ot 10 to 50X
by we1ght, based on the d1spers10n as a whole, are preferably used for the purposes of the 1nvent10n. Sol1ds contents of 35 to 40X
by we1ght, based on the d1spers10n as a whole, are part1cularly preferred.
In another preferred embod1ment of the 1nvent10n, 1n the o11-1n-water d1spers10ns from 70 to 90X by we1ght of the above s011ds content 1s the calc1um salt of the fatty and/or res1n1c ac1ds.
The o11-1n-water dlspers10ns used 1n accordance w1th the 1nvent10n also conta1n non10n1c and/or an10n1c d1spersants.
Preferred are nonlonlc d1spersants wh1ch are added to the d1sper-slons durln!a the1r preparat10n. The non10n1c and/or an10n1c dlspersants are preferably used 1n a quant1ty of 1 to 40X by we1ght, based on the calc1um salts of the fatty and/or res1n1c ac1ds. ~here an10n1c d1spersants are used, they are normally used ln a quant1ty of 1 to lOX by we1ght, based on the calctu~ salts of 20 the fatty and/or reslnlc acld ln the dlsperslon.
Sultable nonlonlc d1spersants are, for example, alkylpolyglycol ethers, 1soalkyl pol " lycol ethers, hydroxyalkyl polyglycol ethers, alkenyl pol " lytol ethers, alkylaryl polygly-col ethers, acyl pol " lycol esters and polyoxyethylene glycerol 25 fatty acld esters, ln each case contalnlng 8 to 22 carbon atoms ln the hydrocarbon radtcal and 6 to 30 mol-s of ethylene oxlde.
Sultable anlonlc dlspersants ar-, for example, alkyl sulfona-tes, alkylaryl sulfonates, alkyl sulfates, alkyl pol " lycol ether sulfates, alkylaryl polyglycol ether sulfates and proteln fatty ~ ac1d condensates. The ethylene oxlde content of the alkyl polyglycol ether sulfates and alkylaryl polyglycol ether sulfates ls from 2 to 25 moles. These anlonlc dlspersants contaln C8-C22 hydrocarbon radlcals. The anlonlc dlspersants are nonTally used ln the fonn of the1r alkal1 metal and/or amlne salts.
, ', ' To prepare the oll-ln-water dlsperslons sultablo ~or uso ln accordance wlth the lnventlon, lt ls ot advantage to react the fatty and/or res1nlc aclds wlth a stolchlometrlc excess o-calclum, pre~erably ln the ~orm of calclum hydrox1de, ln aqueous solutlon alkal1zed w1th sodlum hydroxlde, sultable nonlon1c and/or an10n1c d1spersants be1ng added to the solut10ns betorehand.
In one part1cular embod1ment o~ the present 1nventlon, the process ~or delnklng prlnted waste paper ls carr1ed out by us1ng a comblnat10n o- the ollow1ng components ln the pulper (~) 0.5 to 2 X by we1ght sod1um hydrox1de (lOOX);
(b) 2 to 5 X by we1ght alkal1 metal sll1cate;
(c) 0.1 to 0.3 X by we1ght d1ethylenetr1am1ne pentaacetlc acld, sod1um salt (DTPA) (40X aqueous solutlon);
(d) 0.5 to 3 X by we1ght o- an ox1dat1ve bleach, e.g. hydrogen perox1de (lOOX);
(e) 0.2 to 1.5 X by welght oll-ln-water dlsperslon o~ tatty acld and/or res1nlc ac1d calc1um salts;
(f) O to O.5X by we1ght non10n1c d1spersants, these quantttles all belng based on the quantlty of waste paper used.
In general, commerclal waterglass solutlons (soda and/or potash waterglasses) are used as the alkall metal slllcates (component b). Soda watergl~sses ln whlch the ratlo by welght o-S102 to Na20 ls 3.3:1 are pre-erred. The oll-1n-water d1sperslons used correspond to the crlterla set ~orth above.
In addltlon to the dlspersants whlch are present ln the o/w dlsperslons, other nonlonlc dlspersants (component ~) ~ay optlon~lly be used ln the process. The oregolng descrlptlon o~
the nonlonlc dlspers~nts used ln prep~rlng the o/w dlsperslons apply s1m11arly to the b pe o- nonlonlc d1spersants whlch may be addlttonally used. It ls pre~erred to use ~rom O.OS to O.lX by welght nonlon1c d1spersants, aga1n based on waste paper; more especlally Ca-C22 alkyl pol " lycol ethers and/or Cg-C22 acyl polyglycol esters, ln each case w1th 6 to 30 moles of ethylene oxlde.
The lnventlon ls lllustrated but not llmlted by the ~ollowlng Examples.
,i ~ , ~, ", `, " ~", ~
EXAMPLES
100 9 bone-dry (110 9 a1r-dry) prlnted waste paper cons1st1ng of 100X da11y newspapers were 1ntroduced 1nto 1890 ml of an aqueous chem1cal delnk1ng 11quor and pulped for 15 mlnutes at around 45C uslng a dlspers10n d1sc (2500 r.p.m.). The hardness of the water used was approx1mately 17Gh.
The chemlcals used and thelr concentrat10ns were as follows, based 1n each case on the dry matter content of the waste paper:
1.0 X sod1um hydrox1de (lOOX) 3.0 % soda waterglass (rat10 by we1ght S102 to Na20 3.3:1) 0.2 X DTPA (commerc1al product, 40 X) 0.85 X hydrogen perox1de (lOOX) 0.7 X collector The part1cular compos1t10n of the ~collector~ was varled and can be seen from the follow1ng Examples accord1ng to the 1nvent10n and from the Compar1son Examples.
The react10n t1me after pulp1ng was 2 h, correspond1ng to the swell1ng t~me 1n the vats.
The 5X pulp suspenslon was then made up to 4000 ml wlth water haYlng a hardness of approx1mately 17Gh and de1nked for 5 m1nutes In a laboratory flotatlon cell, the delnked pulp suspenslon was made up w1th water havlng the above hardness to the le~el of the froth overflow of the cell and subsequently floated for 10 m1nutes, the level be~ng kept at the he13ht of the froth overflow by addltlon of water.
; The resultlng reuseable materlal was then thlckened to a pulp denslty of approx1mately 20X.
The thlckened reuseable mater1al was dlluted to a pulp den-slty of approx1mately 4X by add1tlon of 800 ml water havlng a hardness of approxlmately 17Gh, pulped and acldlfled to pH 6 wlth dllute sulfurlc acld.
100 9 of thls pulp suspenslon were then made wlth water to 500 ml, produclng a p~ulp denslty of approxlmately 0.8X, and f~ltered under suctton through ~ fllter paper (t 12 cm).
The sheet thus formed was drled after smoothlng.
~h~teness was measured wlth an Elrepho R 45t.
_9_ J~l~ *Trade Mark ` 1330152 , The procedure was as descr1bed above uslng as collector 0.7X
by welght of a c~lclum salt dlsperslon ot whlch the composltlon was as tollows:
60 parts anlmal C12-Clg tatty acld 12 parts Clg alkyl polyglycol ether - 20 E0 1.5 part sodlum hydroxlde 8.6 parts calclum hydroxlde 123.5 parts water whlteness: 59.1X.
The procedure was as descrlbed above uslng ~s collector 0.7X
by we~ght of a calclum salt dlsperslon ot whlch the composltlon was as follows:
60 parts anlmal C12-Clg tat b acld ~ -9 parts Clg alkyl polyglycol ether - 20 E0 3 parts abletlc acld polyglcyol ester - 85X E0 (based on abletlc acld) -~
1.5 parts sodlum hydroxlde :
8.6 parts calclum hydroxlde 123.5 parts water whlteness: 5S.OX
The procedure was as descrlbed above uslng as collector 0.7X
: by welght o~ a calclum salt dlsperslon of whlch the composltlon was as tollo~s:
-.
60 parts anlmal C12-Clg fatty acld 9 parts Clg alkyl polyglycol ether - 20 E0 3 parts polyoxyethylene glycerol C16-Clg tatty acld ester- 20 E0 : :~
1.5 parts sodlum hydroxlde ! --10--`, 1330152 : -:
.
8.6 parts calclum hydrox1de -~
123.5 parts water wh1teness: 59.QX.
The procedure was as descr1bed above us1ng as collector 0.7X
by we1ght of a calc1um salt d1spers10n of wh1ch the compos1t10n was as follows:
60 parts an1mal C12-Clg fatty ac1d 9 parts Clg alkyl polyglycol ether - 20 E0 3 parts C12-Clg alkyl sulfonate, Ha salt ¦ 1.5 parts sod1um hydroxlde 1 8.6 parts calc1um hydrox1de 123.5 parts water whlteness: 58.0X
2Q ~he procedure was as descr1bed above us1ng as collector 0.7X -by welght of a calc1um salt d1spers10n of wh1ch the compos1t10n was as follows:
.~: ' 60 parts an1mal Cl2-Clg fatty ac1d 9 parts Clg alkyl polyglycol ether - 20 E0 : -3 parts C12 alkyl sultate, Nh salt ; 1.5 parts sodlum hydroxlde 8.6 parts calclum hydroxlde : 123.5 parts water whlteness: 58.1X
EXAMPLE 6 - -~
. - . .
The procedure was as descrlbed above us1ng as collector 0.7X
. 35 by welght of a calclum salt dlspers10n of wh1ch the composltlon was as ~ollows:
, :,' - : .,, parts tallow fatty acld 12 parts C1g alkyl polyglycol ether - 20 EO
1.5 parts sodlum hydrox1de 8.6 parts calclum hydrox1de 123.5 parts water whlteness: 59.lX
The procedure was as descrlbed above uslng as collector 0.7X
by welght of a calclum salt dlsperslon of whlch the composltlon was as follows:
parts synthetlc fatty acld lacld value 190 - 200) 12 parts C1g alkyl polyglycol ether - 20 EO
1.5 parts sod1um hydroxlde 8.6 parts calclum hydroxlde -123.5 parts water whlteness: 59.9X
The procedur- was as descrlbed above uslng as collector 0.7X
by welght of a commerclal delnklng soap (sodlum soap of C1o-C~g fatty aclds).
whlteness: 57.4X
CO~PARISON EXAMPLE 2 -The procedure was as descrlbed above uslng as collector 0.7X by -~
welght of a commerclal emulslon of fatty aclds and/or reslnlc aclds contalnlng more than 10 carbon atoms.
whlteness: 55.9X Y -~
As the Comparlson Examples correspondlng to the prlor art show, cons1derably better whlteness values are obta1ned where the process 1s c~rr1ed out 1n accordance w1th the 1nvent10n, tak1ng 1nto ~ccount the fact that, 1n pract1ce, an 1ncrease 1n wh1teness of only lX represents a cons1derable 1mprovement. ~n other words, thc process carr1ed out 1n accord~nce w1th the pr10r art g1ves overall poorer de1nk1ng results for the same process t1me. By contrast, 1mmed1ate, select1ve ~lotat10n occurs 1n the process ~ccord1ng to the 1nvent10n, wh1ch 1s also reflected 1n the h1gher wh1teness v~lues.
,~ ~
.- ,.~, ..
....
. ,, , ~
~ ~ .
. .~ , , . .- . ... . . .
Delnk1ng comprlses the select1ve removal of prlntlng lnks from waste paper flber suspenslons. The reusable materlal thus ;
obtalned ls processed to end products, such as for example wrltlng `
paper, prlntlng paper, tollet paper, etc., dependlng on the par~
tlcular startlng mater1al.
Important steps ln the delnklng process are, flrst, the removal of the prlnt1ng lnks from the flbers ln a pulper uslng sultable chemlcals and, subsequently, thelr selectlve removal from - ~ ;
the flber suspenslon. Both ln flotatlon delnklng and ln washlng delnklng, these steps are carrled out ln alkallne medlum, the prlntlng lnks belng removed ln flotatlon cells or washers. The reuseable materlal obtalned ls then processed lnto the deslred products. ~ `-A typlcally used chemlcal formulatlon may have the followlng composltlon (quantltles based on the dry matter content of the ~ ~
,: . , ~.,, -1- ,,,~ .. . -. . ~. .
~ 1 330 1 52 waste paper~
0.5 to 2.0 X by welght alkall metal hydroxlde (100X) 0.2 to 1.5 X by welght soap or fatty acld (100X) 0.05 to 0.1 X by welght non10nlc dlspersant (lOOX) 2.0 to 5.0 X by welght alkall metal s111cate (waterglass) 0.1 to 0.3 X by welght dlethylenetrl~nlne pentacetlc acld, Na salt (D~PA) (40X) 0.5 to 3.0 X by welght oxldatlve bleach (100X).
The mech~nlsms by whlch the lndlvldual chemlcals act ln the ; flotatlon process are as follows:
Alkall metal hydroxlde, preferably sodlum hydroxlde, softens - -the flbers and hence facllltates breaklng up of the lnter-flber bonds and removal of the prlntlng lnk. Removal of the prlntlng m lnk ls addltlonally promoted by neutrallzatlon or saponlflcatlon of prlntlng lnk blnders. In addltlon, sodlum hydroxlde provldes ~ -the alkallnlty requlred to neutrallze tatty aclds whlch ls essen- ~-tlal to thelr functlon as collectors. ;~
Nonlonlc dlspers~nts lmprove wett1ng of the flbers by lowerlng the surface tenslon of the water, whlch pramotes~ lnter al1a, the effect of the other chemlcals, and ls largely responslble for the detachment of the prlntlng lnks and thelr dlsperslon. ~he ; d1sperslon of the prlntlng lnks prevents them from becomlng, or makes lt dlfflcult for them to become, reattached to the flbers. -,. . .
~; The detached plgments are hydrophoblclzed by the collectors, l.e. fatty ~clds or soaps, so that selectlve removal ls posslble.
~`~ In addltlon to the alkallne medlum, the salts responslble for the hardness of water are cruclally lmportant to thls functlon where known anlonlc collectors are used, bec~use lt ls only the calclum salts whlch hydrophoblclze the prlntlng lnk partlcles and thus make them floatable. Oxld~tlve bleaches prevent or campensate ~or ^~ the yellowlng of the wood-contalnlng waste paper ~nd, ln addltlon, also bleach tho flbers, dependlng on the dosage used. ~he bleaches are stablllzed by alkall met~l slllcate and D~P~ whleh, i' '~` 2 .
-by complex1ng the heavy metals, prevent overrapld decompos1t10n ot the bleach.
The waste paper used, depend1ng on the des1red end product, cons1sts of newspapers, magaz1nes, computer papers, f11es, etc., but 1n most cases m1xtures thereof, de1nkab111ty be1ng cruc1ally determ1ned by the pr1nt1ng 1nk systems used and the1r age.
Evaluat10n of the paper a~ter the de1nk1ng process 1s based on wh1teness measurement, the wh1teness of the test sheet be1ng compared w1th that of a standard (for example bar1um sulfate where whlteness 1s measured by the Elrepho system) and expressed ~n percent. For example, a waste paper mo1sture of da11y newspa-pers and magaz1nes 1n a ratlo of l:l glves a wh1teness of 56 to 1 60%, the whlteness of the unpr1nted marglns of these waste papers ¦ belng arpund 55 to 68X.
Prior published German application (DE-OS) 29 03 ~50 describes a process for de1nk1ng pr1nted waste paper by treatment of the paper pulp ln a pulper at alkallne pH values us1ng alkall s111cate, ox1-datlve bleaches, hlgher fatty aclds or salts thereof, and non10n1c d1spersants, w1th separat10n of the detached pr1nt1ng 1nk par- ~-t1cles from the f1ber suspenslon by flotat10n, a fatty ac1d alka-nolam1de add1tlonally belng used ln the pulper.
By contrast, German Patent 31 23 353 descrlbes a slmllar pro-cess whlch dlffers from the process dlsclosed ln DE-OS 29 03 150 ~ ~
flrstly ln that no fatty acld alkanolam1de 1s used 1n the pulper `~ -and secondly ln that the fatty ac1ds and/or reslnlc ac1ds and the dlspersants are added ln the form of an o11-ln-water emulslon. -However, these known processes are attended by certaln dlsadvantages. ~-~here sol1d fatty aclds are used as collectors, meltlng -apparatus or heated storage vessels are requlred where the fatty 5 aclds are supplled ln molten form.
There ls no need for heatlng where the fatty aclds used melt ; ~ ~
at temperatures below the normal temperature range, although fatty ;~-aclds such as these are generally attended by dlsadvantages ln terms of practlcal appllcatlon. ~ -.~. . . . : . ~ : ` , .. , ~ ' ~ ! ::~: ~ .: .
Under the react10n condlt10ns preva111ng ln the pulper, the relatlve1y h1gh melt1ng and 11quld fatty ac1ds sapon1fy only slowly, the soaps formed at the sur~ace o~ the ~atty ac1d par-tlcles compllcatlng or preventlng further saponlf1cat10n ot the enclosed fatty ac1ds. Not only does th1s result 1n a reduct10n 1n the collector effect, 1t can also lead to 1ntens1~1ed f1ber ~lota-t10n because the f1bers are hydrophob1c1zed by the unsapon1~1ed fatty ac1ds.
To overcome these d1sadvantages, the storage tanks used 1n the pr10r art are followed by sapon1~1catlon unlts. The resultlng aqueous soap solutlons thus have to be permanently tempered~
pend1ng process1ng because they form gels at normal temperature, 1.e. the 1ntermedlate storage vessels and also the meter1ng p1pes, lncludlng the meterlng head o~ the meterlng pumps, have to be heat-1nsulated and fully heated.
~here solld soaps are used, there ls no need for a saponlf1cat10n un1t. S1nce, 1n most cases, the soap granulates are not completely soluble under the process-dependent cond1tlons, dlssolv1ng un1ts have to be 1nstalled to prevent negat1ve effects. The result1ng soap solutlons are then attended by the same dlsadvantages as descrlbed above.
Another slgn1f1cant d1sadvantage attendlng known processes lles 1n the fact that the above-d1scussed format10n of calc1um soaps of the fatty ac1ds, wh1ch of course act as collectors, only takes place dur1ng the de1nk1ng process 1n the pulper w1th the hardness salts of the water used. The react10n t1me requ1red for th1s purpose thus extends the overall process t1me. In add1t10n, an lncomplete reactlon glves poorer delnklng results whlch are reflected, for example, ln reduced wh1teness levels. These d1sad-vantages also attend processes ln whlch the fatty aclds are used ln the fonm of an emulslon.
DESCRIPTION OF THE INVENTION
Other than ln the operatlng examples, or where otherw1se lndlcated, all numbers expresslng quantltles of lngred1ents or reactlon condltlons used hereln are to be understood as modlfled ln all lnstances by the term ~about~.
~_ :
- ' By contrast, an obJect of the present 1nvent10n 1s to prov1de an lmproved process ~or de1nklng prlnted waste paper wh1ch doçs not have any of the dlsadvantages dlscussed above and wh1ch, ln add1tlon, leads to better whlteness levels. More partlcularly, an ob~ect o~ the present lnvent10n 1s to develop a collector wh1ch enables sol1d fatty aclds to be used as collectors w1thout any need for melt1ng unlts or heated storage vessels.
Accord1ng to the 1nventlon, the obJects stated above are achleved by uslng the fatty ac1ds and/or res1ntc aclds ln the form of the1r alkaltne earth metal salts 1n f1ne d1strlbutlon together w1th dlspersants 1n an o11-1n-water d1spers10n wh1ch 1s llquld at normal temperatures.
Accordlngly, the present lnventlon relates to a process for de1nk1ng prlnted waste paper by (a) treatment of the paper pulp ln a pulper at alkallne pH values uslng alkall metal slllcate, oxldatlve bleaches, hlgher ~atty aclds and/or reslnlc ac1ds, d1spersants and (b) separat1cn of the detached pr1nt1ng lnk partlcles from the f1ber suspens10n by flotat10n, whereln the fatty ac1ds and/or res1n1c ac1ds are used 1n the form of the1r alkal1ne earth metal salts 1n f1ne d1strlbutlon together w1th d1spersants 1n an o11-1n-water d1sperslon wh1ch ls llquld at nonmdl temperatures.
Sultable alkallne earth metal salts of fatty aclds and/or resln1c aclds are, for example, the correspond1ng salts of magne-s1um, calclum, strontlum, or barlum, and m1xtures thereof.
; However, the fatty aclds and/or reslnlc aclds are preferably used ln the form of thelr calclu~ salts. Accordlngly, where reference ls made only to calclum salts 1n the follow1ng d1sclosure, 1t wlll be understood to also apply slmllarly to the other alkal1ne earth metal salts.
Accordlngly, the process of the 1nvent10n does not 1nvolve any reactlon tlme for reactlon wlth the alkall metal hydrox1de of ~, ~ . . , ~
.
:--` 1 330 1 5~
the chem1cal delnklng llquor and the hardness salts o- the water, whlch was essentlal to the functlon of the hltherto used anlonlc collectors based on fatty ac1ds or soaps. Accordlngly, the pro-cess of the 1n~entlon also enables soft water to be used. The very flne dlstrlbutlon of the calclum salts and thelr product-speclflc propertles guarantee an excellent collector effect whlch ls reflected, lnter alla, ln lmproved whlteness levels.
The oll-ln-water dlsperslons of calclum salts of the fatty and/or reslnlc aclds can be dlrectly lntroduced, l.e. wlthout any pretreatment, from the storage tank lnto the delnklng process at any polnt because a reactlon ls no longer necessary, so that the collector functlon ls spontaneously performed. Accordlngly, no dlsadvantages arlse even where pulplng ls carried out ln the hlgh-conslstency range at pulp densltles of 15 to 20X. Introductlon lmmedlately before the delnklng unlt ls also posslble wlthout any dlsadvantages.
By vlrture of thelr lncreased surface actlvlty, the oll-ln-water dlsperslons of calclum salts of the fatty and/or reslnlc aclds provlde for excellent detachment and collectlon of the prlntlng lnk partlcles.
The llpophlllc resldue of the calclum salts o- the fatty and/or reslnlc ac1ds can conslst of Cg-C22 alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl radlcals whlch may be llnear, branched, even-numbered, odd-numbered or condensed-polycycllc.
Mlxtures of the above calclum salts of fatty and/or reslnlc aclds can also be used. C12-Clg groups are preferred. Examples of fatty and/or reslnlc aclds sultable for use ln accordance wlth the lnventlon are C12-C18 fatty aclds elther lndlvldually or ln admlxture, tallow fat b acld, palm oll fatty acld, synthetlc fatty aclds havlng acld values of l90 to 200, abletlc acld, and, ln ¦ partlcular, C12-Clg anlmal fatty aclds.
, ~here ~normal temperature~ ls mentloned ln connectlon wlth the o/w dlsperslon, thls ls understood to lnclude typlcal amblent ' or room temperatures whlch may extend for e~ample from ~4 to ~30C. The delnklng process ltself ls preferably carrled out at temperDtures of 40 to 50C. The o/w dlsperslons are of course also llquld at temperatures ln that range.
:
' ' ~ ,. ' A '~ ~ ~
1330~52 The calc1um salts o~ the fatty or res1n1c ac1ds are present 1n the o/w d1spers10n 1n the f1ne d1str1but10n wh1ch ls typ1cal of, or requ1red for, stable o/w d1spers10ns.
011-1n-water d1spers10ns hav1ng a sol1ds content ot 10 to 50X
by we1ght, based on the d1spers10n as a whole, are preferably used for the purposes of the 1nvent10n. Sol1ds contents of 35 to 40X
by we1ght, based on the d1spers10n as a whole, are part1cularly preferred.
In another preferred embod1ment of the 1nvent10n, 1n the o11-1n-water d1spers10ns from 70 to 90X by we1ght of the above s011ds content 1s the calc1um salt of the fatty and/or res1n1c ac1ds.
The o11-1n-water dlspers10ns used 1n accordance w1th the 1nvent10n also conta1n non10n1c and/or an10n1c d1spersants.
Preferred are nonlonlc d1spersants wh1ch are added to the d1sper-slons durln!a the1r preparat10n. The non10n1c and/or an10n1c dlspersants are preferably used 1n a quant1ty of 1 to 40X by we1ght, based on the calc1um salts of the fatty and/or res1n1c ac1ds. ~here an10n1c d1spersants are used, they are normally used ln a quant1ty of 1 to lOX by we1ght, based on the calctu~ salts of 20 the fatty and/or reslnlc acld ln the dlsperslon.
Sultable nonlonlc d1spersants are, for example, alkylpolyglycol ethers, 1soalkyl pol " lycol ethers, hydroxyalkyl polyglycol ethers, alkenyl pol " lytol ethers, alkylaryl polygly-col ethers, acyl pol " lycol esters and polyoxyethylene glycerol 25 fatty acld esters, ln each case contalnlng 8 to 22 carbon atoms ln the hydrocarbon radtcal and 6 to 30 mol-s of ethylene oxlde.
Sultable anlonlc dlspersants ar-, for example, alkyl sulfona-tes, alkylaryl sulfonates, alkyl sulfates, alkyl pol " lycol ether sulfates, alkylaryl polyglycol ether sulfates and proteln fatty ~ ac1d condensates. The ethylene oxlde content of the alkyl polyglycol ether sulfates and alkylaryl polyglycol ether sulfates ls from 2 to 25 moles. These anlonlc dlspersants contaln C8-C22 hydrocarbon radlcals. The anlonlc dlspersants are nonTally used ln the fonn of the1r alkal1 metal and/or amlne salts.
, ', ' To prepare the oll-ln-water dlsperslons sultablo ~or uso ln accordance wlth the lnventlon, lt ls ot advantage to react the fatty and/or res1nlc aclds wlth a stolchlometrlc excess o-calclum, pre~erably ln the ~orm of calclum hydrox1de, ln aqueous solutlon alkal1zed w1th sodlum hydroxlde, sultable nonlon1c and/or an10n1c d1spersants be1ng added to the solut10ns betorehand.
In one part1cular embod1ment o~ the present 1nventlon, the process ~or delnklng prlnted waste paper ls carr1ed out by us1ng a comblnat10n o- the ollow1ng components ln the pulper (~) 0.5 to 2 X by we1ght sod1um hydrox1de (lOOX);
(b) 2 to 5 X by we1ght alkal1 metal sll1cate;
(c) 0.1 to 0.3 X by we1ght d1ethylenetr1am1ne pentaacetlc acld, sod1um salt (DTPA) (40X aqueous solutlon);
(d) 0.5 to 3 X by we1ght o- an ox1dat1ve bleach, e.g. hydrogen perox1de (lOOX);
(e) 0.2 to 1.5 X by welght oll-ln-water dlsperslon o~ tatty acld and/or res1nlc ac1d calc1um salts;
(f) O to O.5X by we1ght non10n1c d1spersants, these quantttles all belng based on the quantlty of waste paper used.
In general, commerclal waterglass solutlons (soda and/or potash waterglasses) are used as the alkall metal slllcates (component b). Soda watergl~sses ln whlch the ratlo by welght o-S102 to Na20 ls 3.3:1 are pre-erred. The oll-1n-water d1sperslons used correspond to the crlterla set ~orth above.
In addltlon to the dlspersants whlch are present ln the o/w dlsperslons, other nonlonlc dlspersants (component ~) ~ay optlon~lly be used ln the process. The oregolng descrlptlon o~
the nonlonlc dlspers~nts used ln prep~rlng the o/w dlsperslons apply s1m11arly to the b pe o- nonlonlc d1spersants whlch may be addlttonally used. It ls pre~erred to use ~rom O.OS to O.lX by welght nonlon1c d1spersants, aga1n based on waste paper; more especlally Ca-C22 alkyl pol " lycol ethers and/or Cg-C22 acyl polyglycol esters, ln each case w1th 6 to 30 moles of ethylene oxlde.
The lnventlon ls lllustrated but not llmlted by the ~ollowlng Examples.
,i ~ , ~, ", `, " ~", ~
EXAMPLES
100 9 bone-dry (110 9 a1r-dry) prlnted waste paper cons1st1ng of 100X da11y newspapers were 1ntroduced 1nto 1890 ml of an aqueous chem1cal delnk1ng 11quor and pulped for 15 mlnutes at around 45C uslng a dlspers10n d1sc (2500 r.p.m.). The hardness of the water used was approx1mately 17Gh.
The chemlcals used and thelr concentrat10ns were as follows, based 1n each case on the dry matter content of the waste paper:
1.0 X sod1um hydrox1de (lOOX) 3.0 % soda waterglass (rat10 by we1ght S102 to Na20 3.3:1) 0.2 X DTPA (commerc1al product, 40 X) 0.85 X hydrogen perox1de (lOOX) 0.7 X collector The part1cular compos1t10n of the ~collector~ was varled and can be seen from the follow1ng Examples accord1ng to the 1nvent10n and from the Compar1son Examples.
The react10n t1me after pulp1ng was 2 h, correspond1ng to the swell1ng t~me 1n the vats.
The 5X pulp suspenslon was then made up to 4000 ml wlth water haYlng a hardness of approx1mately 17Gh and de1nked for 5 m1nutes In a laboratory flotatlon cell, the delnked pulp suspenslon was made up w1th water havlng the above hardness to the le~el of the froth overflow of the cell and subsequently floated for 10 m1nutes, the level be~ng kept at the he13ht of the froth overflow by addltlon of water.
; The resultlng reuseable materlal was then thlckened to a pulp denslty of approx1mately 20X.
The thlckened reuseable mater1al was dlluted to a pulp den-slty of approx1mately 4X by add1tlon of 800 ml water havlng a hardness of approxlmately 17Gh, pulped and acldlfled to pH 6 wlth dllute sulfurlc acld.
100 9 of thls pulp suspenslon were then made wlth water to 500 ml, produclng a p~ulp denslty of approxlmately 0.8X, and f~ltered under suctton through ~ fllter paper (t 12 cm).
The sheet thus formed was drled after smoothlng.
~h~teness was measured wlth an Elrepho R 45t.
_9_ J~l~ *Trade Mark ` 1330152 , The procedure was as descr1bed above uslng as collector 0.7X
by welght of a c~lclum salt dlsperslon ot whlch the composltlon was as tollows:
60 parts anlmal C12-Clg tatty acld 12 parts Clg alkyl polyglycol ether - 20 E0 1.5 part sodlum hydroxlde 8.6 parts calclum hydroxlde 123.5 parts water whlteness: 59.1X.
The procedure was as descrlbed above uslng ~s collector 0.7X
by we~ght of a calclum salt dlsperslon ot whlch the composltlon was as follows:
60 parts anlmal C12-Clg tat b acld ~ -9 parts Clg alkyl polyglycol ether - 20 E0 3 parts abletlc acld polyglcyol ester - 85X E0 (based on abletlc acld) -~
1.5 parts sodlum hydroxlde :
8.6 parts calclum hydroxlde 123.5 parts water whlteness: 5S.OX
The procedure was as descrlbed above uslng as collector 0.7X
: by welght o~ a calclum salt dlsperslon of whlch the composltlon was as tollo~s:
-.
60 parts anlmal C12-Clg fatty acld 9 parts Clg alkyl polyglycol ether - 20 E0 3 parts polyoxyethylene glycerol C16-Clg tatty acld ester- 20 E0 : :~
1.5 parts sodlum hydroxlde ! --10--`, 1330152 : -:
.
8.6 parts calclum hydrox1de -~
123.5 parts water wh1teness: 59.QX.
The procedure was as descr1bed above us1ng as collector 0.7X
by we1ght of a calc1um salt d1spers10n of wh1ch the compos1t10n was as follows:
60 parts an1mal C12-Clg fatty ac1d 9 parts Clg alkyl polyglycol ether - 20 E0 3 parts C12-Clg alkyl sulfonate, Ha salt ¦ 1.5 parts sod1um hydroxlde 1 8.6 parts calc1um hydrox1de 123.5 parts water whlteness: 58.0X
2Q ~he procedure was as descr1bed above us1ng as collector 0.7X -by welght of a calc1um salt d1spers10n of wh1ch the compos1t10n was as follows:
.~: ' 60 parts an1mal Cl2-Clg fatty ac1d 9 parts Clg alkyl polyglycol ether - 20 E0 : -3 parts C12 alkyl sultate, Nh salt ; 1.5 parts sodlum hydroxlde 8.6 parts calclum hydroxlde : 123.5 parts water whlteness: 58.1X
EXAMPLE 6 - -~
. - . .
The procedure was as descrlbed above us1ng as collector 0.7X
. 35 by welght of a calclum salt dlspers10n of wh1ch the composltlon was as ~ollows:
, :,' - : .,, parts tallow fatty acld 12 parts C1g alkyl polyglycol ether - 20 EO
1.5 parts sodlum hydrox1de 8.6 parts calclum hydrox1de 123.5 parts water whlteness: 59.lX
The procedure was as descrlbed above uslng as collector 0.7X
by welght of a calclum salt dlsperslon of whlch the composltlon was as follows:
parts synthetlc fatty acld lacld value 190 - 200) 12 parts C1g alkyl polyglycol ether - 20 EO
1.5 parts sod1um hydroxlde 8.6 parts calclum hydroxlde -123.5 parts water whlteness: 59.9X
The procedur- was as descrlbed above uslng as collector 0.7X
by welght of a commerclal delnklng soap (sodlum soap of C1o-C~g fatty aclds).
whlteness: 57.4X
CO~PARISON EXAMPLE 2 -The procedure was as descrlbed above uslng as collector 0.7X by -~
welght of a commerclal emulslon of fatty aclds and/or reslnlc aclds contalnlng more than 10 carbon atoms.
whlteness: 55.9X Y -~
As the Comparlson Examples correspondlng to the prlor art show, cons1derably better whlteness values are obta1ned where the process 1s c~rr1ed out 1n accordance w1th the 1nvent10n, tak1ng 1nto ~ccount the fact that, 1n pract1ce, an 1ncrease 1n wh1teness of only lX represents a cons1derable 1mprovement. ~n other words, thc process carr1ed out 1n accord~nce w1th the pr10r art g1ves overall poorer de1nk1ng results for the same process t1me. By contrast, 1mmed1ate, select1ve ~lotat10n occurs 1n the process ~ccord1ng to the 1nvent10n, wh1ch 1s also reflected 1n the h1gher wh1teness v~lues.
,~ ~
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....
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Claims (25)
1. In a process for deinking printing waste paper pulp by treatment of the pulp with an alkaline solution containing an alkali metal silicate, an oxidative bleach, a dispersant, and either a higher fatty acid, a resinic acid or a mixture thereof, followed by separation of the resulting detached printing ink particles from the pulp fiber suspension by flotation, the improvement wherein the higher fatty acid, resinic acid, or mixture thereof is added to the solution in the form of a finely divided alkaline earth metal salt in an oil-in-water dispersion which is liquid at room temperatures.
2. The process of Claim 1 wherein the oil-in-water dispersion also contains a dispersant.
3. The process of Claim 1 wherein the alkaline earth metal salt is the calcium salt.
4. The process of Claim 2 wherein the alkaline earth metal salt comprises a hydrophilic group and a lipophilic group, and the lipophilic group of the alkaline earth metal salt is a C8-C22 alkyl, alkenyl, hydroxyalkyl, hydroxyalkenyl, or mixture of two or more of such groups.
5. The process of Claim 4 wherein the groups are linear, branched, condensed polycyclic, or mixtures thereof.
6. The process of Claim 4 wherein the lipophilic group is a C12-C18 group.
7. The process of Claim 1 wherein the oil-in-water dispersion has a solids content of from about 10 to about 50% by weight.
8. The process of Claim 7 wherein the solids content is from about 35 to about 40% by weight.
9. The process of Claim 7 wherein from about 70 to about 90% by weight of the solids content is a calcium salt of a higher fatty acid, a resinic acid, or a mixture thereof.
10. The process of Claim 7 wherein the oil-in-water dispersion contains from about 1 to about 40% by weight of either a nonionic. dispersant, an anionic dispersant, or a mixture of such dispersants, based on the weight of the alkaline earth metal salt.
11. The process of Claim 2 wherein the dispersant is a nonionic dispersant in the oil-in-water dispersion which is one or more of an alkyl polyglycol ether, an isoalkyl polyglycol ether, an hydroxyalkyl polyglycol ether, an alkenyl polyglycol ether, an alkylaryl polyglycol ether, an acyl polyglycol ester, and a polyoxyethylene glycerol fatty acid ester, each of which contains from 8 to 22 carbons in the hydrocarbon radical and from 6 to 30 moles of ethylene oxide.
12. The process of Claim 2 wherein the dispersant in the oil-in-water dispersion is an anionic dispersant which is one or more of an alkyl sulfonate, an alkylaryl sulfonate, an alkyl sulfate, an alkyl polyglycol ether sulfate containing 2 to 25 moles of ethylene oxide, an alkylaryl polyglycol ether sulfate containing 2 to 25 moles of ethylene oxide, and a protein fatty acid condensate, each of which contains from 8 to 22 carbon atoms in the hydrocarbon radical, and each of which is present in the form of its alkali metal salt, its amine salt, or a mixture of such salts.
13. An aqueous alkaline solution for deinking printed waste paper pulp comprising (a) from about 0.5 to about 2 % by weight of sodium hydroxide (100%), (b) from about 2 to about 5 % by weight of an alkali metal silicate, (c) from about 0.1 to about 0.3 % by weight of diethyl-enetriamine pentaacetic acid, sodium salt (40% aqueous solution), (d) from about 0.5 to about 3% by weight of an oxidative bleach (100%), (e) from about 0.2 to about 1.5% by weight of an oil-in-water dispersion, liquid at room temperature, of a finely divided alkaline earth metal salt of a higher fatty acid, resinic acid, or mixture thereof, and (f) from 0 to about 0.5% by weight of nonionic dispersants, the percentages by weight based on the weight of the waste paper being deinked.
14. The solution of claim 13 wherein the oxidative bleach is hydrogen peroxide.
15. The solution of claim 13 wherein from about 0.5 to about 0.1% by weight of component (f) is present.
16. The solution of claim 15 wherein component (f) is a C8-C22 alkyl polyglycol ether and/or a C8-C22 acyl polyglycol ester, each of which contains from 6 to 30 moles of ethylene oxide.
17. The solution of claim 13 wherein component (e) also contains a dispersant.
18. The solution of claim 13 wherein in component (e) the alkaline earth metal salt comprises a hydrophilic group and a lypophilic group and the lipophilic group of the alkaline earth metal salt is C8-C22 alkyl, alkenyl, hydroxyalkyl, or hydroxyalkenyl group, or a mixture of two or more of such groups.
19. The solution of claim 18 wherein the groups are linear, branched, condensed polycyclic or mixtures thereof.
20. The solution of claim 18 wherein the lipophilic group is a C12-C18 group.
21. The solution of claim 13 wherein the oil-in-water dispersion of component (e) has a solids content of from about 10 to about 50% by weight.
22. The solution of claim 21 wherein the solids content is from about 35 to about 40% by weight.
23. The solution of claim 21 wherein from about 70 to about 90%
by weight of the solids content is said alkaline earth metal salt.
by weight of the solids content is said alkaline earth metal salt.
24. The solution of claim 21 wherein the oil-in-water dispersion contains from about 1 to about 40% by weight of a nonionic and/or anionic dispersant, based on the weight of the alkaline earth metal salt.
25. The solution of claim 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 or 24 wherein in component (e), the alkaline earth metal salt is the calcium salt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3702978.9 | 1987-02-02 | ||
| DE3702978A DE3702978C1 (en) | 1987-02-02 | 1987-02-02 | Process for de-inking printed waste paper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1330152C true CA1330152C (en) | 1994-06-14 |
Family
ID=6320005
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 558004 Expired - Fee Related CA1330152C (en) | 1987-02-02 | 1988-02-02 | Process for deinking printed waste paper |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4959123A (en) |
| EP (1) | EP0277570B1 (en) |
| JP (1) | JPS63196789A (en) |
| AT (1) | ATE78306T1 (en) |
| CA (1) | CA1330152C (en) |
| DE (2) | DE3702978C1 (en) |
| DK (1) | DK167698B1 (en) |
| ES (1) | ES2033943T3 (en) |
| FI (1) | FI85727C (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3811025A1 (en) * | 1988-03-31 | 1989-10-12 | Gruenau Gmbh Chem Fab | METHOD FOR DE-INKING PRINTED WASTE PAPER |
| DE3934893A1 (en) * | 1989-10-19 | 1991-04-25 | Gruenau Gmbh Chem Fab | WAFER, ERDALKALISEIFEN AND / OR EARTHALKALIHARSE SOAPS CONTAINING DISPERSIONS FOR DEFINING PRINTED ALTPAPERS |
| US5158697A (en) * | 1989-10-26 | 1992-10-27 | Harima Chemicals, Inc. | Deinking agent for reproduction of printed waste papers |
| JPH064947B2 (en) * | 1989-12-22 | 1994-01-19 | 花王株式会社 | Deinking agent for recycled waste paper |
| US5171427A (en) * | 1990-02-23 | 1992-12-15 | The Dow Chemical Company | Sulfonated and carboxylate collector compositions useful in the flotation of minerals |
| FR2664627B1 (en) * | 1990-07-12 | 1995-11-24 | Tech Ind Papiers C Centre | PROCESS FOR INKING PRINTED PAPERS. |
| AU653772B2 (en) * | 1990-12-17 | 1994-10-13 | Dow Chemical Company, The | Aryl monosulfonate collectors useful in the flotation of minerals |
| NZ242280A (en) * | 1991-04-25 | 1994-02-25 | Betz Int | De-inking electrostatically printed paper using a surfactant in an aqueous |
| US5248388A (en) * | 1991-04-25 | 1993-09-28 | Betz Paperchem, Inc. | Use of surfactants having an HLB less than 10 in the deinking of dry toner electrostatic printed wastepaper |
| US5200034A (en) * | 1991-04-25 | 1993-04-06 | Betz Paperchem, Inc. | Use of surfactants having an HLB less than 10 in the deinking of dry toner electrostatic printed wastepaper |
| CA2082557C (en) * | 1992-02-24 | 1997-03-11 | Charles W. Hankins | Integrated pulping process of waste paper yielding tissue-grade paper fibers |
| US5314580A (en) * | 1992-07-08 | 1994-05-24 | Mauvin Material & Chemical Processing Limited | Process for the removal of ink, resin, and adhesive residues from paper, textile fabrics and solid surfaces |
| US5500082A (en) * | 1993-04-26 | 1996-03-19 | North Carolina State University | Deinking of xerographic printed wastepaper using long chain alcohol |
| US5415733A (en) * | 1993-05-27 | 1995-05-16 | High Point Chemical Corp. | Method of removing hydrophilic ink |
| US5417807A (en) * | 1993-05-27 | 1995-05-23 | Kao Corporation | Deinking formulation for flexographic inks |
| US5518581A (en) * | 1993-06-04 | 1996-05-21 | Nicca Chemical Co., Ltd. | Deinking agent for regeneration of waste paper |
| CA2099070A1 (en) * | 1993-06-23 | 1994-12-24 | Nelson Mak | Process and apparatus for deinking wastepaper with molten fatty acid |
| JPH10501898A (en) * | 1994-05-27 | 1998-02-17 | ジ・ユニバーシティ・オブ・アクロン | Non-birefringent optical adhesive and thin film |
| JP2992210B2 (en) | 1994-10-20 | 1999-12-20 | 花王株式会社 | Deinking agent for recycled paper |
| GR1002461B (en) * | 1995-12-29 | 1996-11-01 | Industrial exploitation of waste materials with complete material recycling and optimisation of product's and energy generation. | |
| JP3051826B2 (en) | 1996-06-03 | 2000-06-12 | 花王株式会社 | Deinking method |
| US6784146B1 (en) * | 2000-10-27 | 2004-08-31 | Kemira Chemicals, Inc. | Deinking method and composition for wastepaper |
| AU2002215296A1 (en) * | 2000-12-21 | 2002-07-01 | Akzo Nobel N.V. | Solid composition for de-inking of recycling paper |
| US20020121347A1 (en) * | 2000-12-21 | 2002-09-05 | Akzo Nobel N.V. | Chemical composition and process |
| US6666950B2 (en) | 2001-11-28 | 2003-12-23 | Basf Ag | Process for deinking paper using a triglyceride |
| US7433948B2 (en) * | 2002-01-23 | 2008-10-07 | Cisco Technology, Inc. | Methods and apparatus for implementing virtualization of storage within a storage area network |
| US20050116382A1 (en) * | 2002-07-12 | 2005-06-02 | Philippe Nusbaum | Closure device comprising a hinged cap moulded in the closed position |
| DE10254862A1 (en) * | 2002-11-25 | 2004-06-03 | Degussa Ag | Process for decolourization of printing ink from waste paper by flotation thinking |
| US7169257B2 (en) * | 2003-11-12 | 2007-01-30 | Kemira Chemicals, Inc. | Method of deinking waste paper using a reduced alkali system |
| US8133350B2 (en) | 2008-07-09 | 2012-03-13 | Nalco Company | Deinking a cellulosic substrate using magnesium silicate |
| US20100006244A1 (en) * | 2008-07-09 | 2010-01-14 | Duggirala Prasad Y | Deinking a cellulosic substrate using an inorganic mineral |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2903150A1 (en) * | 1979-01-27 | 1980-08-07 | Henkel Kgaa | METHOD FOR THINKING PRINTED WASTE PAPER |
| DE2941783A1 (en) * | 1979-10-16 | 1981-04-30 | Hoechst Ag, 6000 Frankfurt | FLOTATION AGENT FOR REMOVING PIGMENTS FROM WASTE PAPER |
| DE3123353C2 (en) * | 1981-06-12 | 1984-09-13 | Akzo Gmbh, 5600 Wuppertal | Process for deinking printed waste paper |
| DE3144387A1 (en) * | 1981-11-07 | 1983-05-19 | J.M. Voith Gmbh, 7920 Heidenheim | Method of processing wastepaper suspensions by flotation |
-
1987
- 1987-02-02 DE DE3702978A patent/DE3702978C1/en not_active Expired
-
1988
- 1988-01-25 AT AT88101000T patent/ATE78306T1/en not_active IP Right Cessation
- 1988-01-25 DE DE8888101000T patent/DE3872724D1/en not_active Expired - Lifetime
- 1988-01-25 ES ES88101000T patent/ES2033943T3/en not_active Expired - Lifetime
- 1988-01-25 EP EP19880101000 patent/EP0277570B1/en not_active Expired - Lifetime
- 1988-01-29 DK DK046488A patent/DK167698B1/en not_active IP Right Cessation
- 1988-02-01 FI FI880435A patent/FI85727C/en not_active IP Right Cessation
- 1988-02-02 CA CA 558004 patent/CA1330152C/en not_active Expired - Fee Related
- 1988-02-02 JP JP63024855A patent/JPS63196789A/en active Pending
- 1988-02-02 US US07/151,387 patent/US4959123A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ES2033943T3 (en) | 1993-04-01 |
| DK46488D0 (en) | 1988-01-29 |
| ATE78306T1 (en) | 1992-08-15 |
| FI85727C (en) | 1992-05-25 |
| DE3702978C1 (en) | 1988-06-30 |
| FI85727B (en) | 1992-02-14 |
| FI880435A (en) | 1988-08-03 |
| DE3872724D1 (en) | 1992-08-20 |
| EP0277570A2 (en) | 1988-08-10 |
| JPS63196789A (en) | 1988-08-15 |
| FI880435A0 (en) | 1988-02-01 |
| EP0277570A3 (en) | 1989-01-25 |
| EP0277570B1 (en) | 1992-07-15 |
| DK46488A (en) | 1988-08-03 |
| DK167698B1 (en) | 1993-12-06 |
| US4959123A (en) | 1990-09-25 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |