CA2030540A1 - Production of paper, board and cardboard in the presence of copolymers containing n-vinylformamide units - Google Patents
Production of paper, board and cardboard in the presence of copolymers containing n-vinylformamide unitsInfo
- Publication number
- CA2030540A1 CA2030540A1 CA002030540A CA2030540A CA2030540A1 CA 2030540 A1 CA2030540 A1 CA 2030540A1 CA 002030540 A CA002030540 A CA 002030540A CA 2030540 A CA2030540 A CA 2030540A CA 2030540 A1 CA2030540 A1 CA 2030540A1
- Authority
- CA
- Canada
- Prior art keywords
- paper
- weight
- copolymer
- vinylformamide
- copolymers
- 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.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/06—Paper forming aids
- D21H21/10—Retention agents or drainage improvers
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
- D21H17/45—Nitrogen-containing groups
- D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
Abstract
Abstract of the Disclosure: Paper, board and cardboard are produced by draining a paper stock in the presence of a nonhydrolyzed copolymer which contains, as polymerized units, a) from 99 to 1 mol % of N-vinylformamide and (b) from 1 to 99 mol % of one or more water-soluble basic monomers of the formula (I) or (II) where R1 is H, CH3 or C2H5, R2, R3 and R4 are each H, CH3, C2H5 or (-CH2-CH2-O-)nH, R5 and R6 are each C1-C10-alkyl, A
is C1-C6-alkylene, n is from 1 to 6 and Y6 is an anion, in an amount of from 0.01 to 3.5% by weight, based on dry paper stock.
is C1-C6-alkylene, n is from 1 to 6 and Y6 is an anion, in an amount of from 0.01 to 3.5% by weight, based on dry paper stock.
Description
2 ~ 0 -~ O.Z. 0050/40659 Production of_paper board and cardboard in the presence sf copolymers containin N-vinylformamide units The present invention relates to a process for ~he production of paper, board and cardboard by draining a paper stock in the presence of copolymers containing N-vinylformamide unit~.
JP-A-118 406/86 discloses water-soluble poly-vinylamines which are prepared by polymerizing N-vinyl-formamide or mixtures of N-vinylformamide with other water-soluble monomers, such as acrylamide, N,N-dialkyl-acrylamide~ or diallyldialkylammonium ~alts and subse-quently hydrolyzing the polymers with bases, eg. ethyl-i~mine, diethylamine, ethylenediamine or morpholine. ~he polyvinylamine~ are used as drainage aids and rekention aids in papermaking and as flocculant~ for wastewaters.
U.S. Patent 4,421,602 di~closes polymers which are obtainable by partial hydrolysis of polyl-N-vinyl-formamide with acids or bases. As a result of the hydrolysi~, these polymers contain ~inylamine and N-vinylformamide units. They are u~ed, for example inpapermaking, as drainage aids, flocculants and retention aids.
EP-A-0 220 603 discloses, inter alia, that N-vinylformamide can be subjectecl to copolymerization together with basic acrylates, such as dimethylaminoethyl acrylate, or N-vinylimidazoline~, in ~upercritical carbon dioxide. The resulting finely divided copolymers are -~sed in the partially hydrolyzed form, in which ~hey contain vinylamine unit~, for example a~ retention aids and flocculants in papermaXing.
EP-A-0 282 761 disclose~ a proce~s for the production of paper, ~oard and cardboard having high dry ctrength, in which the dry ~trength agent used is a mixture of cationic polymers, which may also contain, ~mong typical monomer~, pol~merized unit~ of vinylamine, and natural potato ~tarch, the potato starch baing converted into a water-soluble form by heating in an ;';"
`
2~3~
- ; - 2 - O.Z. 0050/40659 aqueous medium in the presence of a cationic polymer to tPmperatures above the gela~inization temperature of natural potato starch in the absence o~ oxidizing agents, polymerization initiator~ and alkali.
It is an ob~ec~ of the present invention to provide papermaking assistants which ideally are more effective than the conventional ones and which are technically more readily available.
We have found that this objec~ is achieYed, according to the invention, by a process for the produc-tion of paper, board and cardboard by draining a paper stocX in the presence of ~ polymex containing N-vinyl-formamide units, if a nonhydrolyzed copolymer which contains, as polymerized units, (a) from 99 to 1 mol % of N-vinylformamide and (b) from 1 to 99 mol % of one or more water-soluble basic monomer~ of the formula CH 2=C ~ ~A~ R 3 ye ( I ) or O R~' CH 2=CH--CH 2~i,CH ~C~=CH 2 ye R ~ R6 (II) where Rl is H, CHs or C2H5, R2, R3 and R4 are each H, CH3, C2Hs or (-CH2-CH2-O-)nH, Rs and R6 are each Cl-C1O-alkyl, A
is Cl-C~-alkylene~ n i~ from 1 to 6 and ye is an anion, i~
used in an amount of from 0.01 to 3.5~ by weight, based on dry paper stock, as the polymer containing N-~inyl-formamide units.
~ he ~dvantage of the nonhydroly2ed copolymerscontaining N-vinylformamide uni~ over the previously u~ed hydrolyzed copol~mers which contain vinylamine units a~ter the hydrolysis i8 that the hydrolysis, which is di~ficult to carry out in many cases, is dispensed with and effective papermaking assistants are obtainable by direct copolymerization.
. A ~uitable mo~omer (a) of the copolymers is : ' 2~ 0 ~` - 3 - O.Z. 0050/40659 N-vinylformamide. This monomer is present in the copoly-mers in an amount of from 1 to 99, preferably from 60 to 95, mol %.
Suitable monomers of group (b) are the compounds of the formula I, of which the following compounds may be stated by way of examples N-tximethyl-N-tacrylamidoethyl)-ammonium chloride, N-trimethyl-N-(methacrylamidoethyl)-a~monium chloride, N-trimethyl-N-(acrylamidoethyl3-ammonium methosul~ate, N trimethyl-N-(methacxylamidoethyl)-ammonium metho-sulfate, N-ethyldimethyl-N-(methacrylamidomethyl)-ammonium etho-~ul~ate, N-ethyldimethyl N (acrylamidomethyl)-ammonium etho-sulfate, N-trimethyl-N-(acrylamidopropyl)-ammonium chloride, N-trimethyl-N-(methac~ylamidopropyl)-ammonium chloride, ~;
N-trimethyl-N-(acrylamidopropyl)-ammonium methosulfate, ~ ~`
N-trimethyl-N-(methacrylamidopropyl)-ammonium metho-sulate, N-ethyldimethyl-N-(methacrylamidopropyl)-ammonium etho-sulfate and N-ethyldimethyl-N-(acrylamidopropyl)-ammonium eth~sulfate.
N-Trimethyl-N-(methacryl~midopropyl)-ammonium ~ ~ -chloride is pxeferred.
Other suitable monomers of group (b) are the compounds o~ th~ formula II. Example~ o~ compounds of this type are diallyldimethylammonium chloride, diallyl-dimethylammonium bromide, diallyldiethylammoniumchloride and diallyldiethylammonium bromide. Diallyldimethyl-ammonium chloride i8 preferably used. The anion ye is an acid radical and is preferably chloride, bromide, iodide, sulfate, metho~ulfate or ethosulfate.
Among the monomers of group (b), the compounds of the formula I or II may be present in the copolymers ~;
either alone or as a mixture with one another. It is , 2~3~0 - 4 - O.Z. 0050/40659 al~o possible to use a plurality of compounds of the formula I or II in the copolymerization of the monomer (a). The monomers of group (b) are pre6ent in the copolymers in an amount of from 99 to l, preferably from 4 0 to 5, mol %.
The copol~meriæa~ion of the monomers (a) and (b) is carried out in aqueou~ ~olution in the pre~ence of polymerization initiators which decompose into free radical~ under the polymerization conditions. ~xamples of suitable polymerization initiators are hydrogen peroxide, alkali metal and ammonium salt~ of peroxy-disulfuric acid, pero~ides, hydroperoxides~ redox cata-lyst~ and in particular nonoxidizing initiators, such as azo compounds which decompose into free radicals. Water-æoluble azo compound~, such as 2,2'-azobi~-(2-amidino-propane) dihydrochloride, 2,2~-azobis-(N,N'-dimethylene-isobutyramidine~ dihydrochloride or 2,2' azobi~-[2~
methyl-N-(2-hydroxyethyl~-propionamide], are preferably u~ed. The polymerization initiators are employed in conventional amount~, for example in amount~ of from 0.01 to 5% by weight, based on the monomers to be polymerized.
Polymerization can be carried out in a wide temperature range9 under atmospheric pres~ure, reduced or super-atmospheric pres3ure, in appropriately de~igned apparatuse~. The polymerization is preferably effected under atmospheric pres~ure and at not more than 100C, in par~icular from 30 to 80C. The concentration of the mono~ers in the agueou~ solution i~ preferably cho3en to give polymex ~olutions who~e solids content i8 from 10 to 90, prefer~bly from 20 to 70, % ~y weight. ~he pH of the reaction mixture i8 brought to 4-10, preferably 5-8.
Depending on the polymexization condition~
copolymers having different moleclllar weights are ob-tained~ To characterize a copolymer, the R value accord-ing to H. Fikent~cher i~ ~tated instead of tha molecular weight. The ~ values (measured in 5% strength aqueous ~odium chloride solution at 2SC and at a polymer ' , ', :
2 ~
- - 5 - O.Z. 0050/40659 concèntration of 0.1% by weight) are from 5 to 350.
Copolymers having low molecular weights and corres-pondingly low X values axe obtained by the conventional methods, ie. the use of relatively large amounts of 5peroxide in the copolymerization or ~he use of poly-merization regulators or combinations of the two measures stated. Polymers having a high K value and high mole-cular weights are obtained, for example, by polymerizing the monomers by reverse ~uspension polymerization or by 10polymPrizing monomers (a) and (b) by the water-in~oil polymerization process. In the reverse suspen~ion polymerization proce3s and in water-in-oil polymeriza-tion~ saturated hydrocarbons, for example hexane, heptane, cyclohexane or decalin, or aromatic hydro-15carbons, such as benzene, toluene, ~ylene or c~mene, are used a,s the oil phase. The ratio of oil phase to aqueous pha~e in reverse suspension polymerization is, for example, from 10 : 1 to 1 : 10, preferably from 7 : 1 to 1: 1.
20In order to disperse the aqueous monomer solution in an inert hydrophobic liquid, a protecti~e colloid is required, the purpo~e of which is to stabilLze the suspension of the aqueous monomer 301ution in the inert hydrophobic liquid. The protective colloids furthermore 25affect the particle size of the polymer beads formed by polymeri~ation.
Examples of suitable protective colloids are the ~ub~tances described in U.S. Patent 2,982,749. The protective colloids which are disclosed in German Patent 302,634,486 and are ob~ainablet for example, by reacting oils and/or resins, each of which have allyl hydrogen atoms, with maleic anhydride are also suitable. Other ~uitable protective colloids are disclosed in, for example, German Patent 2,710,372 and are obtainable by 35thermal or ~ree radical solution or mass polymerization from 60-99.9% by weight of dicyclopentadiene, 0-30% by weight of styrene and 0.1-10% by weight of maleic ' '; ',, , , ' "~'~ "' 2~3~4~
~ - 6 - r~.z. 0050/40659 .
anhydride.
Other suitable protective colloids are graft pol~mers which are obtainable by grafting polymers (a) of a3 from ~0 to 100% by weight of monovinylaromatic monomers, b) from 0 to 60% by weight of monoethylenically un~
saturated carboxylic acids of 3 to 6 carbon atoms, maleic anhydride ~,nd/or itaconic anhydride and c) from 0 to 20% by weight of other monoethylenically : :
unsaturated monomers, ::
with the proviso that the sum of the percentages by : ~:
weight (a) to (c) i~ always 100 and the polymers (A) have ~ -:
a number average molecular weight of from 500 to 20,000 : -~
and a hydrogenation iodine number (according to DIN
53,241) of fxom 1.3 to Sl, with monomer mixtures of ;~
1) from 70 to 100% by weight of acrylates and/or ::.
methacrylates of monohydric alcohols of 1 to 20 .;~
carbon atoms, 2) from 0 to 15~ by weight of monoethylenically un~
sa~ura~ed carboxylic acids of 3 to 6 carbon atoms, : ~ .
maleic anhydride and~or itaconic anhydride, ~ ~:
: 3) from 0 to 10% by weight o~ acrylic monoesters and/or methacrylic monoesters of at least dihydric alcohols, -:: .
4) from 0 to 15% by weight of monovinylaromatic mono-mers and S) from 0 to 7.5% by weight of acrylamide and/or methacrylamide, with the proviso that the sum of the percentages by w~ight a) to e) i8 always 100, :
at not more than 150C in an ~nert hydrophobic diluent in the presence of polymerization initiators, the monomers being u~ed in an amount of from 97.5 to 50% by weight, ;:~
based on the mixture of polymer ~A) and monomers.
Protective colloids of this typs are described in :~
EP-A-0290 753.
When an aliphatic hydrocarbon is used as the inert hydrophobic liquid in the reverse suspension 2 03 ~ ~ 4 ~
- 7 - O.Z. 0050/40659 polymerization, a mixture of an inorganic suspending agent based on modified finely divided minerals and a nonionic surfactant has proven very advantageous as the protective colloid.
The inorganic suspending agents, which have a low hydrophilic/lyophilic balance, are the agents usually employed in reverse suspension polymerization processes.
The mineral component of thPse substances is, for ex-ample, bentonite, montmorillonite or kaolin. Finely divided minerals are modified by being treated with salts of long-chain amines, for example C8-C24-amines, or quaternary ammonium salts, th~ amine salts or the quater-nary ammonium salts being intercalated between the individual layers of the finely divided minerals. The quaternized ammonium ~alt~ which may be used for modific-ation preferably contain 1 or 2 C10-C22-alkyl radicals.
The other ubstituents of the ammonium sal~s are Cl-C4-alkyl or hydrogen. The content of free ammonium salts of the amine modified mineral~ is no~ more than 2% by weight. Finely divided minerals modified with ammonium salts are commercially available.
~ha inorganic suspending a~ents for reverse suspension polymerization include silica which has been reacted with organosilicon compounds. Æ suitable organo-silicon compound i~, for example, trimethylsilyl chloride.
The purpoqie of the modification of the inorganic ~inely divided minerals is to improve the wettability of the minerals with the aliphatic hydrocarbon used as the outer phase of the re~erse suspension polymerization. In the case of the na~ural mineral~ having a layer-like structure, for example bentonite and montmorillonite, the re3ult of modification with amines i~ that the modified minerals swell in the aliphatic hydrocarbon and thus disintegrate into very ~ine particles. The particle size is about 1 ~m, in general from O.S to 5 ~m. The silicas reacted with organosilicon compounds have a particle size .. , . . , , ~ ., ~ .,.
' . " ;'.' '' ' ''' ' ' ' ; ''" '; ' ' ' ,"' ,- ' ' ,, ' 2~3~0 -- 8 - O.Z. 0050/40659 o~ about 10-40 nm. The modified finely divided minerals are wetted both by the aqueous monomer solution and the - -solvent and thus accumulate in the phase interface be~ween the aqueous phase and the organic phase. They -;
prevent coagulation on collision of two aqueous monomer ~ -droplets in the suspension.
After the end of the copolymerization, some of ~-the water is distilled azeotropically so that copolymers having a solids content of from 70 to 99, preferably from 80 to 95, % by weight are obtained. The copolymers are in the form of fine bead~ having a diameter of from 0.05 to 1 mm.
In contrast to the prior art, the copolymers deZ3cribed above are used in nonhydrolyzed form as an additi~e to the paper stock in the production Qf paper, board and cardboard. These copolymerZ3 contain no ~inyl-amine uni~s. They increase ~he rate of drainage of the paper stock, 80 that the production speed in papermaking can be incxeased. The copolymers ~lso act as retention aids for fib~rs and fillerZ3 and simultaneously as floc-culants. To achieve the stated effects, the copolymers are added to the paper stock in ~nountZs of from 0.01 to about 0.8% by weight, based on dry paper stock. Using larger ~mounts of copolymers impartZ3 dry ætrength. In order to achieve such effectZ3, the polymerZ~ are used in amounts of about 0.5-3.5ZZ~ by weight, hased on dry paper 3tock. The uZ~e of the stated copolymers to~ether with natural potato starch as dry strength agents is par-ticularly preferred. Such mixtures have good retention for paper fibers in tha paper stock. The COD of the white water i8 con iderably reduced by mean~ of these mixtures compared with natural starch. ~he troublesom substanceZ3 present in the wator circulationZ3 of paper machines hava only a slight adverZ3e ~ffect on the e~fici-ency of the mixtures of the copolymers to be used accord-ing to the invention and natural Z~tarch. The pH of the paper stock suspension may he ~rom 4 to 9, preferably ,~, '. ,, ,'.:
~03~5~
- - 9 - O.Z. 0050/40659 from 6 to 8.5. These mixtures of natural starch and cationic polymer which are added to the paper stock for imparting dry strength are preferably prepared by heating natural pota~o starch in the presence of the non-hydrolyzed copolymers in aqueous solution to temperaturesabove the gelatinization temperature of the natural potato starch, in the absence of oxidizing agents, polymerization initiators and alkali. The natural potato s~arch is modified in this manner.
The gelatinization temperature of the starch is the temperature at which the birefringence of the starch particles is lost (cf. Ullmanns ~nzyklopadie der technis-chen Chemie, Urban und Schwarzenberg, Munich-Berlin, 1965, 16th volume~ page 322).
Modification of the natural potato starch can be carried out in various ways. A digested natural potato starch which i8 in the form of an aqueous ~olution can be reacted with the suitabla cationic polymers at from 15 ~o 70C. At even lower temperatures~ longer contact times are required. If the r~action is carried out at even higher temperatures, for example up to 110C, shorter contact times, eg. from 0.1 to 15 minutes, are required.
The simplest method of modifying natural potato starch is to heat an aqueous suspension of the starch in the presence of the suitable cationic copolymer~ to above the gelati~ization temperature of ~he natural potato starch.
Por modiication, the ~tarch i~ generally heated to 70-llO~C, the reaction being carried out in pressure~resist~
ant apparatu~es at above 110C. However, it is also pos3ible fir~t to heat an aqueous suspension o~ natural potato ~tarch to 70~110C and to bring the starch into ~olution and then to add the cationic copolymer required for modification. Solubilizing of the starch is carried out in the absence o~ oxidizing agents, initiators and alkali, in the course of about 3 minute~ to 5 hour~, pre~erably from 5 to 30 minute~. Higher temperature~
require a ~horter residence time here.
' :
~ 0 3 0 3 4 ~ :
- - 10 - O.Z. 0050/40659 From 1 to 20, preferably from 8 to 12, parts by weight of a single sui~able nonhydrolyzed cationic copolymer or of a mixture o such copolymer~ are used per 100 parts by weight of natural potato starch. As a result of the reaction with the cationic copolymers, the natural potato starch is con~erted into a water-soluble form. The vi~cosity of the aqueou~ phase of the reaction mixture increases. A 3.5% strength by weight aqueous solution of the dry strength agent has viscosities of 10from 50 to 10,000 mPa.s (measured according to Brookfield at 20 rpm and 20C).
The copolymers to be used according to the invention can be employed in the production of all known paper, cardboard and board grades, for example for the 15production of writing, printing and packaging papers.
The papers may be produced from a large number of dif-ferent fiber materials, for example from bleached or unbleached sul~ite or ~iulfate pulp, mechanical pulp, waste paper, khermomechanical pulp (TMP) and chemothermo-20mechanical pulp (CTMP). The basis weight of the papers may be from 30 to 200, preferably from 35 to 150, g/m2, while ~hat of cardboard may be up to 600 g~m2. The papers produced using the copolymer~, to be used according to the inventlon, as a mixture with natural potato starch 25have markedly improved strength compared with papers obtainable in the presence of the same amount of natural potato ~arch.
In the Examples which follow, parts and per-centage are by weight. The viscosities were determined 30in agueous solution at a ~olids concentration of 3.5% by weight and at 20C in a Brookfield vi~cometer at 20 rpm.
Sheet formation was carriad out on a Rapid-K~then laboratory sheet former. The dry breaking length wa~
determined according to DIN 53,112, Sheet 1, the Mullen 35dry bursting pre~ure according to DIN 53,141, the CMT
value according to DIN 53,143 and the Brecht-Inset tear propagation strength according to DIN 53,115. Testing of 2~5~0 O.Z. 0050/40659 the sheets was carried out after conditioning for 24 hours at 23C and a relative humidity of 50%.
The R value of the copolymars was determined according to H. Fikentscher, Cellulosechemie 13 (1932), 58-64 and 71-74, at 25C in 5~ strength aqueous sodium chloride solution and at a polymer concentration of 0.1%
by weight; K = k 103.
The following starting materials were used:
Copolymer 1 Copolymer o~ 90 mol % of N-vinylformamide (VFA) and 10 mol % of 3-methacrylamidopropyltrLmethylammonium chloride (MAPTAC~
Copolymer 1 was prepared by initially taking 800 g of cyclohexane and 3 g of protective colloid described in Example 1 of EP-A 0 290 753 in a 2 1 flask provided with a stirrer, a thermometer, a gas inlet tube and a reflux conden6er. The initially taken mixture was heated to 50C under a ni~rogen atmosphere and while tirring at a stirrer speed of 300 revolutions per minute. A~ soon as this temperature had been reached, a solution of 117 g of N-vinylformamide, 80 g o~ a 50%
~tre~gth by weight aqueous ~olution of 3-methacrylamido-propyltrimathylammonium chloride~ 0.15 g of ~odium diethylenetriaminepentaacetate, 0.65 g of 2,2'-a2Obis-(2-amidinopropane) dihydrochloride and 100 g of water was added in the cour~e of 30 minute~. The p~ of ~he aqueous pha~e wa~ 6.5. The reaction mixture was then stirred for 16 hours at 50C. Thereafter, the temperature was increased to 78C and 134 g of water were distilled off azeotropically with the aid of a water ~eparator. The resulting white bead-like solid was filtered off, washed with 200 g of cyclohexane and freed from the reqidual solvent under reduced pra~sure. 163 g of a copolymer having a solidæ content o~ 96.4% by weight were obtained.
The R value was 180.
Copolymers 2 to 5, who~e compositions are ~hown in Table 1, wers prepared similarly to the abovementioned ~ ~ 3 ~
.
.
; - 12 - O. Z . 0050/40659 preparation method. ,:
'" '' '.
~ '~. ''. ' -~: ~
: ~ .
' .
~ : , '' , :: .. . .
,:, :.
: . .
. ,:, :: . -, , .
~"''.,. ::
'' ' ""
'`' `'''" ' ,~." `' ' 2 ~
- 13 - O.Z. 0050/40659 Copolymer Mol % Mol % Solids K value yFAl~ MAPTAC2) content (%) 2 8~ 20 96.~ 180 3 70 30 91.0 203 4 60 ~0 94.1 189 ~8.0 200 VFA = N-vinylformamide o 2~ MAPTAC = 3-methacrylamidopropyltrimethylammonium chloride The following polymers were used for comparison:
Copolymer 6: Homopolymer of N-vinylfonmamide having a solids con~ent of 96.6% and a R value of 203, prepared sLmilarly to the method for cupolymer 1 by homopol~merization of N
vinylformamide.
Copolymer 7: Partially hydrolyzed polymer 6, which wa8 obtained by homopolymerization of N-vinylformamide by the preparation method stated for copolymer 1, 105 g of a 38%
~trength hydrochlo:ric acid being added before removal of the water and the mixture being stirred for 3 hours at 50C
before the wa~er was di~tilled off azPo-tropically. The degree of hydrolysi~ was 42%, the ~ value was 185 and the solids content wa~ 93.5%.
Copolymer 8: Thi~ i~ likewi~e a hydrolyzed homspolymer of N-vinylformamide which was prepared sLmilarly to copolymer 7, except that 211 g of 38% ~trength hydrochloric acid were used in the hydrolysis. The degree of hydrolysis was about 90~, the K value wa~ 195 and the 301ids content wa~ gO.6%.
A degree of hydrolysi~ of 90% maans tha~
90% of the formamide -group~ origlnally ,, ~, , ,. ,. . , : . . , ~ -, ,,.: .: , " ,, ,, , ,,:, , : "
203~
.
14 - O.i~. 0050/40659 present in the polymer have been converted into amino groups or the coxresponding ammonium salt groups.
EXANPLES
Wood-containing and kaolin-containing newspaper stock having a consistency of 2 gtl, a pH of 6 and an alum content of 0.5% by weight was first pxepared. This paper stock was used as a model substance for all Ex-amples and Comparative Examples. With the aid of a Schopper-Riegler apparatuC, the freeness (SR), the drainage ~ime ( i2 . the tLme in which 600 ml of white water flow out of the apparatus) and the optical trans-mittance of ~he white wa~er in % were first detenmined for ~he paper ~tock model d~scribed abov~. 1 1 samples of the paper stock described above ~ogether with the amounts of copolymers 1 to 8 stated in Table 2 were then tQsted. The results obtained are showm in Table 2.
i , ~
'~'. '' '~ ' , i ,~' ' ' " "', ' ',~
" ' ' ',: . . '' .
~ !. . ~ .; " . .,, ' , . !" I
20~3~3 -15 - O. Z . 0050/40659 ''~
,~ .
f~ c~
a~ o u~
~ o E~ o ~,, ~ ~ ~ u~
o r` _I ~ o ~ ~ c~
a) o ~ u~
.~ ~ ,:
~J a~ N el' '~
O W
O I~
o u~ ~n ~ er q~ co In GO ' t~ O ~ O ~:1 ~ O O
~1 0 ,1 .
0 3 Cl) ~O ~O 11~ In Ll~ ao 1~ QO .
- . , .,. ~
~3 er d , N 00 ~ u~
1:~ ~ ~ ~ ~ ~ Ir~
_ ~ , ... ....
~q . ~D ~ O~ CO _~ tD r~ ~ -c~ ~ ""
c~ o) t~ ~r 5P ~P ~ t~a er O u~
I
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P
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,~
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2 0 3 0 ~ 4 O
16 - O.Z. 0050/40659 To test the paper strength, the strength agen~s : :
1 to S which are stated below and w~re prepared by heating natural potato starch with the copolymers stated in Table 3 were tested.
S TAB~E 3 .
Strength Obtained by reaction with Vii~cosity of the agentaqueous solution of :
the strength agent :
_ [mPa.s]
1 Copolymer 1 314 :-2 Copol~mer 3 850 3 Copolymer 5 858 .
4Copolymer 6 tcomparison) 180 5Copolymer 7 ~comparison) 668 15Streng~h agenti~ 1 to 5 described above were each -te~ked in the abovementioned paper stock. The amount ~.
added was 3.0~ by weight, ba~ed on dry paper stock, in ~ ::
all cases. The test result~ are shown in Table 4.
20 Example Strength CMT Dry Dry COD o~
agent No. value bur~ting breaking w~ite added ~o pre~sur~e length water paper .
stock [N] [kPa] [m] [m~ O2/l]
_ ....... __ .: . , .
6 1 169 169 3266 128 ~
7 2 185 173 3457 167 .
8 3 184 184 3322 112 `.
Comparative : ~
Example : :.
- 126 136 2667 162 ~.... ..
6 Natural 145 148 2836 276 ~:
potato starch 7 4 148 149 2971 327 ::
8 5 200 194 3349 146 .::
Further strength agent~ were prepared by heating ''.
JP-A-118 406/86 discloses water-soluble poly-vinylamines which are prepared by polymerizing N-vinyl-formamide or mixtures of N-vinylformamide with other water-soluble monomers, such as acrylamide, N,N-dialkyl-acrylamide~ or diallyldialkylammonium ~alts and subse-quently hydrolyzing the polymers with bases, eg. ethyl-i~mine, diethylamine, ethylenediamine or morpholine. ~he polyvinylamine~ are used as drainage aids and rekention aids in papermaking and as flocculant~ for wastewaters.
U.S. Patent 4,421,602 di~closes polymers which are obtainable by partial hydrolysis of polyl-N-vinyl-formamide with acids or bases. As a result of the hydrolysi~, these polymers contain ~inylamine and N-vinylformamide units. They are u~ed, for example inpapermaking, as drainage aids, flocculants and retention aids.
EP-A-0 220 603 discloses, inter alia, that N-vinylformamide can be subjectecl to copolymerization together with basic acrylates, such as dimethylaminoethyl acrylate, or N-vinylimidazoline~, in ~upercritical carbon dioxide. The resulting finely divided copolymers are -~sed in the partially hydrolyzed form, in which ~hey contain vinylamine unit~, for example a~ retention aids and flocculants in papermaXing.
EP-A-0 282 761 disclose~ a proce~s for the production of paper, ~oard and cardboard having high dry ctrength, in which the dry ~trength agent used is a mixture of cationic polymers, which may also contain, ~mong typical monomer~, pol~merized unit~ of vinylamine, and natural potato ~tarch, the potato starch baing converted into a water-soluble form by heating in an ;';"
`
2~3~
- ; - 2 - O.Z. 0050/40659 aqueous medium in the presence of a cationic polymer to tPmperatures above the gela~inization temperature of natural potato starch in the absence o~ oxidizing agents, polymerization initiator~ and alkali.
It is an ob~ec~ of the present invention to provide papermaking assistants which ideally are more effective than the conventional ones and which are technically more readily available.
We have found that this objec~ is achieYed, according to the invention, by a process for the produc-tion of paper, board and cardboard by draining a paper stocX in the presence of ~ polymex containing N-vinyl-formamide units, if a nonhydrolyzed copolymer which contains, as polymerized units, (a) from 99 to 1 mol % of N-vinylformamide and (b) from 1 to 99 mol % of one or more water-soluble basic monomer~ of the formula CH 2=C ~ ~A~ R 3 ye ( I ) or O R~' CH 2=CH--CH 2~i,CH ~C~=CH 2 ye R ~ R6 (II) where Rl is H, CHs or C2H5, R2, R3 and R4 are each H, CH3, C2Hs or (-CH2-CH2-O-)nH, Rs and R6 are each Cl-C1O-alkyl, A
is Cl-C~-alkylene~ n i~ from 1 to 6 and ye is an anion, i~
used in an amount of from 0.01 to 3.5~ by weight, based on dry paper stock, as the polymer containing N-~inyl-formamide units.
~ he ~dvantage of the nonhydroly2ed copolymerscontaining N-vinylformamide uni~ over the previously u~ed hydrolyzed copol~mers which contain vinylamine units a~ter the hydrolysis i8 that the hydrolysis, which is di~ficult to carry out in many cases, is dispensed with and effective papermaking assistants are obtainable by direct copolymerization.
. A ~uitable mo~omer (a) of the copolymers is : ' 2~ 0 ~` - 3 - O.Z. 0050/40659 N-vinylformamide. This monomer is present in the copoly-mers in an amount of from 1 to 99, preferably from 60 to 95, mol %.
Suitable monomers of group (b) are the compounds of the formula I, of which the following compounds may be stated by way of examples N-tximethyl-N-tacrylamidoethyl)-ammonium chloride, N-trimethyl-N-(methacrylamidoethyl)-a~monium chloride, N-trimethyl-N-(acrylamidoethyl3-ammonium methosul~ate, N trimethyl-N-(methacxylamidoethyl)-ammonium metho-sulfate, N-ethyldimethyl-N-(methacrylamidomethyl)-ammonium etho-~ul~ate, N-ethyldimethyl N (acrylamidomethyl)-ammonium etho-sulfate, N-trimethyl-N-(acrylamidopropyl)-ammonium chloride, N-trimethyl-N-(methac~ylamidopropyl)-ammonium chloride, ~;
N-trimethyl-N-(acrylamidopropyl)-ammonium methosulfate, ~ ~`
N-trimethyl-N-(methacrylamidopropyl)-ammonium metho-sulate, N-ethyldimethyl-N-(methacrylamidopropyl)-ammonium etho-sulfate and N-ethyldimethyl-N-(acrylamidopropyl)-ammonium eth~sulfate.
N-Trimethyl-N-(methacryl~midopropyl)-ammonium ~ ~ -chloride is pxeferred.
Other suitable monomers of group (b) are the compounds o~ th~ formula II. Example~ o~ compounds of this type are diallyldimethylammonium chloride, diallyl-dimethylammonium bromide, diallyldiethylammoniumchloride and diallyldiethylammonium bromide. Diallyldimethyl-ammonium chloride i8 preferably used. The anion ye is an acid radical and is preferably chloride, bromide, iodide, sulfate, metho~ulfate or ethosulfate.
Among the monomers of group (b), the compounds of the formula I or II may be present in the copolymers ~;
either alone or as a mixture with one another. It is , 2~3~0 - 4 - O.Z. 0050/40659 al~o possible to use a plurality of compounds of the formula I or II in the copolymerization of the monomer (a). The monomers of group (b) are pre6ent in the copolymers in an amount of from 99 to l, preferably from 4 0 to 5, mol %.
The copol~meriæa~ion of the monomers (a) and (b) is carried out in aqueou~ ~olution in the pre~ence of polymerization initiators which decompose into free radical~ under the polymerization conditions. ~xamples of suitable polymerization initiators are hydrogen peroxide, alkali metal and ammonium salt~ of peroxy-disulfuric acid, pero~ides, hydroperoxides~ redox cata-lyst~ and in particular nonoxidizing initiators, such as azo compounds which decompose into free radicals. Water-æoluble azo compound~, such as 2,2'-azobi~-(2-amidino-propane) dihydrochloride, 2,2~-azobis-(N,N'-dimethylene-isobutyramidine~ dihydrochloride or 2,2' azobi~-[2~
methyl-N-(2-hydroxyethyl~-propionamide], are preferably u~ed. The polymerization initiators are employed in conventional amount~, for example in amount~ of from 0.01 to 5% by weight, based on the monomers to be polymerized.
Polymerization can be carried out in a wide temperature range9 under atmospheric pres~ure, reduced or super-atmospheric pres3ure, in appropriately de~igned apparatuse~. The polymerization is preferably effected under atmospheric pres~ure and at not more than 100C, in par~icular from 30 to 80C. The concentration of the mono~ers in the agueou~ solution i~ preferably cho3en to give polymex ~olutions who~e solids content i8 from 10 to 90, prefer~bly from 20 to 70, % ~y weight. ~he pH of the reaction mixture i8 brought to 4-10, preferably 5-8.
Depending on the polymexization condition~
copolymers having different moleclllar weights are ob-tained~ To characterize a copolymer, the R value accord-ing to H. Fikent~cher i~ ~tated instead of tha molecular weight. The ~ values (measured in 5% strength aqueous ~odium chloride solution at 2SC and at a polymer ' , ', :
2 ~
- - 5 - O.Z. 0050/40659 concèntration of 0.1% by weight) are from 5 to 350.
Copolymers having low molecular weights and corres-pondingly low X values axe obtained by the conventional methods, ie. the use of relatively large amounts of 5peroxide in the copolymerization or ~he use of poly-merization regulators or combinations of the two measures stated. Polymers having a high K value and high mole-cular weights are obtained, for example, by polymerizing the monomers by reverse ~uspension polymerization or by 10polymPrizing monomers (a) and (b) by the water-in~oil polymerization process. In the reverse suspen~ion polymerization proce3s and in water-in-oil polymeriza-tion~ saturated hydrocarbons, for example hexane, heptane, cyclohexane or decalin, or aromatic hydro-15carbons, such as benzene, toluene, ~ylene or c~mene, are used a,s the oil phase. The ratio of oil phase to aqueous pha~e in reverse suspension polymerization is, for example, from 10 : 1 to 1 : 10, preferably from 7 : 1 to 1: 1.
20In order to disperse the aqueous monomer solution in an inert hydrophobic liquid, a protecti~e colloid is required, the purpo~e of which is to stabilLze the suspension of the aqueous monomer 301ution in the inert hydrophobic liquid. The protective colloids furthermore 25affect the particle size of the polymer beads formed by polymeri~ation.
Examples of suitable protective colloids are the ~ub~tances described in U.S. Patent 2,982,749. The protective colloids which are disclosed in German Patent 302,634,486 and are ob~ainablet for example, by reacting oils and/or resins, each of which have allyl hydrogen atoms, with maleic anhydride are also suitable. Other ~uitable protective colloids are disclosed in, for example, German Patent 2,710,372 and are obtainable by 35thermal or ~ree radical solution or mass polymerization from 60-99.9% by weight of dicyclopentadiene, 0-30% by weight of styrene and 0.1-10% by weight of maleic ' '; ',, , , ' "~'~ "' 2~3~4~
~ - 6 - r~.z. 0050/40659 .
anhydride.
Other suitable protective colloids are graft pol~mers which are obtainable by grafting polymers (a) of a3 from ~0 to 100% by weight of monovinylaromatic monomers, b) from 0 to 60% by weight of monoethylenically un~
saturated carboxylic acids of 3 to 6 carbon atoms, maleic anhydride ~,nd/or itaconic anhydride and c) from 0 to 20% by weight of other monoethylenically : :
unsaturated monomers, ::
with the proviso that the sum of the percentages by : ~:
weight (a) to (c) i~ always 100 and the polymers (A) have ~ -:
a number average molecular weight of from 500 to 20,000 : -~
and a hydrogenation iodine number (according to DIN
53,241) of fxom 1.3 to Sl, with monomer mixtures of ;~
1) from 70 to 100% by weight of acrylates and/or ::.
methacrylates of monohydric alcohols of 1 to 20 .;~
carbon atoms, 2) from 0 to 15~ by weight of monoethylenically un~
sa~ura~ed carboxylic acids of 3 to 6 carbon atoms, : ~ .
maleic anhydride and~or itaconic anhydride, ~ ~:
: 3) from 0 to 10% by weight o~ acrylic monoesters and/or methacrylic monoesters of at least dihydric alcohols, -:: .
4) from 0 to 15% by weight of monovinylaromatic mono-mers and S) from 0 to 7.5% by weight of acrylamide and/or methacrylamide, with the proviso that the sum of the percentages by w~ight a) to e) i8 always 100, :
at not more than 150C in an ~nert hydrophobic diluent in the presence of polymerization initiators, the monomers being u~ed in an amount of from 97.5 to 50% by weight, ;:~
based on the mixture of polymer ~A) and monomers.
Protective colloids of this typs are described in :~
EP-A-0290 753.
When an aliphatic hydrocarbon is used as the inert hydrophobic liquid in the reverse suspension 2 03 ~ ~ 4 ~
- 7 - O.Z. 0050/40659 polymerization, a mixture of an inorganic suspending agent based on modified finely divided minerals and a nonionic surfactant has proven very advantageous as the protective colloid.
The inorganic suspending agents, which have a low hydrophilic/lyophilic balance, are the agents usually employed in reverse suspension polymerization processes.
The mineral component of thPse substances is, for ex-ample, bentonite, montmorillonite or kaolin. Finely divided minerals are modified by being treated with salts of long-chain amines, for example C8-C24-amines, or quaternary ammonium salts, th~ amine salts or the quater-nary ammonium salts being intercalated between the individual layers of the finely divided minerals. The quaternized ammonium ~alt~ which may be used for modific-ation preferably contain 1 or 2 C10-C22-alkyl radicals.
The other ubstituents of the ammonium sal~s are Cl-C4-alkyl or hydrogen. The content of free ammonium salts of the amine modified mineral~ is no~ more than 2% by weight. Finely divided minerals modified with ammonium salts are commercially available.
~ha inorganic suspending a~ents for reverse suspension polymerization include silica which has been reacted with organosilicon compounds. Æ suitable organo-silicon compound i~, for example, trimethylsilyl chloride.
The purpoqie of the modification of the inorganic ~inely divided minerals is to improve the wettability of the minerals with the aliphatic hydrocarbon used as the outer phase of the re~erse suspension polymerization. In the case of the na~ural mineral~ having a layer-like structure, for example bentonite and montmorillonite, the re3ult of modification with amines i~ that the modified minerals swell in the aliphatic hydrocarbon and thus disintegrate into very ~ine particles. The particle size is about 1 ~m, in general from O.S to 5 ~m. The silicas reacted with organosilicon compounds have a particle size .. , . . , , ~ ., ~ .,.
' . " ;'.' '' ' ''' ' ' ' ; ''" '; ' ' ' ,"' ,- ' ' ,, ' 2~3~0 -- 8 - O.Z. 0050/40659 o~ about 10-40 nm. The modified finely divided minerals are wetted both by the aqueous monomer solution and the - -solvent and thus accumulate in the phase interface be~ween the aqueous phase and the organic phase. They -;
prevent coagulation on collision of two aqueous monomer ~ -droplets in the suspension.
After the end of the copolymerization, some of ~-the water is distilled azeotropically so that copolymers having a solids content of from 70 to 99, preferably from 80 to 95, % by weight are obtained. The copolymers are in the form of fine bead~ having a diameter of from 0.05 to 1 mm.
In contrast to the prior art, the copolymers deZ3cribed above are used in nonhydrolyzed form as an additi~e to the paper stock in the production Qf paper, board and cardboard. These copolymerZ3 contain no ~inyl-amine uni~s. They increase ~he rate of drainage of the paper stock, 80 that the production speed in papermaking can be incxeased. The copolymers ~lso act as retention aids for fib~rs and fillerZ3 and simultaneously as floc-culants. To achieve the stated effects, the copolymers are added to the paper stock in ~nountZs of from 0.01 to about 0.8% by weight, based on dry paper stock. Using larger ~mounts of copolymers impartZ3 dry ætrength. In order to achieve such effectZ3, the polymerZ~ are used in amounts of about 0.5-3.5ZZ~ by weight, hased on dry paper 3tock. The uZ~e of the stated copolymers to~ether with natural potato starch as dry strength agents is par-ticularly preferred. Such mixtures have good retention for paper fibers in tha paper stock. The COD of the white water i8 con iderably reduced by mean~ of these mixtures compared with natural starch. ~he troublesom substanceZ3 present in the wator circulationZ3 of paper machines hava only a slight adverZ3e ~ffect on the e~fici-ency of the mixtures of the copolymers to be used accord-ing to the invention and natural Z~tarch. The pH of the paper stock suspension may he ~rom 4 to 9, preferably ,~, '. ,, ,'.:
~03~5~
- - 9 - O.Z. 0050/40659 from 6 to 8.5. These mixtures of natural starch and cationic polymer which are added to the paper stock for imparting dry strength are preferably prepared by heating natural pota~o starch in the presence of the non-hydrolyzed copolymers in aqueous solution to temperaturesabove the gelatinization temperature of the natural potato starch, in the absence of oxidizing agents, polymerization initiators and alkali. The natural potato s~arch is modified in this manner.
The gelatinization temperature of the starch is the temperature at which the birefringence of the starch particles is lost (cf. Ullmanns ~nzyklopadie der technis-chen Chemie, Urban und Schwarzenberg, Munich-Berlin, 1965, 16th volume~ page 322).
Modification of the natural potato starch can be carried out in various ways. A digested natural potato starch which i8 in the form of an aqueous ~olution can be reacted with the suitabla cationic polymers at from 15 ~o 70C. At even lower temperatures~ longer contact times are required. If the r~action is carried out at even higher temperatures, for example up to 110C, shorter contact times, eg. from 0.1 to 15 minutes, are required.
The simplest method of modifying natural potato starch is to heat an aqueous suspension of the starch in the presence of the suitable cationic copolymer~ to above the gelati~ization temperature of ~he natural potato starch.
Por modiication, the ~tarch i~ generally heated to 70-llO~C, the reaction being carried out in pressure~resist~
ant apparatu~es at above 110C. However, it is also pos3ible fir~t to heat an aqueous suspension o~ natural potato ~tarch to 70~110C and to bring the starch into ~olution and then to add the cationic copolymer required for modification. Solubilizing of the starch is carried out in the absence o~ oxidizing agents, initiators and alkali, in the course of about 3 minute~ to 5 hour~, pre~erably from 5 to 30 minute~. Higher temperature~
require a ~horter residence time here.
' :
~ 0 3 0 3 4 ~ :
- - 10 - O.Z. 0050/40659 From 1 to 20, preferably from 8 to 12, parts by weight of a single sui~able nonhydrolyzed cationic copolymer or of a mixture o such copolymer~ are used per 100 parts by weight of natural potato starch. As a result of the reaction with the cationic copolymers, the natural potato starch is con~erted into a water-soluble form. The vi~cosity of the aqueou~ phase of the reaction mixture increases. A 3.5% strength by weight aqueous solution of the dry strength agent has viscosities of 10from 50 to 10,000 mPa.s (measured according to Brookfield at 20 rpm and 20C).
The copolymers to be used according to the invention can be employed in the production of all known paper, cardboard and board grades, for example for the 15production of writing, printing and packaging papers.
The papers may be produced from a large number of dif-ferent fiber materials, for example from bleached or unbleached sul~ite or ~iulfate pulp, mechanical pulp, waste paper, khermomechanical pulp (TMP) and chemothermo-20mechanical pulp (CTMP). The basis weight of the papers may be from 30 to 200, preferably from 35 to 150, g/m2, while ~hat of cardboard may be up to 600 g~m2. The papers produced using the copolymer~, to be used according to the inventlon, as a mixture with natural potato starch 25have markedly improved strength compared with papers obtainable in the presence of the same amount of natural potato ~arch.
In the Examples which follow, parts and per-centage are by weight. The viscosities were determined 30in agueous solution at a ~olids concentration of 3.5% by weight and at 20C in a Brookfield vi~cometer at 20 rpm.
Sheet formation was carriad out on a Rapid-K~then laboratory sheet former. The dry breaking length wa~
determined according to DIN 53,112, Sheet 1, the Mullen 35dry bursting pre~ure according to DIN 53,141, the CMT
value according to DIN 53,143 and the Brecht-Inset tear propagation strength according to DIN 53,115. Testing of 2~5~0 O.Z. 0050/40659 the sheets was carried out after conditioning for 24 hours at 23C and a relative humidity of 50%.
The R value of the copolymars was determined according to H. Fikentscher, Cellulosechemie 13 (1932), 58-64 and 71-74, at 25C in 5~ strength aqueous sodium chloride solution and at a polymer concentration of 0.1%
by weight; K = k 103.
The following starting materials were used:
Copolymer 1 Copolymer o~ 90 mol % of N-vinylformamide (VFA) and 10 mol % of 3-methacrylamidopropyltrLmethylammonium chloride (MAPTAC~
Copolymer 1 was prepared by initially taking 800 g of cyclohexane and 3 g of protective colloid described in Example 1 of EP-A 0 290 753 in a 2 1 flask provided with a stirrer, a thermometer, a gas inlet tube and a reflux conden6er. The initially taken mixture was heated to 50C under a ni~rogen atmosphere and while tirring at a stirrer speed of 300 revolutions per minute. A~ soon as this temperature had been reached, a solution of 117 g of N-vinylformamide, 80 g o~ a 50%
~tre~gth by weight aqueous ~olution of 3-methacrylamido-propyltrimathylammonium chloride~ 0.15 g of ~odium diethylenetriaminepentaacetate, 0.65 g of 2,2'-a2Obis-(2-amidinopropane) dihydrochloride and 100 g of water was added in the cour~e of 30 minute~. The p~ of ~he aqueous pha~e wa~ 6.5. The reaction mixture was then stirred for 16 hours at 50C. Thereafter, the temperature was increased to 78C and 134 g of water were distilled off azeotropically with the aid of a water ~eparator. The resulting white bead-like solid was filtered off, washed with 200 g of cyclohexane and freed from the reqidual solvent under reduced pra~sure. 163 g of a copolymer having a solidæ content o~ 96.4% by weight were obtained.
The R value was 180.
Copolymers 2 to 5, who~e compositions are ~hown in Table 1, wers prepared similarly to the abovementioned ~ ~ 3 ~
.
.
; - 12 - O. Z . 0050/40659 preparation method. ,:
'" '' '.
~ '~. ''. ' -~: ~
: ~ .
' .
~ : , '' , :: .. . .
,:, :.
: . .
. ,:, :: . -, , .
~"''.,. ::
'' ' ""
'`' `'''" ' ,~." `' ' 2 ~
- 13 - O.Z. 0050/40659 Copolymer Mol % Mol % Solids K value yFAl~ MAPTAC2) content (%) 2 8~ 20 96.~ 180 3 70 30 91.0 203 4 60 ~0 94.1 189 ~8.0 200 VFA = N-vinylformamide o 2~ MAPTAC = 3-methacrylamidopropyltrimethylammonium chloride The following polymers were used for comparison:
Copolymer 6: Homopolymer of N-vinylfonmamide having a solids con~ent of 96.6% and a R value of 203, prepared sLmilarly to the method for cupolymer 1 by homopol~merization of N
vinylformamide.
Copolymer 7: Partially hydrolyzed polymer 6, which wa8 obtained by homopolymerization of N-vinylformamide by the preparation method stated for copolymer 1, 105 g of a 38%
~trength hydrochlo:ric acid being added before removal of the water and the mixture being stirred for 3 hours at 50C
before the wa~er was di~tilled off azPo-tropically. The degree of hydrolysi~ was 42%, the ~ value was 185 and the solids content wa~ 93.5%.
Copolymer 8: Thi~ i~ likewi~e a hydrolyzed homspolymer of N-vinylformamide which was prepared sLmilarly to copolymer 7, except that 211 g of 38% ~trength hydrochloric acid were used in the hydrolysis. The degree of hydrolysis was about 90~, the K value wa~ 195 and the 301ids content wa~ gO.6%.
A degree of hydrolysi~ of 90% maans tha~
90% of the formamide -group~ origlnally ,, ~, , ,. ,. . , : . . , ~ -, ,,.: .: , " ,, ,, , ,,:, , : "
203~
.
14 - O.i~. 0050/40659 present in the polymer have been converted into amino groups or the coxresponding ammonium salt groups.
EXANPLES
Wood-containing and kaolin-containing newspaper stock having a consistency of 2 gtl, a pH of 6 and an alum content of 0.5% by weight was first pxepared. This paper stock was used as a model substance for all Ex-amples and Comparative Examples. With the aid of a Schopper-Riegler apparatuC, the freeness (SR), the drainage ~ime ( i2 . the tLme in which 600 ml of white water flow out of the apparatus) and the optical trans-mittance of ~he white wa~er in % were first detenmined for ~he paper ~tock model d~scribed abov~. 1 1 samples of the paper stock described above ~ogether with the amounts of copolymers 1 to 8 stated in Table 2 were then tQsted. The results obtained are showm in Table 2.
i , ~
'~'. '' '~ ' , i ,~' ' ' " "', ' ',~
" ' ' ',: . . '' .
~ !. . ~ .; " . .,, ' , . !" I
20~3~3 -15 - O. Z . 0050/40659 ''~
,~ .
f~ c~
a~ o u~
~ o E~ o ~,, ~ ~ ~ u~
o r` _I ~ o ~ ~ c~
a) o ~ u~
.~ ~ ,:
~J a~ N el' '~
O W
O I~
o u~ ~n ~ er q~ co In GO ' t~ O ~ O ~:1 ~ O O
~1 0 ,1 .
0 3 Cl) ~O ~O 11~ In Ll~ ao 1~ QO .
- . , .,. ~
~3 er d , N 00 ~ u~
1:~ ~ ~ ~ ~ ~ Ir~
_ ~ , ... ....
~q . ~D ~ O~ CO _~ tD r~ ~ -c~ ~ ""
c~ o) t~ ~r 5P ~P ~ t~a er O u~
I
_I
~ ~ U~
V
P
. ~ ~
,~
~1 ~ ~ ~ ~ u~ .
2 0 3 0 ~ 4 O
16 - O.Z. 0050/40659 To test the paper strength, the strength agen~s : :
1 to S which are stated below and w~re prepared by heating natural potato starch with the copolymers stated in Table 3 were tested.
S TAB~E 3 .
Strength Obtained by reaction with Vii~cosity of the agentaqueous solution of :
the strength agent :
_ [mPa.s]
1 Copolymer 1 314 :-2 Copol~mer 3 850 3 Copolymer 5 858 .
4Copolymer 6 tcomparison) 180 5Copolymer 7 ~comparison) 668 15Streng~h agenti~ 1 to 5 described above were each -te~ked in the abovementioned paper stock. The amount ~.
added was 3.0~ by weight, ba~ed on dry paper stock, in ~ ::
all cases. The test result~ are shown in Table 4.
20 Example Strength CMT Dry Dry COD o~
agent No. value bur~ting breaking w~ite added ~o pre~sur~e length water paper .
stock [N] [kPa] [m] [m~ O2/l]
_ ....... __ .: . , .
6 1 169 169 3266 128 ~
7 2 185 173 3457 167 .
8 3 184 184 3322 112 `.
Comparative : ~
Example : :.
- 126 136 2667 162 ~.... ..
6 Natural 145 148 2836 276 ~:
potato starch 7 4 148 149 2971 327 ::
8 5 200 194 3349 146 .::
Further strength agent~ were prepared by heating ''.
5 ~
" - 17 - O. Z . 0050/40659 natùral potato starch in ~queous suspension for 15 minutes at ~0-110C in the pre~ence of the copolymers stated in Table 5.
Strength Obtained by reaction with Vi~cosity of the ~:
agent copolymer of aqueous ~olution ..~ mol% ...mol % of of K of the strength of VFA and D~DMACl) value agent ~ rl[lPa. Sl_ 6 30 70 93 169 ~ ~.
" - 17 - O. Z . 0050/40659 natùral potato starch in ~queous suspension for 15 minutes at ~0-110C in the pre~ence of the copolymers stated in Table 5.
Strength Obtained by reaction with Vi~cosity of the ~:
agent copolymer of aqueous ~olution ..~ mol% ...mol % of of K of the strength of VFA and D~DMACl) value agent ~ rl[lPa. Sl_ 6 30 70 93 169 ~ ~.
7 50 50 31 180 ~
8 7~ 30 9~ 140 . :
: 1) D~DMAC = DiallyldLmethylammonium chloride :
To test strength agent~ 6 to 8 with regard to their ef f iciency, they were added to the paper tock de~cribed in Example 1 in an amounl; of 3 . 0% by weight, based on dry paper stock. The results obtained are 3hown in Table 6. ;
TABLE 6 :: -Example Strength CN~ Dxy Dry CûD of -agent No. value bur~ting breaking white :
added to pres~ure length water paper ~tock [N] [kPa] tm] ~mg 02/1]
: 1) D~DMAC = DiallyldLmethylammonium chloride :
To test strength agent~ 6 to 8 with regard to their ef f iciency, they were added to the paper tock de~cribed in Example 1 in an amounl; of 3 . 0% by weight, based on dry paper stock. The results obtained are 3hown in Table 6. ;
TABLE 6 :: -Example Strength CN~ Dxy Dry CûD of -agent No. value bur~ting breaking white :
added to pres~ure length water paper ~tock [N] [kPa] tm] ~mg 02/1]
9 ~ 1û2 191 3336 206 11 ~ 171 178 3331 ~60 In order to test copolymers 1, 3 and 5 and copolymer 6 (compari~on) with regard to their efficiency .
as dry strength agent~ 2vQn in the absence of added starch, they were added to the paper stock described in E~ample 1 in an amount of 0 . 5% by weight, based on dry paper s~ock. The results obtained are ~hown in Table 7.
, , : . , ., .. ; . .. . . . . .
2 0 3 0 ~ ~ J
18 - O. Z . 0050/40659 Ex. Comp. Copolymer CNT Dry Dry COD of --Ex. No. value burst- break- white :
added to ing ing water paper pressure length stock [N] [kPa] rm~[mg 02/l]
12 l . 143 151 2932 162 ~ .
13 3 134 145 2794 120 ~ .
14 4 132 lk3 2857 61 ;;:
:, ": ":
, ,'-. ;- '' ' ' ', ' ~ :', ~',''''' ',''"' ~: '' ' ' ' ".': :' ' ', ''. :' :
~' ,~" ' :' S ;~ V , ~ ~
as dry strength agent~ 2vQn in the absence of added starch, they were added to the paper stock described in E~ample 1 in an amount of 0 . 5% by weight, based on dry paper s~ock. The results obtained are ~hown in Table 7.
, , : . , ., .. ; . .. . . . . .
2 0 3 0 ~ ~ J
18 - O. Z . 0050/40659 Ex. Comp. Copolymer CNT Dry Dry COD of --Ex. No. value burst- break- white :
added to ing ing water paper pressure length stock [N] [kPa] rm~[mg 02/l]
12 l . 143 151 2932 162 ~ .
13 3 134 145 2794 120 ~ .
14 4 132 lk3 2857 61 ;;:
:, ": ":
, ,'-. ;- '' ' ' ', ' ~ :', ~',''''' ',''"' ~: '' ' ' ' ".': :' ' ', ''. :' :
~' ,~" ' :' S ;~ V , ~ ~
Claims (2)
1. A process for the production of paper, board and cardboard by draining a paper stock in the presence of a polymer containing N-vinylformamide units, wherein a nonhydrolyzed copolymer which contains, as polymerized units, (a) from 99 to 1 mol % of N-vinylformamide and (b) from 1 to 99 mol % of one or more water-soluble basic monomers of the formula (I) or (II) where R1 is H, CH3 or C2H5, R2, R3 and R4 are each H, CH3, C2H5 or (-CH2-CH2-O-)nH, R5 and R6 are each C1-C10-alkyl, A
is C1-C6-alkylene, n is from 1 to 6 and Ye is an anion, is used in an amount of from 0.01 to 3.5% by weight, based on dry paper stock, as the polymer containing N-vinyl-formamide units.
is C1-C6-alkylene, n is from 1 to 6 and Ye is an anion, is used in an amount of from 0.01 to 3.5% by weight, based on dry paper stock, as the polymer containing N-vinyl-formamide units.
2. A process as claimed in claim 1, wherein an aqueous solution which is obtainable by heating natural potato starch in the presence of a nonhydrolyzed copolymer in aqueous solution to above the gelatinization temperature of the natural potato starch in the absence of oxidizing agents, polymerization initiators and alkali is added to the paper stock.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3909004.3 | 1989-03-18 | ||
| DE3909004A DE3909004A1 (en) | 1989-03-18 | 1989-03-18 | USE OF NON-HYDROLYSED N-VINYLFORMAMIDE UNITS CONTAINING COPOLYMERS IN PAPER PRODUCTION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2030540A1 true CA2030540A1 (en) | 1990-09-19 |
Family
ID=6376708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002030540A Abandoned CA2030540A1 (en) | 1989-03-18 | 1990-03-14 | Production of paper, board and cardboard in the presence of copolymers containing n-vinylformamide units |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5262008A (en) |
| EP (1) | EP0418343B1 (en) |
| JP (1) | JPH03505239A (en) |
| CA (1) | CA2030540A1 (en) |
| DE (2) | DE3909004A1 (en) |
| ES (1) | ES2043361T3 (en) |
| FI (1) | FI95943C (en) |
| PT (1) | PT93472B (en) |
| WO (1) | WO1990011404A1 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5280077A (en) * | 1992-07-14 | 1994-01-18 | Air Products And Chemicals, Inc. | Process for the synthesis of oligomeric vinylamines |
| US5516852A (en) * | 1993-11-12 | 1996-05-14 | W. R. Grace & Co.-Conn. | Method of producing water-soluble cationic copolymers |
| US5473033A (en) * | 1993-11-12 | 1995-12-05 | W. R. Grace & Co.-Conn. | Water-soluble cationic copolymers and their use as drainage retention aids in papermaking processes |
| US5700893A (en) * | 1993-11-12 | 1997-12-23 | Betzdearborn Inc. | Water-soluble cationic copolymers and their use as flocculants and drainage aids |
| US5720888A (en) * | 1993-11-12 | 1998-02-24 | Betzdearborn Inc. | Water-soluble cationic copolymers and their use as flocculants |
| AU672159B2 (en) * | 1994-06-14 | 1996-09-19 | National Starch And Chemical Investment Holding Corporation | High performance PVOH stabilised EVA adhesives |
| BR9508526A (en) * | 1994-08-05 | 1997-11-18 | Nat Starch Chem Invest | Composition for hair care gel and process for hair care |
| US5609857A (en) * | 1995-04-05 | 1997-03-11 | National Starch And Chemical Investment Holding Corporation | Methods of conditioning hair which utilize polymeric N-vinyl formamide |
| DE4438708A1 (en) * | 1994-10-29 | 1996-05-02 | Basf Ag | Process for the cationic modification of starch and use of the cationically modified starch |
| US5853542A (en) * | 1995-09-11 | 1998-12-29 | Hercules Incorporated | Method of sizing paper using a sizing agent and a polymeric enhancer and paper produced thereof |
| DE19701523A1 (en) | 1997-01-17 | 1998-07-23 | Basf Ag | Polymer modified anionic starch, process for its preparation and its use |
| DE19701524A1 (en) * | 1997-01-17 | 1998-07-23 | Basf Ag | Polymer modified starch, process for its preparation and its use |
| US6599999B1 (en) | 1997-02-04 | 2003-07-29 | National Starch And Chemical Investment Holding Corporation | Hair care compositions containing polymeric N-vinyl acetamide and methods of treating hair |
| DE19713755A1 (en) * | 1997-04-04 | 1998-10-08 | Basf Ag | Process for the production of paper, cardboard and cardboard with high dry strength |
| JP4666558B2 (en) * | 2001-05-31 | 2011-04-06 | ハイモ株式会社 | Freeness improvement method |
| US7873576B2 (en) * | 2002-09-25 | 2011-01-18 | Cummins-Allison Corp. | Financial document processing system |
| AU2003268452A1 (en) * | 2002-09-06 | 2004-03-29 | University Of Pittsburgh | N-vinylformamide derivatives, polymers formed therefrom and synthesis thereof |
| US7494566B2 (en) * | 2002-09-13 | 2009-02-24 | University Of Pittsburgh - Of The Commonwealth System Of Higher Education | Composition for increasing cellulosic product strength and method of increasing cellulosic product strength |
| US7090745B2 (en) * | 2002-09-13 | 2006-08-15 | University Of Pittsburgh | Method for increasing the strength of a cellulosic product |
| BRPI0508227A (en) * | 2004-02-27 | 2007-07-17 | Univ Pittsburgh | interconnected polymer gels and use of such polymer gels in hydrocarbon recovery |
| US7919639B2 (en) | 2009-06-23 | 2011-04-05 | Chevron Phillips Chemical Company Lp | Nano-linked heteronuclear metallocene catalyst compositions and their polymer products |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1692854A1 (en) * | 1967-11-29 | 1971-10-21 | Hoechst Ag | Process for dewatering cellulose fiber suspensions |
| DE3128478A1 (en) * | 1981-07-18 | 1983-02-03 | Basf Ag, 6700 Ludwigshafen | METHOD FOR PRODUCING LINEAR, BASIC POLYMERISATS |
| JPS61118406A (en) * | 1984-11-14 | 1986-06-05 | Mitsubishi Chem Ind Ltd | Production of water-soluble polyvinylamine |
| EP0220603B1 (en) * | 1985-10-22 | 1989-09-13 | BASF Aktiengesellschaft | Process for preparing powdery polymers |
| DE3620065A1 (en) * | 1986-06-14 | 1987-12-17 | Basf Ag | METHOD FOR PRODUCING PAPER, CARDBOARD AND CARDBOARD |
| DE3706525A1 (en) * | 1987-02-28 | 1988-09-08 | Basf Ag | METHOD FOR PRODUCING PAPER, CARDBOARD AND CARDBOARD WITH HIGH DRY RESISTANCE |
-
1989
- 1989-03-18 DE DE3909004A patent/DE3909004A1/en not_active Withdrawn
-
1990
- 1990-03-14 US US07/623,954 patent/US5262008A/en not_active Expired - Fee Related
- 1990-03-14 CA CA002030540A patent/CA2030540A1/en not_active Abandoned
- 1990-03-14 JP JP2504219A patent/JPH03505239A/en active Pending
- 1990-03-14 DE DE9090904264T patent/DE59001550D1/en not_active Expired - Lifetime
- 1990-03-14 EP EP90904264A patent/EP0418343B1/en not_active Expired - Lifetime
- 1990-03-14 WO PCT/EP1990/000406 patent/WO1990011404A1/en active IP Right Grant
- 1990-03-14 ES ES90904264T patent/ES2043361T3/en not_active Expired - Lifetime
- 1990-03-16 PT PT93472A patent/PT93472B/en not_active IP Right Cessation
- 1990-11-15 FI FI905661A patent/FI95943C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| WO1990011404A1 (en) | 1990-10-04 |
| FI95943C (en) | 1996-04-10 |
| DE59001550D1 (en) | 1993-07-01 |
| EP0418343A1 (en) | 1991-03-27 |
| US5262008A (en) | 1993-11-16 |
| EP0418343B1 (en) | 1993-05-26 |
| ES2043361T3 (en) | 1993-12-16 |
| PT93472B (en) | 1996-03-29 |
| JPH03505239A (en) | 1991-11-14 |
| PT93472A (en) | 1990-11-07 |
| DE3909004A1 (en) | 1990-09-27 |
| FI95943B (en) | 1995-12-29 |
| FI905661A0 (en) | 1990-11-15 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Dead |