CA2214367A1 - Dry strength resin compositions - Google Patents

Abstract

The tensile strength properties of paper are improved by adding to paper stock a resin composition comprising a water-soluble polymer containing a polyhydric alcohol such as sorbitol in the backbone of the polymeric molecule.

Description

~T BY:ATTORNEYS AT LAff TH~ 2~-'CA oi2~~436i 1997-09'702443 6637~ 6~ 8440;# i~l5 O

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Docke:t No~/PA
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~ExprQs~ Ma~ill~s labe~ tr r A~ 3~?7~J5.
Date of D~poeit ~~ly ;2J Jr ~
I ~r~by certi~y that~i~ ,~or~d'r~e i8 bel~g depo~ited with the United St~te~ Po~l~c~rsee llc~yLF ~t1 Mall Po8t Of~ic~ to Ad~l.~~e~ servi~r 37 CFR 1 10 on the ~ate 1n-lte~sted ~ove ~d i~ e~ tho C:. ieol~ r Of P~eent~ d Tradeq~ hi~g~on,--~20~31.

~Prlnted nyP~5o~ por~or~ mailin~ pal~e~ or fee~

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DRY ~S~N~-~n RE~IN ~ 3ITIONS

BAckgrou~d Qf the Inventinn 1. 0 FiPl ~1 of the InYention:
The pre~ent lnvention relate~ to re~in ~ompo~i'cions adapted ~o ~e applied to f ibrvu~ ~strates ~o a~ to improv~ ~heir phy~3ical propertie~, notably the d~ ren~th 5 ~ paper ~ trate~.
It i~ ~esirable to i~ J~: the dry stren~th propertie~
of paper and paper~oard. The dry ~trength prope~ie~ of paper and p~perboard are go~exned by ~heir s~cructural ele~ent~ such as fiber strength and ~iber-fiber bonding, as 10 well a~ other ~actor~ including ~iber lerlgth, ~heet formatiorl, s~ee~ f'aw~, etc. Irl order to impro~re the in~ernal dry strength prop~rties of paper and paperboard, chetnical additive~ are ~ypically ad~ed thereto. The primary purpose o~ s~h chemic~l additive8 is to atugment 15 fiber-fi~er bonding in th~ p~per Rh~et. Interfiber hydrogen b~n~s ~ a~ a natural resu~t of drying a wet S~T BY:ATTORNEYS AT L~W TH~F; ~-28-~A 02il436i l997-09-02 ~13~3~B440;# 5~15 , paper web . Although ~he de$~ree o~ interf iber h~nd; n~ ca~
~e con~roi led thxo~gh mechani~al refining such a~ beating, nonfibrou~ a~lditi~e6 'chat can er~h~ce inter~iber bor~in~
are con~tantly ~ought~
5 2.0 Diccu6cion of Related Ar~:
In an effort to impro~re the dry ~trength prope~cie~ of paper, ~theti~ re~inF~ wer~ first u~ed in the early 1940 ' and l9S0' ~, ~UCh a~ f~r e!xample, acrylamide polymers .
Polym~ of polyacrylaTnide were ~und to po~ess uni~ue O pro~er~ie~ that ma~e them e~pecially effecti~re a~ dry-~treng~h re~ins. While o~hex type~ of 8yntheti~ dry-~rength re~in~ are T ~i~Gll_e~ he liter~ture, commercial products are primarily 3~ased on ~crylamide.
There are many benef i~ to be gained ~rom the uoe o~
dry-~treng~h addi~ive~. Refining can ba re~uced while ~,in1~ ;n;n~ ~aper atrength, resulting ;n energy ~a~ing~ ~nd i~re~ied prod~lckion. ~trength propertie~ ~a~ be ~naint~ e~ while ~ tituting a lower~rength, lower-co~t ~urnish. In adclition, d~y strength can 1:~ inçrea~d witho~t a co~e~p~di ng increa~e in appare~ ~ensity, as would be the ca~e with increased ref ining .
In additio~ to ~he a~ore-~en~io~ed acrylamide polymer~r variOuB othB~ c~mponi~ions ha~ ~een report~d as providing dry-~trength p~opertie~. Mo6t of the~e composition~ c~n be clas~i~led as being ca~ionic non-acrylam~de-cont~ polymex~, for exam~le, vinyl pyridine and ~o~olymer~ thereo~, vinyl ~ulfonium polymer~, polyacrylic hydrazide, ~a~ionic acrylate copolymers, ~ T BY:ATTORNEYS AT L4U TH&F; ~-~8-~A~02il436i 1997-09--024~3 6637 ~13~32~44û.# 6~15 ~ O

polyvi~yli~idazoline, and co~d~n~ation polymer~ of.
polyamine~, ketone~ and ald~hyde~. Oth~r dry-st~ength additives include water ~olu~le, hydrop~ natural polymer~ ~uch as ~tarch, ~egetable gum~, and carb~xymethyl cellulose. TIow~var, there ~a a ~o~t.;nu~n~ need to provide dry-stre~gth paper additive~ having imp~ove~ propertieo.
3.0 Deaçri~tion o~ ~h~ ~n~ent;~n:
The present invention i~ ~ire¢ted to re8~n compo~itions which are ext~e~ely u~efu~ in ~he production ~f paper product~ and which provid~ excellen~ dry strength propertieA to paper and p~perho~rd. More particula~ly, the pre~e~t invention i~ directed ~o resin compo~ition~
comprising water-soluble polymer~ cont~;n;n~ a polyhydric alcohol ~uch a~ sorbitol in the back~one of the polymeric molecule. It has been found that ~uc~ water-~oluble poly~er~ v~ the degree ~~ hon~n~ between paper fib~r~
and acçordingly increa~e the dry ~nd the wet ~trength propertIe o~ p~per and pa~erboard The water-soluble polymers of tllis invention co~inin~ a polyhydric alcohol ~uch as ~orbitol in the backbone o~ th~ }~olymeric molecule are preferably tho~e wherein the polymer bac~bone coT~pri~e~ polyhydric ~l~ohol~
~nd an alkyl~;ne such a~ nines or tri~lne~, diacids, ~lyoxal, citric acid or fo~maldehyde.
a5 In addition to s~rbi~ol, polyllydric alcohol~ havinsl f rom 2 to 6 carbon ~tomc may be employed a~ a I -nr n~_ric polyol, includin~ mannltol and ethylerle glycol.
riore specifi~ally, th~ pre6ent in~ention i8 directed ~T BY:ATT~RI~EYS AT L~W TH~ 2PJ-~A oi2~ 436i IggA~7 0~72~43 ~6~7 ~1~23~8~4u:~ ~fl.3 to a re~in C!O~I~pO51tiC~n Cont~ n5 frorn a~ut 30% to ~bout.
90gc by weight of a polyhydric a}cohol, copc~ Teriz~d with $rom about 1~ to ~out 7096 by weight of a co~ r)mer. The preferred co-l r ~ner~ copoly~nerized with a polyhydric 5 al~ohc71 ~uch as sorbitol in~lude citric acid, a di~cid, glyoxal, ~onnaldahyde, and an alkyl~mine ~uch as diamine or triamine .
The re~in composition o~ the pre~ent in~rention may be prepared ~ con~rentional COr1~lenFJAtiOn polymerization 10 te~hniq~e~. Re~in ~lurrih~ thereof m~ be pr~3pared ~y diluting the re~in solution~ with wa~er to a re~in concentration o$ typically le~ than al~out 19i ~r weight.
The dll ~te ~olution i8 added to the pulp 51u~ry in an arnount to proYide ~rom about 0.1% to abou~ 59~ by weight of 15 the re~in based on d~y paper fiber. The p}l of the ~olution can be redu~ed by ~he ad~ition of a mineral or organic ~cid to le~s than abou~ 3 to i~crea~e the reacti~ y o~ the re~in, i~ de ired.
To realize the maximum potential of ~he reein 20 ~ompo~ition e:~ thie inven~-ion, control o~ ~he proce~s variables i~ i~ortant. For ~ rle, best resulte a~e obtA;nPfl when the re~in c!o~po~ition~ are added to the paper pulp a~ the wet-end during the pa;?er~naking proce~s.
However, ~he re~in compo~itions may a$so be added to the ~5 paper pulp at the ~i2e pres~.
The fo~lowing exan~ple~3 illustrate th~ prepa~tion o resin ~ompositione wit~in thi~ in~ention and their use ~s dry ~trer~th paper additi~e~, but are not inten~l~d to be S~IT BY:ATTORNEYS AT LAW TH~F; 8-28-~A Oi2nla436j ~T99~7 og~o2443 66i37~ 6132328dAO;J~ 8~15 '' "' ¢~ ~3 limitation~ thereof.

~xa~le 1 A 1500 ml rourld bottorn rea~tion flask wa8 ch~rged with about 670.32 gsam~ of ~orbitol and about 375.~8 gram~ of 5 diethyl'criamine. A nitrogen sparge wa6 st~rt~d and th~
fla3k conten~ were heated to 155~C under a slight ~acu~lm for about 10 hour~. The re~ul~ing polymer had a solids content of ~out 50~,~wt, and B Brookf~eld vielc09ity ~n~.
spindle, 2~ rpm ~ 25~c~ of about 15 cp~.

1~ Exam~le ~
A 1500 ml ro~d bottom reaction flask wa8 charged wich a~out 489.83 ~ram~ of sorbitol, ~bout 390.17 gram~3 of 40~
g}yoxal in wa~er atld about 220 gram~ o~ water. The pH of the mix'cur6~ was ad~u~ed to abou~ 2 O and ~he fla~k 15 con~ents was heated to about 9~~C After about 5 hour~ of heating, additional glyoxal wa~ added to the fla~k to . provide abou~ 2 ~nol~ of glyoxal per mole of sorbitol. The.
reaction mixture was heated an additioTlal three hour~.
visco~ity o~ the rea~tion mixtu~e did not increaae, thua 20 about 20~ gran~ of D~qS0 was ~dded to the fla~k and full vacuu~n was applied eo remove the wate~ while reducing the flask temperature to about 650c~ Afte~ a~out 15.5 hour~, viscoE3i~y increaxed from about 408 to about 5,208 cp~ and the ~eaction wao ~topped.

SE~T sY:ATTOR~EYS AT LAW TH&F; 8-~8-~A a22-436i 1997-09-02 61~328~4~;X g~1 A 1500 ml round bot~om rea~tion fla~k wao charged with about 46~ . 76 gram~ of aorbi~ol, about 33 0 . ~4 gram~ of ~:itric acid, about 200 gram~ o~ water, ~nd about 0 . 8 gr~m 5 of mQthane sul~onic a~id (MSA) ~ a catalyst . The f l~k cohtents wa~ hoated to about 140~C under about 24 in~hes o~
Yacuum to ~e.,~v~ th~ water. Af~er a}:out 1 hour, abollt 300 grams o~ water was added to th~ flaek and the ~olution wa~
neutralized ~o Zl pH of about 7 . O .

10ExamDle 4 A 1500 ml round bottom reaction ~ lc was char~ed with - a}~out 5~1. g2 gram5 of 50r~1itO~ bou~ 208 . 08 grams ~
citric acid, a~out ~0 gra~ of water and ~bou~c 0 . ~ gram of MSA cataly#t~ T~e ~lask content~ was heat~d to about 120CC
15 for abou~ 8 hours unde~ ~tACUUttt, then neutralized to a pH of about 7 . O and ~olu}~ilized in DMSO.

Exa~ple 5 The re~in ~omposition~ prepared in ~x~mpl es 1 to ~~
were evalua~cecl for d~y ~treng~ch propertie~ an~ c~ornE~ared 20 with ~tar~:h and a blank a~ follow~. ~ deinked, recycled pulp ~lur~y cont~in~ a~ou~ 3.~6/wt solids WJI~3 diluted to about O . 5%~wt ~olid3~ A do~age of a~out 1~ pounds of the re~in co~npoeition of Examples 1 to 4 or starch per ~or~ of pulp ~lu~ olids on a dry paper weight ~aBi~ Wa.B added to ~5 about 1, oOo ml aliquot~ ~f the pulp slu~ry. After mixin~, SENT BY:ATTORNEYS AT LAW TH~F: 8-2~-~A 02214367 1997 09-02 61~3~8440.#1~15 . ~"' '~

the 1, Ooo ml aliquot~ were added to an ~ inçh ~are Noble-an~ Woods h~nd~eet mold to make a 5 gram c~.ren d2~r hA~ h~et. The ~heet~ were pros~ed on a roller felt pre~
and dried ~n a felted dryer. The sheet~ were cured for abou~ 15 minute~ a~ out 105~C and then cut into 1" x 4"
s~rips. r~ry terl~ile stren~th wa~ mea~ured on the s~rips u~ ing a Thwing-Albert electronic tensile 'cester . A~
indicated A~ove r teGt ~3trip~ we~ al~o prepared co~t~ ; n~
10 poun~ per ton paper o~ 6tarch, a ccnventional dry ~trength ad~itive, ard blanlc te~t strip~ contA-nin~ no dry ~treng~h addit~ve. The te6t re~ult~ ~re sh~wn belo~ in Table I. The performan~e of 'che ~esin colnpo~itions i~
expres~ed a~ a pt~rc~tage increase over the dry strength o~
handshee~ mad~ w~thou~ additi~e~.
Table I

Dry Strength Re~in ~ry Ten~ile !'6 Increa~e p~3i Stre~ th E~a~le 1 27 . 5 13 .
Exarnple 2 27 . 0 8 . ~
Example 3 27 . ~ 12 . 5 Example 4 ~6.7 7.7 S~arch 24 . 5 0 31ank 24 . 8 0 It cz~n l~e ~een from the teet r~ult~ showrl in T~ble I
t~at the re~in ~~ ~ositions of ~xamples 1 to 4 all pro~ided 25 a ~ub~tantial improv~ment in ~lry strength propertie~ t~
paper f iber .

S~T BY:ATT0R~EYS AT LA~ Tff&F ; 8-28- ~ 022l4367 l997-09-02 ~13~32844~:#11~1a .
',) ~ xamnle 6 ..
To ~ ~leached pulp alurry containing ~bout 3.6~ by weight solid~ w~ adde~ ~ dosage o~ about 8 pound6 of Fib~a~on 33 Ipolyaminoamide-ePichlorohYdrin resin, S available ~rom H~nkel Corporation, P~nbler, PA~ per ton of pulp ~lurry 80lids. Tha ~ixture wae dilut~d to about 0.S4 by weight pulp slurry ~olid~, and divided into l,OG0 ~l aliquot6. ~o e~ch aliquot was ~dded a do~age of about 8 pound~ of th~ re6in compo~i~ions of Examples l, 3 ~nd 4 per ~on o~ pulp paper solid~ on a dry papeL weigh~ ba~is.
After mixing, the l,000 ml aliquot~ were adde~ to an ~ inch ~quare ~oble and Woodx ~n~#heet mold to m~ke a 5 ~ram o~ren dry hand~heet~ The ~heets wer~ preesed on a roller felt pre~s and dried on a ~elted dryer. The ~heet~ were cured ~or about 15 minute~ at about 105~C and then cut into 1" x 4" ~t~ps~ Wet and ~ry ten~ile ~trength was mea~ured on the strip~ usi~g a Thw~ng-Albert electronie ten~ te~ter.
The te~t result~ ax~ ~hown below in Table II.
~a~le II

R~in ~mroe~tion Dry Teneile S Increase Dry pei Stren~th Bl~nk 43.~ ~~~
Fibrabon 33 51-~ 19 07 Example 1 5~.3 30.g3 ~xample 3 58.9 36.sB
~xample 4 57.6 33.95 It c~n ~ ~een from ~he te~t r~ults ~ho~n in T~ble II
tha~ the resin composition~ of Example~ l, 3 and 4 all SENT By:ATToR~Ey~ AT LAW TH~; ~-2~-~ '02il'14~3U6i lTgHg.~7F og~72~543 ~37~ ~13232~440;~12~15 O

provided a sub~tantial improvemen~ in dry strength.
propertie~ to papex ~iber.

Claims (15)

1. A resin composition comprising a water-soluble polymer molecule wherein the backbone of said polymer molecule contains a polyhydric alcohol and a co-monomer selected from the group consisting of an alkylamine, diacid, citric acid, gloxal, and formaldehyde.

2. A resin composition as in claim 1 wherein said polyhydric alcohol contains from 2 to 6 carbon atoms.

3. A resin composition as in claim 1 wherein said polyhydric alcohol is selected from the group consisting of sorbitol, mannitol and ethylene glycol,

4. A resin composition as in claim 1 wherein said alkylamine is selected from the group consisting of diamines and triamines.

5. A resin composition as in claim 1 comprising from about 30% to about 90% by weight of said polyhydric alcohol and from about 70% to about 10% by weight of said co-monomer.

6. A resin composition as in claim 5 wherein said polyhydric alcohol comprises sorbitol.

7. The method of improving the tensile strength properties of paper comprising adding to paper stock a resin composition in an amount sufficient to improve said tensile strength properties, said resin composition comprising a water-soluble polymer molecule wherein the backbone of said polymer molecule contains a polyhyric alcohol and a co-monomer selected from the group consisting of an alkylamine, diacid, citric acid, glyoxal, and formaldehyde.

8. A method as in claim 7 wherein said polyhydric alcohol contains from 2 to 6 carbon atoms.

9. A method as in claim 7 wherein said polyhydric alcohol is selected from the group consisting of sorbitol, mannitol and ethylene glycol.

10. A method as in claim 7 wherein said alkylamine is selected from the group consisting of diamines and triamines.

11. A method as in claim 7 wherein said resin composition comprises from about 30% to about 90% by weight of said polyhydric alcohol and from about 70% to about 10% by weight of said co-monomer.

12. A method as in claim 11 wherein said polyhydric alcohol comprises sorbitol.

13. A method as in claim 7 wherein said resin composition is added to said paper stock in an amount of from about 0.1% to about 5% by weight based on the weight of dry paper fiber.

14. A method as in claim 7 wherein said resin composition is added to said paper stock at the wet-end during a papermaking process.

15. A method as in claim 7 wherein said resin composition is added to said paper stock at the size press during a papermaking process.