Note: Descriptions are shown in the official language in which they were submitted.
21 94733
ADHESIVE COMPOSITIONS AND ADHESIVE TAPES COMPRISING
ZWITTERIONIC COPOLYMERS, AND NOVEL ZWITTERIONIC COPOLYMERS
The lnventlon relates to adheslve composltlons
comprislng zwltterlonlc copolymers, lncludlng repulpable
adheslve composltlons, and adheslve tapes made wlth such
composltlons. Some of the zwltterlonlc copolymers are novel.
Adheslve composltlons, such as pressure-sensitlve
adheslve (PSA) composltlons, commonly contaln an adheslve
polymer together wlth a tacklfler or plastlclzer. The
adheslve polymer provides coheslon and the tacklfler or
plastlclzer lncreases tack.
Adheslves are useful ln a wlde range of
appllcatlons and lnclude PSAs whlch are used ln labels,
packaglng masklng tapes and protectlve coverlngs. Further,
pressure sensltlve adheslve composltlons whlch are water-
dlsperslble are used for fastenlng cloth on mammallan body
coverlngs and ln papermaklng and prlntlng operatlons. In
papermaklng they may be used, for example, to spllce the end
of one roll of paper to the beglnnlng of another roll.
In papermaklng, ln partlcular, lt is deslrable that
the adhesives used are repulpable. That is, they can be left
wlth the paper to be repulped wlthout lnterferlng wlth
subsequent papermaking processes and are free of components
which would blemlsh the flnal paper product. To be
repulpable, such adheslves should be water soluble or water
dlsperslble.
The current trend in papermaklng is away from acid
processing condltions toward alkallne processlng condltlons
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60557-4986
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- 21 94~33
and toward an increased use of calcium carbonate filler.
Conventional repulpable adhesives are usually less suitable
for such alkaline condltlons. Further, those adheslves whlch
mlght be sultable, tend to react wlth the calclum lons of a
calclum carbonate filler to form agglomerates which decrease
the dispersablllty of the adheslve copolymers.
Adhesives used for spllclng in the paper industry
may be sub~ected to elevated temperatures under high shear
forces, for example in supercalender applicatlons. Any
sllppage, even fractlons of a mllllmeter, may lead to
blocking and subsequent web breakage. A high cohesive
strength is deslrable to wlthstand hlgh pressure and heat, to
resist lateral adhesive flow or "oozlng" (which would result
in sllppage) and to reslst adheslve loss by penetration into
the paper or "bleedlng". Further, an adhesive for use in
papermaklng ls preferably repulpable under a varlety of pH
condltions ~both alkallne and acldlc).
Accordlng to one aspect of the present lnvention
there ls provlded an adheslve composltlon comprising a
zwltterlonlc copolymer and a zwltterlonlc plastlclzer or
tackifler.
Accordlng to a further aspect of the present
invention there ls provlded a repulpable adheslve tape
comprlslng a repulpable backlng havlng coated thereon an
adheslve composltlon comprlslng a repulpable zwitterionic
copolymer.
The zwitterionic copolymer comprises a component
derlved from a zwltterlonic monomer together wlth a component
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60557-4986
21 94733
or components derlved from a hydrophobic or hydrophillc
monomer or a mlxture of components derlved from hydrophoblc
and hydrophilic monomers.
The zwitterionic monomer must be one which is
copolymerlzable with any other monomer used. The
zwitterlonic monomers of the present lnventlon include
betaines. Mixtures of zwitterionic monomers may be used.
Suitable betalnes lnclude ammonlum carboxylates,
ammonlum phosphates and ammonlum sulphonates, preferably
ammonlum sulphonates. Preferred betaines are those of
formulae
R6 R8
RS IN -(CH~z Z ~ ~ N - (CH~ - Z
~ a~
in whlch R5 ls a group containing a carbon-carbon unsaturated
bond such as (meth)acryloxy-(C2 4)alkyl, (meth)acrylamldo-
(C2 4)alkyl or (C2-C6)alkenyl, R6 and R7 are each Cl 4 alkyl,
(C2-C6)alkenyl, or (CH2)nOH ln whlch n ls 2, 3 or 4, R8 ls
(C2-C6)alkenyl, z ls an integer of 2-4 and Z~ is S03~ or
C02~. Preferably R is Cl-C4 alkyl, Z~ ls S03~ and z is 3.
Partlcular zwltterlonlc monomers which may be
mentioned are N-(3-sulphopropyl)-N-methacryloxyethyl-N,N-
dimethyl ammonium betaine; N-(3-sulphopropyl)-
N-acryloxyethyl-N,N-dlmethyl ammonlum betaine;
N-(3-sulphopropyl)-N-methacrylamldo-propyl-N,N-dlmethyl
ammonium betalne; l-(3-sulfopropyl)-2-vlnyl-pyrldlnlum
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60557-4986
21 94733
betaine; N-(3-sulphopropyl)-N,N-diallyl-N-methyl ammonlum
betalne; and N-(3-sulphopropyl)-N-allyl-N,N-~lmethyl ammonlum
betalne.
Particularly preferred zwitterionic monomers are
N-(3-sulphopropyl)-N-methacryloxyethyl-N,N-dlmethyl ammonium
betalne and N-(3-sulphopropyl)-N-acryloxyethyl-N,N-dlmethyl
ammonlum betaine. N-~3-sulphopropyl)-N-methacryloxyethyl-
N,N-dimethyl ammonlum betaine is commerclally available from
Rashlg AG, Germany. N-(3-sulphopropyl)-N-
acryloxyethyl-N,N-dlmethyl ammonlum betalne may be prepared
by condensatlon of N,N-dlmethyl amlnoethyl acrylate with
1,3-propanesultone. This latter betaine monomer may also be
prepared by the addition of N,N-dimethyl amlnoethyl acrylate
to the condensation product of epichlorohydrin and sodium
bisulphite.
Generally the zwitterlonic monomer will comprise
from about 10 to about 50 mole % of the monomer mlxture used
to prepare the copolymer, preferably about 10 to about 20
mole %. The balance of the monomer mlxture wlll be a
hydrophobic monomer, a hydrophlllc monomer or a mlxture of
such monomers.
The hydrophoblc monomer must be one which ls
copolymerlzable wlth the other monomers of the copolymer. A
comblnation of different hydrophoblc monomers can be used.
The hydrophoblc monomer may be an acryllc or methacryllc
ester of a non-tertlary alcohol, whlch alcohol has from 1 to
14 carbon atoms, preferably from 2 to 12 carbon atoms. It ls
preferred that the non-tertlary alcohol ls an alkanol.
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60557-4986
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Suitable alkanols to form the ester are alkanols such as
ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol,
1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol,
l-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-
methyl-1-pentanol, 2-ethyl-1-butanol, 3-methyl-1-pentanol,
2-ethyl-1-butanol, 3,5,5-trimethyl-1-hexanol, 3-heptanol,
l-octanol, 2-octanol, lso-octanol, 2-ethyl-1-hexanol,
1-decanol, l-dodecanol, l-tridecanol and 1-tetradecanol.
Preferred hydrophoblc monomers are the esters of
(meth)acryllc acid with butyl alcohol, lso-octyl alcohol or
2-ethyl-1-hexanol or a comblnation thereof.
The hydrophoblc monomer can range generally from 0
to about 85 mole % of the monomer mixture used to prepare the
copolymer, more preferably from about 50 to about 75 mole %.
Generally a higher content of hydrophobic monomer will reduce
water-dispersibllity of the final copolymer.
The hydrophllic monomer must be one which is
copolymerizable with the other monomers of the copolymer.
The hydrophilic monomer may have hydroxy, alkoxy, or amide
functional groups. Examples of suitable hydrophilic monomers
are 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-
hydroxybutyl acrylate, methoxyethyl acrylate, ethoxyethyl
acrylate, ethoxyethoxyethyl acrylate, propoxyethyl acrylate,
propoxypropyl acrylate, butoxyethyl acrylate, butoxypropyl
acrylate, Carbowax* 750 mono-acrylate, Carbowax* 550 mono-
acrylate and acrylamide. A mixture of different hydrophilic
monomers may be used.
* Trade-mark
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60557-4986
2 1 ~4 733
The hydrophlllc monomer can range generally from 0
to about 50, preferably up to about 20 mole % of the monomer
mixture used to prepare the copolymer. Generally a hlgher
hydrophlllc monomer content wlll lncrease the
water-dlsperslbillty of the copolymer.
Some of the zwltterlonlc copolymers are novel.
Thus accordlng to another aspect of the present
lnventlon there ls provided a zwltterionlc copolymer
comprlslng:
(1) a unlt derlved from (a) N-(3-sulphopropyl)-N-
methacryloxyethyl-N, N-dlmethyl ammonlum betalne, (b) N-(3-
sulphopropyl)-N-acryloxyethyl-N,N-dlmethyl ammonlum betalne
or (c) a comblnatlon thereof, and
(2) a unlt derlved from a comonomer copolymerizable
wlth component (1), wlth the provlso that when component (1)
ls other than the comblnatlon of (a) and (b), then the
comonomer (2) ls at least one member selected from the group
conslstlng of 2-(2-ethoxy)ethoxyethyl acrylate and 2-
butoxyethyl acrylate.
In some partlcular embodlments, the copolymer
comprlses:
(1) N-(3-sulphopropyl)-N-methacryloxyethyl-N,N-dlmethyl
ammonlum betalne or N-(3-sulphopropyl)-N-acryloxyethyl-N,
N-dlmethyl ammonlum betalne and (2) 2-(2-ethoxy)ethoxyethyl
acrylate or 2-butoxyethyl acrylate; a comblnatlon of (1)
unlts derlved from (l)(a) N-(3-sulphopropyl)-N-
methacryloxyethyl-N,N-dlmethyl ammonium betalne, (l)~b)
N-(3-sulphopropyl)-N-acryloxyethyl-N,N-dlmethyl ammonlum
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60557-4g86
2 1 94733
betaine and (2) a further comonomer copolymerizable with
(l~(a) and (l)(b); N-(3-sulphopropyl)-N-methacryloxyethyl-
N,N-dlmethyl ammonium betaine and 2-(2-ethoxy)ethoxyethyl
acrylate or 2-butoxyethyl acrylate; a comblnation of unlts
derlved from (l)(a) N-(3-sulphopropyl)-N-methacryloxyethyl-
N,N-dimethyl ammonlum betalne , (l)(b) N-(3-sulphopropyl)-N-
acryloxyethyl-N, N-dlmethyl ammonlum betalne and (2) a
comonomer selected from the group conslstlng of 2-(2-
ethoxy)ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2-
hydroxyethyl acrylate, 2-ethylhexyl acrylate and mlxtures
thereof.
In formulatlon of the adheslve copolymers, several
dlfferent monomers can be comblned, each selected to
contrlbute some deslred property (such as polarity or water
solublllty). Further, the polymerlsation process may be
varled to modlfy propertles of the copolymer product. Such
process varlatlons, as known in the art, can determine
whether the copolymer formed ls linear, branched or
core-shell. Sultable processes include batch, seml-batch,
and pre-emulslflcatlon processes. Preferred processes are
seml-batch or pre-emulslflcatlon processes wlth starve feed
of the monomers.
An example of a sultable reactlon mlxture to
prepare the copolymers ls from about 30% to about 40%, of the
total welght of the reactlon mlxture, of monomers, up to
about 2.0% of a chaln transfer agent, an lnltlator and from
about 1% to about 2% of a surfactant, preferably about 2%.
It is partlcularly preferred to use a combinatlon of nonionic
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60557-4986
2 1 94733
surfactant and lonic surfactant. The chain transfer agent
may be used to modlfy propertles such as shear strength, heat
resistance and water solubility or dlspersibility of the
product. For example, a copolymer havlng satlsfactory
adhesive properties but lacking satisfactory water solubility
or water disperslbillty, may be rendered more water soluble
or dlspersible by increasing the quantity of chain transfer
agent ln the reaction mixture during polymerizatlon and
formation of the copolymer.
Polymerization may be effected by dissolving or
dispersing the monomers in deionized water at a concentration
of about 30% to about 40% by weight to pre-emulsify them.
0.3% of the surfactant is added to the reaction vessel with
the remainder added to the monomer mixture. For a general
procedure where the polymerization ls conducted ln a reactlon
volume of approximately 1 liter, the initiator is dissolved
in about 30 ml of deionized water and 5 ml of this initiator
solution ls added to the reactlon vessel. When a chaln
transfer agent ls used, it is also added to the reaction
vessel. The contents of the reaction vessel are heated to
about 60 to 80~C to form free radicals. A portion of the
pre-emulsified monomers (about 20 to about 30 mL) is fed into
the reaction vessel. After about 5 minutes, polymerization
is initiated. The monomers and the initiator are fed
simultaneously and continuously into the reaction mixture
dropwise until all the monomer and initiator have been added
to the reaction vessel. The reaction is allowed to proceed
for about 4 hours.
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21 94733
When the reaction is complete, the resulting
copolymer solutlon ls cooled to room temperature and flltered
to remove any coagulum. If other compounds are to form part
of the adhesive composition, such as plasticlzers or
tacklfiers, they may be added either before, during or after
the polymerizatlon process. The resultlng aqueous, pressure
sensitive adhesive composition typlcally comprlses from about
20% to 50% by welght sollds.
When an initiator is used whlch generates acld
durlng the polymerlzatlon, such as persulfate lnltlators, it
is customary to neutralize the final copolymer emulsion.
Neutrallzatlon can be accompllshed wlth, for example,
butyldlethanol amlne or metal carbonates. Such
neutrallzatlon reduces corroslveness of adheslve formulatlons
prepared wlth the copolymers.
The chaln transfer agents may be water or oll
soluble. Up to 5%, preferably from 0.5% to 1%, based on the
total welght of the monomers, of the chaln transfer agent may
be used. Typical chain transfer agents include
mercaptoacetic acld, mercaptoethanol,
3-mercapto-1,2-propanediol, A-189 (available from Unlon
Carblde) and l-dodecanethlol.
The inltiator is typlcally used at a level of 2%,
preferably 0.5 to 1% by welght based on the total welght of
the monomers. The lnltlators may be oll or water soluble.
Thermal, redox, or UV lnltlator systems may be used.
Suitable initiators include potassium persulfate and
4,4'-azobls(4-cyanovalerlc acld).
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60557-4986
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The surfactant ls used in an amount of up to 5%,
preferably from 1 to 2% by welght, based on the total weight
of the monomers. The surfactant may be anlonic, nonionic or
a comblnatlon thereof. Many surfactants are commerclally
avallable. For example, alkylphenol ethoxylates are avallable
under the Tradename Igepal CA or Igepal CO. Rhone-Poulenc
offers the followlng surfactants: phosphate esters under the
Tradename Rhodafac; sulphonates under the Tradename Rhodacal;
alkyl sulphates under the Tradename Rhodapon; amphoterlc
surfactants under the Tradename Abex; and ethoxylated
polyoxypropylene block copolymers under the Tradename
Antarox. Henkel offers a surfactant under the Tradename
Disponil AES-21 whlch ls an alkylphenol ether sulphate sodlum
salt.
The presence of the zwltterlonlc component ln the
copolymers means that cross-llnklng agents ~whlch are often
added to pressure-sensltlve adheslve copolymers to lmprove
coheslve strength and heat reslstance) are not always
requlred slnce the zwitterlonic functlon provldes some lonlc
cross-llnklng.
The use of a cross-llnklng agent may be
advantageous to lmprove heat reslstance or coheslve strength.
However, lf a water soluble or water disperslble copolymer ls
requlred, such as a repulpable copolymer for papermaklng, it
should be noted that increaslng cross-linking reduces
repulpabillty and that lf there is too much cross-llnklng the
copolymer wlll not readlly dlsperse under the condltlons
needed for repulplng ln a papermaklng process. Up to 2% by
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60557-4986
2! 94733
weight, based on the total welght of the monomers, of a
cross-llnking agent may be used. If a cross-llnklng agent ls
used, a preferred range ls from 0.5 to 1% based on the total
weight of the monomers. Sultable cross-llnklng agents
include metal chelates, epoxldes, azlrldlnes, melamlne
formaldehyde resins and polyamlde eplchlorohydrlns.
Generally the zwltterlonlc copolymers are water-
dlspersible or water soluble and can be used as an adhesive
component, wlth an approprlate tacklfier or plasticizer, of
repulpable PSA compositions. Some of the zwitterlonic
copolymers may need some additional modificatlon to be
sultable for repulpable adhesive composltlons. For example,
as mentioned above, chaln transfer agents may be added during
polymerization to reduce the molecular welght of the final
copolymer and thus increase the water solubllity or
dlsperslbllity.
Plasticlzers and tackifiers are generally added to
the adhesive copolymers to form adhesive compositions.
Conventional tackiflers include polysaccharide gums, roslns,
rosln derlvatlves (such as Tacolyn 98 avallable from
Hercules), alkyl/aryl hydrocarbon resins and derivatives, and
petroleum-aliphatic resins. Conventlonal water dlsperslble
plasticlzers include polyoxyethylene alkylphenyl ether
phosphates, polyoxyethylenealkyl ether phosphates,
polyethyleneglycolmonophenyl ethers,
octylphenoxypoly(ethyleneoxy) ethanols and
nonylphenoxypoly(ethyleneoxy) ethanols.
In vlew of the zwltterionlc nature of the adhesive
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60557-4986
~ 1 94 733
copolymers, zwitterlonic tackifiers and plasticizers, such as
those disclosed in applicant's copending applicatlon
(attorney docket No. 60557-4987, hereby lncorporated by
reference), have been found to be most suitable.
Such zwitterlonic tackifiers and plasticizers
include the following compounds of formula I
R2 R4
R - IN -(cH2)~ ~EI-(CH2)y -Z (I)
wherein
R1, R2 and R3 are each alkyl, hydroxyalkyl,
aminoalkyl or aryl which may be lnterrupted in the alkyl
chaln by one or more oxygen atoms,
R4 is H or OH,
Z~ ls CO2~ or SO3~,
x and y are each 0, 1 or 2 provided that the sum of
x and y is less than or equal to 4 preferably the sum of x
and y is less than or equal to 3.
Preferably the alkyl groups ln the above moleties
of R1, R2 and R3 have from 1 to 12 carbon atoms, more
preferably from 1 to 8 and in partlcular from 1 to 2 carbon
atoms.
It is also preferred that R2 and R3 are the same
and R1 ls dlfferent.
Partlcular examples of such tackifiers and
plasticizers are:
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60557-4986
- 21 94733
OH CH3 OH
4Hg-O-CH2-CH-CH2- 1 -CH2-CH-CH2-SO0
CH3
N (2_hYdrV~CY 3_S~ VY~1)-N,N dimethY1-N-(3-bUtY10AY-
2-L~J~V~O~ betaine
OH CH3 OH
C8Hl7-O-CH2-CH~H2- 1 ~ -CH2-CH-CH2-SO3
CH3
N-(2-hYdrV~CY-3-SU1PI~V~ 1)-N,N-J~ 1-N-
(3-OCtY1O~Y-2 ~V~Y,VY~V betaine
CH3 OH
HO-CH2-CH2-CH2- IN -CH2-CH-CH2-S03
CH3
N-(2-~ r~A~-3-sulpl~ y,l)-N,N-di~l-
N-(3~ vA,~,~l)-~mm~ b~
OH CH3
HO-CHz-CH-CH2-IN -CHz-CH2-CH2-SO3
CH3
N-(3 L ~h~VY~1)-N,N~1~m~ ~1-N-(2,3-
d;h~O~Y~ ne
2 0 H~-CHrCH2-~-CHrCHrN~9 -CHrCHrCH2-S00
CH3
N-(3 ~ )-N-N dime~YI-N-2-(2-
~A,~ ~thyloAy)e~y~ . . betaine
CH3
HO-CHrCHr IN~ ~HrCHrCH2-SO30
CH3
N_(3_;~ >~VY,1) N,N dim~yl N
(2-1~ ~A~ 1) a~--- ' ~ betaine
60557 -4986
- 21 94733
CH2CH20H
CH3-CHrCH2-CHr~ -CH2-CHrCH2-SO3 tBU diEtOH
CH2CH20H
N-(3 ~ v~>~v-N~N-di(2-h~d~v.~,lh,~l)-N-butyl a~ . n ~ . betai~e
CH2GH2OH
CH3- IN~3 -CH2-CH2~HrSO3~ IMe diE~tOH
CHzCH20H
N-(3-slllr~ plolJ,I)-N,N di(2-l~ A~,thyl)-N-me~yl ~ ilTm be~ine
CH3
HO-CH2-CH2-CH2- 1 -CH2-CH2-CH2-SO3 [diMe l-prOHl
CH3
N-(3-s~ h-~ol~l)-N~N~l;~ -N-(3-h~hvA~ m betaine
OH CHrCH2-OH
CH3-CH-CH2- IN -CH2-CHrCHrSO3 [diEtOH 2-prOHl
CHrCH2-OH
N-(3 ~ pt~ l)-N~N-di(2-h~LvA~hyl)-N-(2-hyd
- ~ m be~ine
CH2CH20H
CH34cH2)r 1 -cH2-cH2-cH2-so3
CH2CH20H
N-(3~ul~ho~,1)-N,N di(2-hydtoAyethyl)-N oc~yl ammonium betaine
CH2CH20H
CH3-(CH2)S- IN -CH2-CHrCHrSo/33 v~
CH2CH20H
N-(3 sul~ -N,N di(2-hyd~oyethyl~N-he~yl ~ 5~ betaine
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60557 -4986
21 94733
Of the above, N-(2-hydroxy-3-sulphopropyl)-N,N-
dimethyl-N-13-hydroxypropyl)-ammonlum betalne, Bu dlEtOH, Me
dlEtOH, diME l-prOH and dlEtOH 2pr-OH are preferred.
As ls known, varlous other compounds can be added
to lmprove the characteristics of the final adhesive
formulation. Compounds such as PVP K-30 and PVP K-90
(commercially avallable polyvlnylpyrrolldones of molecular
welght 57,500 and 1,270,000 respectlvely) can be added to
improve the strength and toughness of the base adhesive
copolymer. FC-171 (a fluorochemical) can be added, for
example as a 10% aqueous solution, to improve wetting
characterlstlcs of the flnal adheslve formulatlon.
The tackifiers and plasticizers are added to an
adheslve polymer, together wlth any other addltlves, to form
an adhesive composition. Whilst the amounts used may vary
dependlng on the nature of the components of the adheslve
composltlon, generally they are effective when added at a
rate of 30 to 100 parts by welght based on 100 parts by
welght of the adhesive polymer. Such adhesive compositions
may be prepared in the usual way by blendlng or mlxing. The
tackifiers and plasticizers may be added, for example, to an
aqueous emulsion of the formed adhesive polymer, or may be
added to a monomer feed stream before formation of the
adhesive polymer.
A pressure sensitive adhesive tape may be made by
applylng the pressure sensltive adhesive composltlon to one
or more surfaces of a substrate backlng to form a one-sided
or double-slded tape. If the tape ls to be repulpable, the
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60557-4986
21 94733
substrate backing should also be repulpable. The adheslve
may be fortifled with a repulpable tlssue for the
construction of double-slded tapes. Sultable repulpable
tlssues may be obtalned from Burrows Paper Corporation.
A release liner may be used to cover and protect
the exposed surfaces of the pressure sensltlve adheslve tape
between manufacture and use. Commerclally avallable release
llners lnclude sillconlzed paper release llners.
Repulpable adheslves may be applied directly to a
substrate, that ls, wlthout any backlng, by means of a brush
or ln the form of a spray or a bead. For example, ln
papermaklng, the PSA may be applied to a paper surface
ad~acent the tralllng edge of one roll and then the leadlng
edge of the next roll may be pressed dlrectly onto the
adhesive thus ioining the edges of the two rolls. When used
wlthout a backlng, the adheslve can be fortlfled wlth flbres
for easy handling. For a repulpable tape, sultable flbres
lnclude celluloslc flbres or polyvlnyl alcohol flbres.
Repulpable PSA formulatlons should adhere to at
least common types of paper such as AKD slzed; paper for
offset prlntlng ("offset"); European bond paper; Canadlan
bond paper; and paper for rotogravure prlntlng
("rotogravure").
It has been found that the use of zwltterionic
polymers ln formulatlng adheslve composltlons may also
provlde the followlng advantages both high tack and low tack
formulatlons may be prepared from a common base polymer;
neutrallzatlon of the polymers may not be required to provide
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60557-4986
21 94733
water dlspersibllity; curing agents may not be needed to give
the polymers heat resistance and cohesive strength; and the
polymers may be formulated into adheslve composltlons whlch
have well-balanced propertles.
Besldes repulpable adheslves for papermaklng the
adheslves and adheslve formulatlons of the lnvention are also
useful for a variety of other appllcatlons such as for
labels, masklng tapes and stamps as well as for vapour
strippable products such as wall paper or other decorative
wall coverlngs.
TEST PROCEDURES
It ls belleved that a brlef explanation of certaln
test procedures will be helpful in understanding the
invention.
Delrin wheel tack test
In thls test, a standard Delrln wheel welghlng 28.8
g wlth dlameter of 8.13 cm ~3.2 lnches), a rlm wldth of 1.9
cm (0.75 lnches), a thickness of 0.16 cm (1/16 inches), a
hollow axle with a dlameter of 1.27 cm (0.5 lnches) and a
length of 3.175 cm (1.25 lnches) ls rolled down a plane
havlng a length of 26.7 cm (10.51 inches) and lncline of 24
degress to a horizontal surface on which the tape to be
evaluated is posltloned, adhesive slde up. The dlstance the
wheel rolls along the horlzontal adhesive surface is measured
in mm, the tack being inversely proportlonal to the dlstance.
For an adhesive formulation for a permanent tape, the
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60557-4986
2! ~4733
distance the Delrln wheel rolls may be around 300 mm or more.
The shorter the dlstance the wheel rolls, the greater the
tack. For example, for the greater tack requlred by an
adheslve formulatlon for a temporary tape, a lower value,
such as 30 mm, mlght be expected.
Repulpablllty
Dlsperslbility is measured by evaluating
repulpabillty accordlng to TAPPl test UM-213. Samples are
prepared by coating 13-24 grains per 24 sq in (0.3 g per 8 sq
ln) of the adheslve or adheslve formulatlon to be tested onto
one side of a backlng strip 20 cm by 2.54 cm (on each slde to
test double faced tape). For double faced tape, one sample
is sandwlched between two 20 cm x 2.54 cm strips of blotter
paper; and for slngle faced tape, two samples are adhered to
blotter paper. The samples are cut into approximately 1.5 cm
squares. To these squares are added a sufficient number of
1.5 cm squares of uncoated blotter paper to make a total of
samples and uncoated blotter paper of 15 g, and all the
squares are placed in a Waring blender with 500 mL of water.
The blender ls run at low speed (approxlmately 15,000 rpm).
After the blender has run for 20 seconds, lt is stopped for 1
mlnute whlle the stock which has splashed up the sldes is
washed back lnto the bottom with a water bottle. The blender
ls again run for 20 seconds, washed down as before, and run
for a final 20 second cycle. The stock ls then removed from
the blender and made lnto a handsheet on a sheet mold. The
sheet ls removed from the mold, pressed between sheets of
- 18 -
60557-4986
2~ 94733
blotter stock for 1.5 minutes in a hydraulic press, dried,
and examined for any particles of unrepulped tape. If no
particles are present, the tape is considered to have passed
the test.
Another method for determining the repulpability of
these products is the PTS Method. In this method the
adheslve or adhesive formulation was coated on akrosil
backing at 13 to 15 grains per 24 square lnches. 2g strlps
of the coated backing were combined with 48 g of European
copy paper to form the samples to be tested. The test is
normally conducted at pH 7, but pH 4 and pH 10 may be used
for a full test to determine repulpability under acidic and
alkaline conditions. The samples are added to 2000 ml of
water and transferred into a standard dislntegrator. The
sample is disintegrated for 10 minutes (+ 30 seconds) with a
rotor speed of about 3000 rpm. The pulp suspenslon ls put ln
a vessel, diluted to a total volume of 10 L and homogenized
for approximately 2 mlnutes. 400 ml samples of the resultlng
homogenlzed liquid are removed to make handsheets. The test
handsheets, so prepared, are vlewed agalnst a light source.
Any defects or transparent spots, caused by non-disperslble
constltuents ln the homogenized liquid used to prepare the
handsheets, are counted and characterized by size and colour.
If no defects or transparent specs are observed,
the formulation used in the sample will be considered
repulpable. If a few transparent specs are observed, the
formulation will be considered "marginally" repulpable. That
is, the substance will be considered water dlsperslble but
-- 19 --
60557-4986
_ 21 94733
not repulpable according to the PTS test used.
These tests do not apply to tape products where the
backing is a polyester film, which does not lend itself to
repulping. Such backings are strong, however, and may be
used in tape constructions, provlded the loosed backing ls
mechanlcally removed.
Unless otherwlse stated, the PTS test method at pH
7 was used for repulpablllty tests ln the followlng examples.
T-Peel Adhesion test
The sample is measured in the cross direction of
the tape. The machine direction in the direction ln whlch
the adhesive is laid down on the backlng as lt ls unwound.
The cross dlrectlon ls perpendlcular to the machlne
direction.
A 1" (2.54 cm) sample of tape is cut in the cross
direction of the tape approximately 8cm long. This sample is
laminated to a slmllar slzed plece of test paper leaving
approximately 2.5 cm un~oined to allow a strip of each layer
of the laminate to be placed ln each of the two ~aws of a
tensile tester. The prepared sample is rolled four times
uslng a 2 kg roller. The sample is allowed to acclimatize
for 1 minute (dwell time) before testing.
For a double-sided tape, the same slze sample ls
laminated between two 1" (2.54 cm) wide strips approxlmately
8 cm long, so that the cross direction of the tape is in the
direction of the long slde of the paper. The sample is then
rolled in the same manner as for testing of a single sided
- 20 -
60557-4986
- 21 94733
tape.
For testlng, the sample is placed in the ~aws of
the tenslle tester. The sample then resembles a "T" havlng
the un~olned ends in each ~aw and the tail of the "T"
horizontal. The ~aws are then separated at a speed of 50
mm/min (2"/min). The force required to separate the ~aws is
the T-peel value and is measured in Newtons/cm (N/cm). The
mode of peel may also be recorded.
Statlc Shear
A static shear test provides information on the
ability of the splice to withstand shear forces in a paper
processing operation. An overlap splice (2.54 cm x 2.54 cm)
is prepared and pressed with a 2 kg roller (4 passes). The
splices are condltioned for 20 minutes to acclimatize them to
the temperature and humidity of the test conditlons, and then
60557-4986
21 94733
~
a 1 kg weight ls suspended from the splice in a vertical
manner. The time in minutes for the splice to fail is
recorded.
Heat reslstance
This test simulates the shear forces encountered by
a paper splice at elevated temperature.
An overlap splice (2.S4 cm x 2.54 cm) is prepared
and rolled twice wlth a 6.8 kg (15 lb) roller. Within one
minute of preparation, the splice ls contacted with a curved
heated surface, which is malntained at 150 C. One end of the
splice is held with a clamp to prevent it from moving during
the test. The other end of the splice is threaded over the
curved surface. A 2 kg weight is attached to this end whlch
is allowed to hang, supportlng the weight. The tlme requlred
for the splice to separate (adhesive shear failure) is then
measured ln seconds. The tlme ls measured from the moment of
first contact with the heated surface. If the splice does
not separate ln 2 minutes, the amount of sllppage ln mm ls
recorded.
ABBREVIATIONS
In the following examples and tables, abbrevlations
used are as follows:
AA stands for acrylic acid;
BA stands for butyl acrylate;
EOA stands for 2-ethoxyethyl acrylate;
EOEOA stands for 2-(2-ethoxy)ethoxyethyl acrylate;
- 22 -
60557-4986
21 94733
IOA stands for iso-octyl acrylate;
MEA stands for 2-methoxyethyl acrylate;
BuOEtA stands for 2-butoxyethyl acrylate;
CTA stands for chaln transfer agent;
AES-21 stands for Disponil AES-21 whlch ls a surfactant;
SPE stands for N-(3-sulphopropyl)-N-methacryloxyethyl-N,N-
dimethyl ammonium betalne;
SP-A stands for
N-(3-sulphopropyl)-N-acryloxyethyl-N,N-dlmethyl ammonium
betalne;
HEA stands for 2-hydroxyethyl acrylate;
EHA stands for 2-ethylhexyl acrylate;
Bu diEtOH, Me diEtOH, diMe 1-prOH and diEtOH 2-prOH refer to
the zwltterlonic compounds obtained by reaction of 1,3-
propane sultone wlth butyldlethanol amine, methyldiethanol
amine, N,N-dimethyl-1-propanol amlne and N,N-dlethanol-2-
propanol amine respectively. The full structures of these
four zwitterionic compounds are glven above.
PREPARATION OF COPOLYMERS
BA/SPE
A 1-litre resin flask was charged with butyl
acrylate (24 g,0.188 mol), SPE (16.8 g, 0.060 mol), Trlton X-
200 (2.9 g, 2% by weight based on monomers, 28% active) and
deionized water (122 mls). The flask was fltted wlth a
mechanlcal stirrer and an argon purge. The contents were
stlrred, heated at 60~C and purged for one hour. Potassium
persulfate (0.397 g, 0.0015 mol) was added and the reactlon
- 23 -
60557-4986
21 ~4733
was continued for five hours. The emulsion was cooled to
amblent temperature. The product was characterlzed by DMA
and elemental analysls.
The above method was repeated varying the mole % of
the two monomers to obtaln a serles of copolymers of graded
zwltterionic content. The mole % of the monomer mixtures
used to obtaln each copolymer is shown below in Table A as
Examples A through I.
TABLE A
Preparation Example BA SPE
A 95 5
B 92 8
C 89 11
D 86 14
E 83 17
F 79 21
G 76 24
H 72 28
67 33
The copolymers obtained, without formulation with
other additives, were then tested for repulpabillty using the
PTS method as described above. The copolymers of examples F,
G, H and I were found to be repulpable without further
modiflcation of the copolymer. The copolymers of examples D
and E showed some small specs and were considered marginally
30 repulpable.
-- 24 -
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2~ 94733
The other copolymers used in the examples were
prepared simllarly to the preparatlon of BA/SPE glven above
by varying the nature and quantity of the monomers.
Examples 1-1 to 1-8
Copolymers were prepared uslng varlous monomers in
combination wlth the zwitterionic monomer SPE. The
copolymers were prepared by batch or pre-emulsification
polymerization.
To illustrate, details of the preparation of
Examples 1-5 and 1-6 are provided. The other copolymers of
Examples 1-1 to 1-8 were obtalned by similar procedures.
Preparatlon of ExamPles 1-5 and 1-6
PreParatlon of Example 1-5
Into a l-lltre reactlon vessel were placed the
followlng monomers: butyl acrylate (27.1 g, 0.21 mol), iso-
octyl acrylate (14.2 g, 0.08 mol), SPE (16.1 g, 0.06 mol) and
2-(2-ethoxy)ethoxyethyl acrylate (7.25 g, 0.04 mol). Trlton
X-200 (4.62 g) and deionized water (194 g) were added and the
flask was fitted wlth a mechanlcal stirrer and purge tubes.
The contents were stirred at 65 to 70~C with purging under
argon for 45 minutes. Potassium persulfate (0.43 g) was
added and the reaction was allowed to proceed for six hours.
- 25 -
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- 21 94733
Preparation of Example 1-6
Into a l-lltre reaction vessel were placed the
following monomers: butyl acrylate (60 g, 0.47 mol), 2-
hydroxyethyl acrylate (4.8 g, 0.04 mol), and SPE (16.8 g,
0.06 mol). Triton X-200 (5.8 g) and deionlzed water (163.2
g) were added and the flask was fltted wlth a mechanlcal
stlrrer and purge tubes. The contents were stirred at 65 to
70~C with purging under argon for 45 mlnutes. Potassium
persulfate (0.212 g) was added and the reactlon was allowed
to proceed for five hours.
Table 1 shows the proportlons of monomers used ln
each of the examples in mole % of the total monomer content
of the polymerization mixture. The monomers BA and IOA are
examples of hydrophobic monomers and EOEOA, HEA and AA are
examples of hydrophilic monomers. The proportions used in
Examples 1 to 8 produced copolymers havlng a hydrophoblc
character.
Table 1 Hydrophobic Copolymers
Exxmple BA IOA EOEOA HEA AA SPE
1-1 55 20 5 20
1-2 52 21 16 11
1-3 55 20 10 15
1-4 20 55 5 20
1-5 55 20 10 15
1-6 82 7.4 10.6
1-7 76.4 5.2 18.4
1-8 80 20
The copolymers of Examples 1-1 to 1-7 were then
used as base adheslve copolymers to prepare adheslve
- 26 -
60557-4986
21 94733
formulations l-lF to 1-7F by addlng tacklflers, plastlclzers,
PVP K-90 and FC-171 ( 10%) and ad~ustlng the pH with
butyldlethanol amlne. The composition and final pH of each
formulatlon ls shown ln Table lF . In each formulation ln
Table lF, "tack 1" was Bu diEtOH, "tack 2" was Tacolyn 98 and
"Plast" was N-(2-hydroxy-3-sulphopropyl)-N,N-dlmethyl-N-(3-
hydroxypropyl)-ammonlum betalne. Besldes the pH values, the
quantltles shown in Table lF are all parts by welght based on
one hundred parts by weight of the base adheslve copolymer.
10 Table lF: Formulations for the Hydrophobic Copolymers 1-1 to 1-7 of Table
CodeTack 1 Tack 2 Plast PVP FC-171 pH
l-lF 10 10 0.05 7.35
1-2F 40 10 0.05 6.78
1-3F 40 11.5 0.05 6.61
1-4F 40 10 0.05 7.68
1-5F 40 10 0.05 7.41
1-6F 60 2 2 0.06 4.51
1-7F 60 2 2 0.06 7.68
The seven formulatlons, l-lF to 1-7F, were tested
on flve types of paper: AKD si2ed; offset; bond (European);
bond (Canadlan); and rotogravure. The tests were: shear
strength; heat reslstance; T-peel; and wheel tack (Delrin
wheel). The test procedures were those descrlbed above. The
results for each formulatlon are shown ln Tables l-lF to 1-
7F.
60557 -4986
2 1 q4 733
Table l-lF ~BA/IOA/HEA/SPE, 55/20/5/20)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
.
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 1226+ 120+ 0.04 300
0.1
Offset 10000 120+ 0.31 247
0.1
Bond (Eur) 1604 120+ 0.04 300
0.1
Bond (Can) 6629 120+ 0.08 300
0.1
Rotogravure 10000 120+ 0.63 42
0.1
Table 1-2F (BA/IOA/HEA/SPE, 52/21/16/11)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 10000 120+ 0.12 300
0.1
Offset 10000 120+ 1.26 300
0.25
Bond (Eur) 10000 120+ 0.12 300
0.1
Bond (Can) 10000 120+ 0.47 300
0.1
Rotogravure 10000 120+ 0.94 104
0.25
- 28 -
60557-4986
-- 21 94733
Table 1-3F (BA/IOA/HEA/SPE, 55/20/10/15)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 1662 120+ 0.08 300
0.2
Offset 10000 120+ 0.83 92
0.15
Bond (Eur) 1507 120+ 0.08 300
0.1
Bond (Can) 5522 120+ 0.16 300
0.1
Rotogravure 10000 120+ 0.87 182
0.25
Table 1-4F (BA/IOA/HEA/SPE, 20/55/5/20)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 740 120+ 0.08 300
0.2
Offset 10000 120+ 0.71 245
0.5
Bond (Eur) 457 120+ 0.08 300
0.4
Bond (Can) 299 120+ 0.16 300
0.25
Rotogravure 10000 120+ 0.98 103
0.3
- 29 -
60557-4986
- 21 94733
Table 1~5F (BA/IOA/EOEOA/SPE, 55/20/10/15)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 421 120+ 0.12 300
0.2
Offset 23630 120+ 0.91 197
0.5
Bond (Eur) 157 120+ 0.20 300
0.4
Bond (Can) 288 120+ 0.43 300
0.25
Rotogravure 10000 120+ 0.98 37
0.3
Table 1-6F ~BA/HEA/SPE, 82/7.4/10.6)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 2988 120+ 0.87 230
0.1
Offset 10000 120+ 1.65 75
0.1
Bond (Eur) 1529 120+ 0.98 114
0.0
Bond (Can) 10000 120+ 1.65 200
0.05
Rotogravure 10000 120+ 0.98 30
0.0
- 30 -
60557-4986
- 2! 94733
Table 1-7F (BA/AA/SPE, 76.4/5.2/18.4)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 263 120+ 0.98 300
0.3
Offset 1504 Failed 2.17 118
Bond (Eur) 243 120+ 1.14 300
0.15
Bond (Can) 486 120+ 1.73 300
0.3
Rotogravure 2550 120+ 0.75 65
0.2
Each of the seven formulations, l-lF to 1-7F, was
tested for repulpablllty uslng the PTS method as descrlbed
above. The formulatlons of Examples 1-2F and 1-7F were found
to be repulpable wlthout further modlflcatlon of the base
adhesive copolymers.
Examples 2-1 to 2-9
Copolymers were prepared uslng various monomers ln
combinatlon wlth the zwltterlonlc monomer SPE or both SPE and
20 SP-A.
To lllustrate, detalls of the preparatlon of
Examples 2-4, 2-5, 2-6, 2-7 and 2-8 are provlded. The other
copolymers of Examples 2-1 to 2-9 were obtalned by slmilar
procedures.
- 31 -
60557 -4986
2 1 94 733
Preparation of Copolymers of Examples 2-4, 2-5, 2-6, 2-7 and
2-8
Preparation of Example 2-4
Into a l-lltre reactlon vessel were placed SPE
(4.39 g, 0.016 mol), SP-A (4.17 g, 0.016 mol), AES-21 (1.70
g), Trlton X-405 (0.62 g), delonlzed water (103 g), and
sodlum carbonate (0.13 g). The contents were stlrred at 70~C
and purged for 20 minutes. Potasslum persulfate (0.32 g) was
dlssolved ln a mlnlmal amount of water and was added ln one
portlon. 2-Ethoxyethyl acrylate (25.7 g, 0.178 mol) was
added dropwlse over 12 minutes and the reactlon was allowed
to proceed for an additional 50 mlnutes.
Preparation of Example 2-5
Into a 250 mL reaction vessel were placed SPE (3.74
g, 0.013 mol), SP-A (3.55 g, 0.013 mol), 2-hydroxethyl
acrylate (2.84 g, 0.02 mol), 2-butoxyethyl acrylate (24.6 g,
0.14 mol), delonized water (105 g), AES-21 (1.77 g), and
Trlton X-405 (0.2 g). The contents were stlrred for seven
mlnutes and sodlum carbonate (0.14 g) was added to the
reaction. The contents were brought to a temperature of
70~C. After purglng for 40 mlnutes the potasslum persulfate
(0.35 g) was added. The reactlon was allowed to proceed for
an additlonal 1 hour 25 minutes.
- 32 -
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2! 94733
Preparatlon of Example 2-6
In a l-lltre reactlon vessel were placed the
followlng monomers: 2-butoxyethyl acrylate (18.23 g, 0.11
mol), SPE (2.62 g, 0.009 mol), SP-A (2.49 g, 0.009 mol),
Trlton X-200 (1.67 g), and deionlzed water (70 g). The flask
was fitted with a mechanical stirrer and purge tubes. The
contents were stirred at 65~C with purging under argon for 1
hour 30 minutes. Potassium persulfate (0.15 g) was added and
the reactlon was allowed to proceed for eight hours.
Preparatlon of Example 2-7
Into a 500 mL reaction vessel were placed SPE (4.48
g, 0.016 mol), SP-A (4.26 g, 0.016 mol), deionized water (125
g), AES-21 (1.93 g), and Triton X-405 (0.24 g). The contents
were stirred for 5 minutes and sodium carbonate (0.16 g) was
added. The contents were brought to a temperature of 70~C.
After purging for 30 minutes the potassium persulfate (0.42
g) was added. 2-Butoxyethyl acrylate (22.81 g, 0.132 mol)
and 2-ethylhexyl acrylate (10.18 g, 0.055 mol) were combined
and added dropwise over 25 minutes. The reaction was allowed
to proceed for an additlonal 52 mlnutes.
Preparation of Example 2-8
Into a 250 mL reaction vessel were placed SPE (4.60
g, 0.016 mol), SP-A (4.37 g, 0.016 mol), deionlzed water (105
g), AES-21 (1.95 g), and Triton X-405 (0.24 g). The contents
were stirred for 15 minutes and sodium carbonate (0.17 g) was
added to the reaction. The contents were brought to a
- 33 -
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21 94733
temperature of 70~C. After purging for 34 minutes the
potassium persulfate (0.43 g) was added. 2-Butoxyethyl
acrylate (9.46 g, 0.06 mol) and 2-ethylhexyl acrylate (24.3
g, 0.13 mol) were comblned and added dropwlse over 20
minutes. The reaction was allowed to proceed for an
additional one hour.
Table 2 shows the proportions of monomers used in
each of the examples in mole % of the total monomer content
of the polymerization mixture. The monomer EHA is a
10 hydrophobic monomer. Monomers MEA, EOEOA, EOA, BuOEtA and
HEA are hydrophilic monomers. The copolymers prepared in
these examples had a hydrophllic character.
Table 2 Hydrophilic Copolymers
Example EHAMEA EOEOA EOA BuOEtA HEA SPE SP-A
2-1 85 15
2-2 90 10
2-3 85 15
2-4 85 7.5 7.5
2-5 7112 6.7 6.7
2-6 85 7.5 7.5
2-7 25 60 7.5 7.5
2-8 60 25 7.5 7.5
2-9 87 13
The copolymers of Examples 2-1 to 2-9 were then
used as base adhesive copolymers to prepare adhesive
formulations 2-lF to 2-9F by adding tackifiers, plastlcizers,
PVP K-90 and FC-171 (10%) and ad~usting the pH with
butyldiethanol amine as was done for Examples 1-1 to 1-7.
The base adhesive copolymers used for formulations 2-lAF and
-- 34 --
60557-4986
2 1 94733
2-3F were prepared by polymerlzing the monomer mixture in
contact with 0.5 parts by weight, based on 100 parts by
weight of the total monomer mixture, of l-dodecanethiol as a
chaln transfer agent (CTA). The composltlon and flnal pH ls
shown ln Table 2F. In each formulatlon ln Table 2F, "tack l"
was Bu diEtOH, "tack 2" was Tacolyn 98, "tack 3" was a
mixture of 87% by weight of Bu diEtOH and 13% by welght of Me
diEtOH, and "plast" was N-(2-hydroxy-3-sulphopropyl)-N,N-
dimethyl-N-(3-hydroxypropyl)-ammonium betaine. Besldes the
10 pH values, the quantltles shown ln the table are all parts by
welght based on one hundred parts by weight of the base
adhesive copolymer.
Table 2F: Formulations for the Hydrophilic Copolymers 2-1 to 2-9 of Table
Code Tack 1 Tack 2 Tack 3 Plast PVP FC-171 CTA pH
2-lF 40 10 0.05 7.65
2-lAF 40 10 0.05 0.5 7.95
2-2F 40 10 0.05 6.18
2-3F 40 10 0.05 0.5 8.53
2-4F 40 0.06 5.31
2-5F 40 10 0.06 3.47
2-6F 40 0.05 8.52
2-7F 40 0.06 4.19
2-8F 40 0.06 4.19
2-9F 70 0.8 0.07 8.22
Each of the formulatlons, 2-lF to 2-9F, was tested
30 on five types of paper: AKD sized; offset; bond (European);
bond (Canadian); and rotogravure. The tests were: shear
strength; heat resistance; T-peel; and wheel tack (Delrin
wheel). The test procec~ures were those described above. The
60557-4986
2~9~733
results for each formulatlon are shown ln Tables 2-lF to 2-
9F.
Table 2-lF (MEA/SPE, 85/15)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 160 120+ 0.08 Not
0.2 Determined
Offset 10000 120+ 1. 5 Not
0.25 Determined
Bond (Eur) 1382 120+ 0.08 260
0.15
Bond (Can) 10000 120+ 0.35 Not
0.25 Determined
Rotogravure 10000 120+ 1.14 200
0.1
Table 2-lAF (MEA/SPE, 85/15)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 974 120+ 0.71 300
0.5
Offset 4032 120+ 0.79 31
0.7
Bond (Eur) 1557 120+ 0.98 300
0.6
Bond (Can) 1542 120+ 1.34 164
0.5
Rotogravure 3904 120+ 0.63 26
0.6
-- 36 --
60557-4986
2 1 94733
Table 2-2F (EOEOA/SPE, 90/10)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 142 120+ 0.12 300
0.5
Offset 4334 120+ 0.94 59
0.15
Bond (Eur) 482 120+ 0.16 300
0.15
Bond (Can) 577 120+ 0.63 205
0.1
Rotogravure 10000 120+ 0.95 41
0.15
Table 2-3F (EOEOA/SPE, 85/15)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 20.7 Failed 2.01 134
Offset 30.9 Failed 2.40 105
Bond (Eur) 24.1 Failed 2.28 300
Bond (Can~ 25.8 Failed 2.20 133
Rotogravure 39.1 Failed 1.97 38
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21 q4733
Table 2-4F (EOA/SPE/SP-A, 85/7.5/7.5)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 74.3 120+ 0.1 300
0.8
Offset 138 Failed 0.51 300
Bond (Eur) 84 120+ 0.08 300
0.3
Bond (Can) 66 120+ 0.16 Not
0.4 Determined
Rotogravure 3562 120+ 0.79 Not
0.0 Determined
Table 2-5F (BuOEtA/HEA/SPE/SP-A, 71/12/6.7/6.7)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 16 120+ 0.06 300
0.0
Offset 5604 120+ 0.51 Not
0.0 Determined
Bond (Eur) 11 120+ 0.12 300
0.0
Bond (Can) 4328 120+ 0.08 Not
0.3 Determined
20Rotogravure 5603 120+ 0.51 300
0.0
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Table 2-6F (BuOEtA/SPE/SP-A, 85/7.5/7.5)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 4260 120+ 2.63 21
0.6
Offset 4260 Failed 2.13 14
Bond (Eur) 4260 120+ 2.20 25
0.6
Bond (Can) 4260 120+ 2.36 17
0.8
Rotogravure 4260 120+ 2.36 24
0.35
Table 2-7F (EHA/BuOEtA/SPE/SP-A, 25/60/7.5/7.5)
Paper Shear Heat T-PeelWheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 35 120+ 0.2 42
0.2
Offset 1632 120+ 0.63 23
0.15
Bond (Eur) 113 120+ 0.39 55
0.1
Bond (Can) 29 120+ 0.43 23
0.1
Rotogravure 1632 120+ 1.1 20
0.0
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Table 2-8F ~EHA/BuOEtA/SPE/SP-A, 60/25/7.5/7.5)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150~C 2kg) N/cm mm
min. sec.
mm
AKD Sized 585 120+ 0.74 70
0.2
Offset 1624 120+ 1.46 23
0.4
Bond (Eur) 1624 120+ 1.02 42
0.35
80nd (Can) 1624 120+ 1.46 21
0.3
Rotogravure 1624 120+ 1.46 16
0.4
Table 2-9F (MEA/SPE, 87/13)
Paper Shear Heat T-Peel Wheel Tack
Strength Resistance
(150 C 2kg) N/cm mm
min. sec.
mm
AKD Sized 192 120+ 0.63 96
0.4
Offset 177 Failed 1.85 25
Bond (Eur) 86 120+ 0.71 86
0.4
Bond (Can) 111 120+ 0.83 43
0.4
Rotogravure 346 120+ 0.79 28
0.6
Each of the formulatlons, 2-lF to 2-9F, was also
tested for repulpablllty uslng the PTS method as descrlbed
above. The formulatlons of examples 2-lF, 2-lAF, 2-2F, 2-3F,
2-4F and 2-9F were found to be repulpable without further
modiflcatlon of the base adheslve copolymers.
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Examples 3-1 to 3-4
These examples demonstrate the effectiveness of
zwltterlonlc tacklflers ln comblnatlon wlth the zwltterlonlc
copolymers. A tacklfier was admixed wlth a copolymer, as
the base adhesive copolymer, obtained by polymerizing SPE and
MEA in a mole ratio of 13:87 (SPE MEA) (see Example 2-9 in
Table 2). Four different zwitterlonlc tacklfiers were used,
as shown ln the first column under the headlng "tacklfler".
These tacklfiers were used in varying proportlons of 0.5,
0.63 and 0.75 parts per part of base copolymer by weight and
on two different types of paper, bond paper and offset paper.
Each of these composltlons was then subiected to the Delrln
wheel test. The base adheslve copolymer alone had a Delrin
wheel value of 300mm. The results, ln mm travelled by the
Delrln wheel, are shown ln Table 3. As can be seen from the
table, addltlon of the tacklfler slgnlflcantly lmproved tack.
Table 3 Tackifier Evaluation - Wheel Tack
Paper Bond Offset
Tackifier 1:0.501:0.63 1 0.75 1 0.501:0.63 1 0.75
Bu diEtOH 16 15
Me diEtOH 50 45 34 16 20 16
diMe l-prOH 55 63 54 27 23 33
diEtOH 2-prOH 35 18
Examples 4-1 and 4-2
Two PSA composltions, a high tack compositlon and a
30 low tack composltlon, were formulated. The base copolymer ln
each case was the copolymer of Example 1-8 of Table 1, a
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copolymer of BA/SPE having a mole ratio of 80 20. The
zwitterionic tackifier A was Me diEtOH and B was Bu diEtOH.
The zwitterionic plasticlzer A was N-(2-hydroxy-3-
sulphopropyl)-N,N-dimethyl-N-~3-hydroxypropyl)-ammonlum
betaine. PVP K-30 and PVP K-90 were added to improve the
strength and toughness of the base copolymer of the
formulation. FC-171 (10%) was added to improve wetting of
the formulation. The quantities used are shown in Table 4 as
parts by weight based on 100 parts by weight of the base
copolymer.
Table 4 Formulations
Material Ex 4-1 High Tack Ex 4-2 Low Tack
(parts by weight)(parts by weight)
BA/SPE Copolymer 100 100
Zwitterionic Tackifier "A" 60
Zwitterionic Tackifier "B" 50
Zwitterionic Plasticizer "A" 10
20 PVP K-30 3.4
PVP K-90 3
FC-171 (10%) 0.067 0.092
These two formulations 4-1 and 4-2 were then tested
on five types of paper: AKD sized; offset; bond (European);
bond (Canadian); and rotogravure. Measurements were taken
for the following tests: shear strength; heat resistance; T-
peel; wheel tack (Delrln wheel); and repulpablllty (PST
test). In the column headed "repulpablllty" the entry "yes"
indlcates that the formulation was repulpable according to
the PTS test described above. The type of paper used is
shown in the left hand column under "paper" in Tables 5 and
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6. The results of the tests for formulatlon 4-1 (the hlgh
tack formulatlon) are shown in Table 5 and the results of the
tests for formulatlon 4-2 (the low tack formulatlon) are
shown ln Table 6.
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Table 5 "High Tack" Results (for formulation of Example 4-1)
Paper ShearHeat Resistance T-Peel Wheel Tack Repulp
Strength
,
(150~C 2kg)
min. sec. mm N/cm mm 10 min.
AKD Size 429.3 150 3.0 1.2 37 Yes
Offset 4400 2.0 25 Yes
Bond (Eur.) 461.7 150 0.0 1.6 49 Yes
Bond ~Can.) 253.1 150 0.0 1.5 54 Yes
10Rotogravure 4400 21 Yes
Ta~le 6 "Low Tack" Results ~for formulation of ExamPle 4-2)
Paper ShearHeat Resistance T-Peel Wheel Tack Repulp
Strength
(150~C 2kg)
min. sec. mm N/cm mm 10 min.
AKD Size 5600+ 130+ 0.1 0.59 Yes
Offset 6944+ 130+ 0.2 1.8 300+ Yes
20Bond (Eur.) 213.2 130+ 0.2 0.19 49 Yes
Bond (Can.) 3042+ 130+ 0.1 0.35 300+ Yes
Rotogravure 3042+ 130+ 0.4 1.1 241 Yes
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