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Patented Dec. 31, 1946 I
CharlesiJifKrister, Wilmington, Del., and Henry
J. Sedusky and George‘ Li'Thompson; ‘Cleve
land,",‘0hio,-' assignors to ' E. I.‘ du‘ Pont de -
Nemours &‘Company, Wilmington, Dell., a cor
_ pora'tion of Delaware
No Drawing. Applicaticin'JunelSI 1943,
Serial N0. 491,394
f'zfcleinis. ., (01. 260-32)
through ‘a medium of a dried-down pe1yvmy1 al
cohol-reactive clay ?lm, and by the water-‘resist
This invention relates .to compositions com
prising polyvinyl alcohol and a clay cooperative
ant‘ structures so' produced.
therewith and to processes and articles employ
ing such compositions as'adhe'si'v'es, and is" more
- ' The processes and compositions of this inven
particularlydirected to adhesive and’ ?lml-fo'r'm- 5 ‘tion are applicable in any use where two or more
ing compositionscompri'sing polyvinyl alcohol
objectsare to be adhesively joined; The compo
and .a clay of the type of 'Chicora'No._3, to meth-
'sitions are particularly well-suited for use in‘ the
ads for producingwater-resistant joined strucjlam'inat'ed board industry, fOr instance, in- the
tures comprising aldhesively/unitin'g two’fo'r' more
manufacture of corrugated and solid ?breboard.
component parts with polyvinyl’ alcohollreactive 10 The compositionshave physical properties ideal
clay compositions, and to the, water-resistant
ly suited'for. use in modern corrugated board or
structures so producedf
solid fibreboard pasting machines, the adhesive
" ' .
_j. ~~ "
' It has alread'ybeen proposed ' to ' use solutions
of polyvinyl alcohol for v‘ various adhesivepur- ‘
setting up more rapidly than theadhesives here
tof'ore customarily used on such machines; The
poses. vI~Iovvever,for many‘purposes 'polyvinyl'al- 15 laminated ?breboard produced is unusually wa
cohol alone setsmuch' toojslowlyto be of_any"im_
ter-resistant, meeting all requirements of water
portant'co'mmercial‘value; Furthermorajthe ad"proofness for’such board.
hesive ?lms from a dried-down polyvinyi‘alcohol
' ,The polyvinyl alcohol usedin a composition‘ of
solution are so lacking injvwater vresistance that - ' ‘this invention suitably ‘may be prepared by hy
the suitability of structures jo'inedj‘with the‘poly- -zo"d'rolyrzing a, polyvinyl acetate solution and hence
vinyl alcohol adhesives,‘ is ‘severely restricted for
inayj contain some residual‘ polyvinylv acetate.
most purposes. variousimeth'o'ds have been proPrei'erably, the amount of suchpolyvinyl acetate
posed for improving the'waterre'sistance of such ' should be relatively low. The degree of polymer
acihesive films, but most'of thése‘niethod‘s require ‘ i‘za'tion of'the alcohol should be such as to give a
the use of agents which arefrelatively'expensive zsyis'ooéity in the solution‘ of from about 120'0-to
or heat treatments which complicate and’ ,in2200 centipoises measured at a concentration ‘of
Crease the cost oi the operation, Also,‘ the addi- '
'8 to 12%,‘ viscosities in the upper portion of this
tion agents ‘heretofore suggested tend‘ to' make 7 "range being particularly preferred-I
polyvinyl alcohol'adhesive solutions‘ un'stable and ' p ‘ The clay used in a composition of this inven
to alter their physical properties‘and make them 30 tiqn's'hould be one which'is cooperative with the
less desirable for use in such operations as the
"polyvinyl‘alcohol t0 givea‘water-insoluble Prod
manufacture of laminated ?breboard, where the
ilot'when an aqueous dispersion of the clay and,
physical properties of_the adhesive ‘are critical in
‘alcohol is" dried down- ,It is particularly pre
the operation of the commercial, pasting ma,- , ierredv to use a clay having" physical and chemical
chines used.
‘ '
f ,
" ,.
35 characteristicssubstantially identical with those
' It is an object of this invention to provide poly-
of a clay known as “Chicora No. 3,?’ which'is a
vinyl alcohol adhesive co'm'positionsjwhich-set up
rapidly after application 'as' adhesives: ,Another
South Carolina Cretaceous sedimentary kaolin
‘ having the following characteristics: . ‘
object is to provide‘ polyvinyl alcohol adhesives Y.
which dry down f1f0m_wa1;er dispersion
resistant adhesive ?lm's.
' '
water_. 40;
vAnotherobject .is to
‘ ' .Chemical analysis
provide water~resistant adhesives based on poly-
Particle size distribution
rf?‘gre‘lims 1
Per cent
Mimi‘ diameter Per cent
vinyl alcohol which give ‘water-resistant adhesive
?lms Without the useof expensive insolubiiizing
agents. Another objectfi's to provide water-re-
13-31 Above 10 microns;
33312 _
sistant structures‘ adhesively joined with adhe-
_ V
The foregoing and‘related objects of this, in
vention are accomplished by adhesive composi
tions comprising polyvinyl alcohol anda clay co
operative with the polyvinyl alcohol, particular
ly of the type of Chicoraj No. 3,.by processes for
producing water-resistant joined. structures in,
sives based on polyvinyl alcohol. Other objects
will appear hereinafter. _
lljvmssrilum vxidet________ _.
I‘Prcsont in ‘combined'forni, calculated as indicated.
7 To make an adhesive of-thisinvention one part
by weight of polyvinyl alcohol, on the dry basis,
is mixed with from about 1A? to 4 parts of clay.
which two or more components are united 55 For use in theimanufacture of corrugated board 1
or laminated ?breboard, it is preferred to use a
?breboard, the dispersion suitably may be applied
mixture of about 1 part of polyvinyl alcohol to
from 1 to 3 parts of clay, a mixture of 40% poly
vinyl alcohol and 60% clay being especially pre
ferred. It is preferred to supply the adhesive to
at the rate of about from 1 to 6 lbs. per thousand
square feet of glue line. Larger amounts may
be used under particular circumstances, but or
dinarily will not be found necessary or desirable.
Smaller amounts, while suitable under special
circumstances, are ordinarily inadequate to give
the trade in the form of a dry mixture of alcohol
and claysince the cost of transportation of. the
a bond of maximum strength.
dry adhesive is materially less, there is no problem
The finished adhesively—joined structures of
of stability of the mixture during storage, and an
adhesive solution may be made up by the user '10 this invention are characterized by their remark
in any concentration adapted to hisparticular
able resistance to water. A solid ?breboard made
needs. It is a unique characteristic of the dry
up of laminations joined with a polyvinyl alco
hol-clay adhesive of this invention will withstand
polyvinyl alcohol-clay mixtures of this invention
prolonged soaking in water without showing ply
that they are more readily dispersed in water than
are the separate components.
separation. As measured on astandard Mullen
testing machine, the wet bursting strength of
To make an adhesive solution from the dry mix
such board is remarkably higher than with board
ture of polyvinyl alcohol and clay, the mixture
7 made using polyvinyl alcohol alone'as the adhe
is cooked up with water to the desired concentra
tion. This may suitably be done, for instance, by
slurrying the solids in cold water and heating the 20
The invention will be better understood by ref
mixture to about 80° C. for 1/z to 1 hour. The
erence to the following illustrative examples:
adhesive may then be cooled approximately to
Example 1
'room temperature before use.
the application of an
The concentration of solids in the adhesive so
lution will depend in any particular instance on 25 adhesive of this invention to the preparation of
solid ?bre boxboard.
the use to which the adhesive is to be applied,
One hundred ‘pounds of a dry mixture of 40%
but, in general, the solids content preferably may
polyvinyl alcohol and 60% Chicora No. 3 clay was
be about from 10 to 25%. For use as a laminat
slurried with a mechanical mixer into 360 lbs. of
ing adhesive in making corrugated or solid fibre
board, a solids content of about 20% is preferred 30 cold water to form a homogeneous mixture. Live
steam was introduced and the temperature raised
and at this concentration it is especially pre
to 1'70—180° F. and maintained at that tempera- "
ferred to use a polyvinyl alcohol which with the
ture with stirring for 1/2 hour; About 40 lbs. of
clay used gives a viscosity in the range of about
steam condensed into the mixture to give a ?nal
from 1200 to 2200 centipoises in the liquid ad- hesive. A polyvinyl alcohol giving a viscosity near 35 mixture containing 20% solids.
After cooling to room temperature, this ad
the upper end of this range is particularly effec
hesive was used directly for the preparation of
four-ply solid ?bre boxboard on a commercial
The prepared adhesive solution of this invention
sealing machine. The paper used was highly
is a smooth, viscous liquid with considerable tack.
It is easy to handle and exhibits a remarkable .40 alum-rosin sized Kraft, 0.024—0.026" thick, 92-424
degree of stability. The material shows no de
terioration over considerable periods of time. . As
‘ lbs. per thousand square feet, 64” wide.
Excellent board was made from the start of
the machine. There was no separation of the
‘used on modern pasting machines the mixture
ply and‘ immediate bonding was evident. The
shows a high tack without excessive stringiness
or “webbing” effects. In this respect, the mix 4.5 machine was operating at a speed of 170-200 feet
per minute and the adhesive was applied at the
ture of clay and polyvinyl alcohol is superior to
rate of approximately 4-6 lbs. per thousand
the polyvinyl alcohol alone.
square feet of glue line.
In using a polyvinyl alcohol-reactive cla
The prepared board was highly water-resistant.
water dispersion as an adhesive according to this
invention, the a'queousdispersion is applied as a 50 There was no ply separation upon immersion in
Water after a period of several months.
film to one of the surfaces to be united and the
second surface is superimposed on the ?lm and
Eaiample 2
held‘in place while water is removed. The man
illustrates the applica
ner of removing water may be , any method
tion of an adhesive of this invention to the pro
adapted to the particular situation. For instance,
duction of corrugated board.
in laminated paper-board'water is instantaneously ,
A dry mixture of 30% polyvinyl alcohol and
removed by diifusion into the paperboard mem
70% Chicora No. 3 clay is used after cooking in
bers which are being joined, followed by evapora
water at a solids content of about 25%.
tion therefrom, the adhesive setting immediately.'
In preparing the liquid adhesive 100 lbs. of dry
It will be understood that various methods may
adhesive is slurried with 370 lbs. of cold water
be used to augment the rate of water removal,
such as applying heat or suspending unswelled
by means of a, mechanical stirrer. When a homo
starch in the polyvinyl alcohol-clay dispersion, the
geneous mixture is obtained, live steam is intro
duced to raise the temperature to I'M-180° F.
This temperature is ‘maintained for 1/2 hour with
unswelled starch taking up a considerable amount
of water upon the application of heat in the paper
pasting machine.
_ stirring and the adhesive cooled for use. The live _
Agents designed to promote the setting up of - ' steam will condense sui?cient water into the mix
ture to bring the'solids content to approximately
the polyvinyl alcohol-clay mixture may. be ap
plied to the surfaces to be joined. For instance,
The adhesive is found to have a satisfactory
when using the adhesive in laminated ?breboard.
the laminations may be highly sized with rosin 70 setting time for operation upon a corrugated
alum size or with any other polyvinyl alcohol
board machine. The adhesive is waterproof, as
insolubilizing agents, of which dimethylol "urea
evident from the fact that double face board
and trimethylol melamine are representative.
In using an aqueous polyvinylalcohol-clay dis
shows no ply separation upon immersion in water
after a period of over a month. The adhesive
persion of this invention for producing laminated 75 prepares particularly satisfactory board when
4. A dry composition adapted to be dispersed
used with water-resistant.’ highly alum-rosin
sized paper.
in water, comprising 40% by weight, on the dry
Under those conditions the corru
basis, of polyvinyl alcohol and 60% by weight of
gated board shows considerable strength vat the
a clay substantially identical with Chicora No. 3,
the mixture having a viscosity, when dispersed
glue line after immersion in water for several
in Water to give a 20% solids content, of about
While in theforegoing description of this in—
vention certain speci?c embodiments have been
shown, it will be understood that without depart
from 1200 to 2200 centipoises.v
ing from the scope of the invention'those skilled '
in the art may produce various adhesive compo
sitions and adhesively ‘joined structures and may
employ various processes using such adhesives.
We claim:
5. An adhesive. and ?lm-forming composition,
comprising an aqueous solution of polyvinyl alco
hol, the solution containing a clay substantially
identical with Chicora No. 3 in an amount 1%
‘times the dry weight of polyvinyl alcohol, the
total solids content, dueto polyvinyl alcohol and
1. A dry composition adapted to be dispersed ‘ q.,clay, being about 20%, andthe clay-containing
in water, comprising one part by weight of poly 1.5 solution having a viscosity of about from 1200 to
vinyl alcohol on the dry basis‘ and from V2 to _4
parts of a clay substantially identical with’
Chicora No. 3.
2200 centipoises.
6. A dry composition adapted'to be dispersed
in water, comprising one part by weight, on the
2._An adhesive and ?lm-forming composition,‘ vdry basis, of polyvinyl alcohol and from 1/2 to 4
comprising an'aqueous solution of polyvinyl alco 20 parts of a kaolinite-type clay, the mixture hav
ing a viscosity of about from 1200 to 2200 centi
hol containing a clay substantially identical with
poises when dispersed in water to give a 20%
Chicora No. 3, the clay being present in an
solids content.
amount from 1/2 to 4 times the weight of the poly
'7. An adhesive and ?lm-forming composition,
vinyl alcohol and the total solids content, due to
clay and polyvinyl alcohol, being about from 5 25, comprising an aqueous solution of polyvinyl alco
to 25%.
3. A dry composition adapted to be dispersed
hol containing a kaolinite-‘type clay, the, clay be
ing present in an amount from V2 to 4 times the
weight of the polyvinyl alcohol and the total
in water, comprising one part by weight, on the
solids content, due to clay and polyvinyl alcohol,
dry basis, of polyvinyl alcohol and from 1/2 to 4
parts of a clay substantially identical with 30 being about from 5 to 25%.
' Chicora N0. 3, the mixture having a viscosity,
when dispersed in water to give a 20% solids con
tent, of about from 1200 to 2200 centipoises.
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