Improved Manufacture of Adhesive Pastes.
Year: 1895

page_text: Date of Application, 17th Sept., 1895-Accepted, 26th Oct., 1895
0
Improved Manufacture of Adhesive Pastes.
communication from CHARLES MICHAEL HIGGINS of 168 and 170 Eighth
Street, Brooklyn, County of Kings, State of New York, United States of
· America, Manufacturer..
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
scertained in and by the following statement:-
The main object of this invention is to provide an adhesive paste for mounting
photographs and other objects which obviates the, serious defects which exist with
the usual starch, flour, or tragacanth pastes. It is well known that in pastes made
of either pure starch and water, or of water and any of the cereal flours, such as
wheat, rye, rice etc., the starchy or glutinous matters do not exist in a state of perfect
solution or combination with the water, but only in a gelatinous or swelled state,
and after a limited time the water tends to separate from the adhesive matter
which is left in an inert gelatinous form which soon loses its homogeneity, and
rapidly deteriorates. Now as the water which thus separates always contains a
weak solution of extractive matter, and as such weak solutions are always very
subject to quick fermentation or putrefaction this will readily explain one cause
of the rapid change in such pastes, which as is well known, soon renders them
unfit for use. Now it is obvious that this offensive and destructive change would
not be nearly so likely to occur if the ingredients were to remain combined in
a dense solution for such changes do not take place readily in dense solutious,
but only in weak solutions as is well known to chemists and biologists. Another
great objection to the ordinary starchy and glutinous pastes is the large amount of
water required to hold or swell the gluten or starch to the desired consistency for
proper application, so that these pastes always contain a very great percentage of
water and a very small. percentage of solid adhesive matter swelled up into a great
or adhere
bulk by the preponderating water. Hence such pastes do not "catch"
very quickly and take a long time in drying and their moisture being so great and
not in tenacious combination with the adhesive matter strikes through the paper or
fabric being mounted, and hence tends to stain, warp and buckle the same in a very
objectionable manner, which has always been a serious objection to such pastes. In
the case of pastes made of gum tragacanth and water the conditions are almost
exactly the same as with starch or flour except that the union with the water, is
probably a little better and separation does not take place quite so readily.
Now the object of this invention is to provide an adhesive in a distinctly pasty
or non-fluid form, but of a soft and unctuous consistency which will contain more
solid adhesive matter and less water than the usual pastes, and in which the
adhesive matter will be in perfect combination or solution with the water, and not
liable to gelatinous separation, which will keep good indefinitely, be smooth and
easy of application, adhere quickly, and not strike through, stain or warp the
mount.
To these ends my correspondent has discovered that a paste having the desired
qualities can be produced from white dextrine and water when manipulated and
treated in the manner.hereinafter described which may be briefly stated to consist
in making a solution of white dextrine in hot water, then cooling the solution and

page_text: .
treating it to a long period of rest until matured into a non-fluid softly coherent
paste as hereinafter fully set forth.
Dextrines, of course, have been commonly used in pastes either wholly or in
combination, with other adhesive substances, but for such purposes the Fellow
dextrines have been generally used, and no paste such as now described has been
produced from white dextrine previous to this invention.
Where, however, dextrine has been used the pastes have been made too fluid
like mucilage, or too thick like a gummy mass, and not possessing that peculiar soft
coherent and unctuous consistency so much desired in a mounting paste, and which
the present invention secures. Indeed, the chief problem of this invention is to get
a dextrine solution in a non-fluid but soft pasty form with a less amount of dextrine
than usual so as to secure a smoother, lighter body, which will not spill, yet will
be taken up readily by the brush and spread more smoothly and easily, and yet
will not strike through the paper and will adhere quickly. Hence the gist of this
invention might be said to lie in imparting a certain physical condition or
consistency to the dextrine solution, as hereinafter shown.
The yellow dextrines are not amenable to the treatment or capable of producing
the result which is the gist of this invention, and which can only be obtained with
white dextrine which is a distinct variety.
In making the improved paste therefore white dextrine is taken and dissolved in
warm water, it being important that the solution be made in warm water, and at
a limited or moderate temperature, and also rapidly or in such manner as to avoid
any long continued heat, for it is found that if it is made at a high temperature or
under long continued heat the solution cannot be made to assume a proper pasty
form or have the soft unctuous non-fluid consistency, which distinguishes this new
product. Furthermore if the solution is made in cold water, it will remain
permanently fluid, and cannot be made to assume this non-fluid or pasty form unless
the solution is made so thick or dense as to be stiff and unyielding to the brusb,
incapable of easy spreading, too quickly drying, and useless for such reasons.
For an ordinary paste, take, say from four to six pounds of white dextrine to the
gallon of water, preferably about five pounds, six pounds being about the practicable
limit for proper consistency. The water should be heated only to about a scalding
temperature or preferably not over 160 or 170 F. usually from 150 to 160, although
a temperature down to nearly 100 can be used. As, however, a high temperature
.or long continued heat would prevent the solution from afterwards readily acquiring
the desired pasty consistency, it is found that a temperature of about 150 to 160 F
is usually preferable as the solution is effected so much quicker at this beat that it
avoids a longer continued heat which would be necessary to effect the solution at
a lower temperature, and which might even be more unfavourable to the desired
result than a bigher heat for a shorter time. A momentary high temperature
would not, however, be objectionable.
After the water has thus been raised to 150 or 160 the heat is shut off, and the
dextrine is at once added and dissolved as rapidly as possible by stirring, blending
or agitation, until a smooth clear solution is produced which will generally be
effected in about ten or fifteen minutes. Any desired untiseptics or flavouring
substances can be incorporated at the same time, so as to avoid any further stirring
or agitation after the solution is run off. The solution will now be a thin transparent
fluid whereas a starch or flour paste would become very thick at this moment of full
solution although it would contain much less solid matter and much more water than
this thin dextrine solution. The liquid dextrine solution will usually have a
temperature at this point of about 125 to 135, and it should now be allowed to cool
down as rapidly as possible to the temperature of the air, and should be at once filled
out into the jars, bottles, or other packages in which it is to be sold, so as to divide up
the hot mass as soon as possible and promote and quicken its cooling. The packages
should be then closed or sealed and laid away in a cool quiet place where they can
remain quiescent or at rest free from disturbance or agitation for a prolonged
period, usually from one week to one or two months 50 as to age or mature the

page_text: solution, which during this time, will entirely change its appearance and consistency.
When thus properly matured the solution in the jars will have acquired the following
qualities and appearance:That is, it will now be non-fluid and will not spill'or
flow, if the jar is inclined or inverted, and will have a pure opaque or porcelain
white colour sometimes opalescent instead of the transparent and thinly fluid form.
at the outset. Its consistency will now be such that while it is non-fluid and pasty
it will possess a very softly coherent or unctuous consistency, which enables it to
yield readily to the brush when dipped into the same and when blended or spread
with the brush it becomes smoothly fluid without any gelatinous granulation like
the usual pastes, which quality enables it to be spread in a most smooth and even
film over the mount. As the adhesive matter is 'in perfect solvent combination
with the water, of the solution, the water does not separate and soak into the paper
as is the case with flour and starch pastes, and as the solution tends to return to the
pasty or non-fluid form as soon as at rest from the movements of the brush, hence
the film spread on the mount does not strike through the paper but remains where
it has been placed by the brush, and will adhere at once and with great tenacity
when pressed to the surface on which the mount is to be fixed, thus effecting most
perfect mounting without any appreciable warping or cockling of the picture.
After this peculiar pasty consistency of the adhesive has been once acquired by
the treatment described it is permanent unless the paste is very much stirred or
agitated when it becomes fluid or rather fluent, but will return again to the soft
non-fluent form when again left at rest which is a most important quality.
By the treatment described this desirable consistency can be obtained with a
density of between four and five pounds of dextrine to the gallon of water or even
less, whereas without this treatment only a fluid form would be produced with that.
density, and to get the non-fluid form a density of six pounds or more would be
required, and then the paste would be so stiff or inert as not to yield to the brush.
when dipped into the same and would not be capable of being easily spread with
the brush, or when so spread would exist in a too thick and too quickly drying film
which would render good mounting difficult.
In order to expedite the maturing of the dextrine solution into the non-fluid but
soft unctuous pasty form described and to avoid the long period of rest specified,
my correspondent has discovered that the described condition can be produced in
a much shorter time by subjecting the liquid solution to a cold temperature which
greatly expedites the manufacture and also improves the product. To do this
the hot solution before being run out into the jars should be chilled or cooled down
rapidly by the application of cold furnished by crushed ice, a freezing mixture or
other source of cold so as to reduce it to a temperature about 40° or 50°, but a
higher or lower temperature will do, and the chilled solution is then filled at once
into the jars with as little stirring or agitation as possible and these jars are
sealed and then put into a refrigerated chamber to continue the chilling. The
temperature in this chamber should be kept about 40° or 50° F. preferably although
it may be lower or higher, but it should not be higher than 55°, which is about
the effective limit. The mixture will freeze at about 28° F. and although it will
not be appreciably injured by freezing, yet it is better to avoid this freezing
point as a limit in the lower direction and use a temperature of about 35° to
45° as the most efficient range. Where the jars or bottles are of small size the hot
solution can be filled directly into the same without previous chilling and can be
then put into the refrigerating chamber for chilling and maturing, but where the
packages are large, say eight ounces or over, the hot solution should first be chilled
or cooled before filling into the jars and then put into the refrigerator as it is
important to abstract the heat as rapidly as possible from all large masses, which
left to themselves would cool slowly by mere radiation.
"
By this chilling or refrigerating operation in addition to the period of rest the
adhesive may thus be matured into the non-fluid soft pasty form in a few days, or
in one week, more or less, and will then be ready for the market, thus making a
The quality will also be
great saving of time and space in the manufacture.

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improved as a firmer consistency, will be imparted without detracting from the
smoothness, homogeneity, and softness when spread with the brush. Another
advantage is that this consistency can be obtained with a much less density, that is,
with four pounds or less to the gallon, whereas from four and one-half to five
pounds would be required without the chilling operation to get a similar body,
while the adhesiveness of the lighter solution is not appreciably inferior to the
heavier solution, but is much preferable in not drying so quickly as the heavier
solution and thus giving more time for the proper manipulation of the mount which
is an important consideration in practical work. Furthermore the solution though
lighter has no more tendency to strike into the mount than the heavier solution on
account of the superior body imparted by the chilling which is of great importance.
It should be here understood that the superior consistency imparted by the
chilling is permanent,, and is not altered by afterwards keeping the paste in a
much higher temperature or within any habitable range say up to 100°, but
further heat up to near the point of solution would, of course, again liquefy
the adhesive.
For the purpose of this invention any good quality of white dextrine may be
used but preference should be given to potato dextrine rather than to that from
other forms of starch.
Having now particularly described and ascertained the nature. of this said
invention as communicated to me by my foreign correspondent, and in what
manner the same is to be performed, I declare that what I claim is :-
1. An adhesive paste formed of white dextrine and water substantially in the
manner and proportions described and having the qualities set forth; to wit:-
a white colour, homogeneous texture, and soft unctuous consistency being non-fluid
at rest, and becoming fluent on agitation, substantially as herein set forth.
2. The process of making an adhesive paste herein described, consisting in
dissolving white dextrine in warm water under conditions which avoid high or
continued heat, and then cooling this solution and treating it to a prolonged period
of rest until set or matured into a pure white pasty form, non-fluid at rest,
but becoming fluent on agitation, substantially as herein set forth.
3. The process herein described of making an adhesive paste, vis. : first dissolving
white dextrine in warm water forming a thin fluid solution and then cooling this
solution and keeping it refrigerated for a prolonged period until set or matured
into a non-fluid pasty form, substantially as herein set forth.
4. The herein described process of making an adhesive paste, viz.: first making
a thin liquid solution of dextrine in warm water, then filling said solution into
jars or packages and then cooling and keeping said packages at rest for a prolonged
period until the contents assume a white pasty form, substantially as herein set
forth.
5. The mode herein described of making an adhesive paste, viz. first dissolving
white dextrine in warm water at or about a scalding temperature, then cooling said
solution and keeping it refrigerated at or below a temperature of 55° until set or
matured into a white pasty form, substantially as herein set forth.
6. The novel process of making an adhesive paste consisting in first dissolving
white dextrine in warm water at or about a scalding temperature, then chilling
this solution, and then filling the chilled solution into jars or packages and keeping
said jars or packages refrigerated until the contents assume a white pasty form,
substantially as herein set forth.
BOULT & WADE,
Agents for the Applicant.