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Патент USA US2044467

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Patented June 15,. 1936
Theodore K. Cleveland, Drexel Hill, Pa., assignor
to Philadelphia‘ Quartz Company, Philadelphia,
Pa., a corporation oi.’ Pennsylvania
No Drawing. Application May 27, 1931,
Serial No. 540,497
sclaims. (Cl. 87-5)
' This invention relates to certain new preparations for cleansing operations as well as to a new
method of cleaning, and the principal objects as
well as the chief advantages of the invention will
5, be more clearly understood if the following brief
reference to the state of the art is ?rst presented.
It is at present recognized in the industries that
many of the customary commercial soluble silicates exert a distinct protective eifect in con10 trolling corrosion. This is particularly true of the
more silicious grades of the customary liquid silicates and the protection afforded is generally attributed to the formation of colloidal ?lms on the
surface to be protected, thus preventing access
15 0f the attacking agent. As examples where this
protective eifect has been utilized, there might be
mentioned the introduction of soluble silicates
into water heating systems or into iron or lead
municipal water distributing systems, etc. Small
20 amounts have also been added to shaving soaps.
- 001d Creams, 8150., which are marketed in metal
Furthermore, less silicious ‘silicates such as sodium metasilicate are characterized by a much
25 higher eii'ective alkalinity, as well as byvariations
in their ability to cause de?occulation, emulsi?cation, and the like.
In detergent practice, such factors astime, temDenture, Concentration, degree of agitation, etc”
30 all‘ have their eifect, and each industrial cleaning operation presents a complex of such factors
so that the choice of the detergent best suited to
the particular operation in hand, is a. matter of
some nicety.
- _
of different compositions which are dissolved and
used for cleaning purposes before their respective
constituents have come to a state of equilibrium.
This temporary state of non-equilibrium is char
acteristic of almost all systems in which two dif- 5 _
ferent soluble silicates are mixed although it is
obvious some combinations are more useful than
others. It has not heretofore been realized that
such combinations are useful because the art has
always assumed that a mixture of two or more 10
silicates would yield a solution having a set of
properties intermediate between the properties
of its components or that the different proper
ties of the respective silicates entering into the
mixture would unfavorably modify one another, 15
or, stated in other Words, would defeat the pur
pose for which the others were used.
Therefore, among the objects of my invention
may be cited the'following:
The provision of mixtures of alkali metal sili- 20
cates for cleansing purposes in which the prop
erties of the diiferent silicates. are employed si
multaneously in the same solution; the provision
of a detergent mixture of the character described
the action of which may be nicely regulated and 25
predetermined to suit the particular requirements
of the contemplated cleansing operation; the pro
vision of cleansing mixtures which ‘will have all
of the advantages of strongly alkaline constitu
ents while at the same time embodying the pro- 30
tective characteristics of the more silicious sili
cates; the provision of dry soluble mixtures of
alkali metal silicates of high RzOzSiOz ratio with
alkali metal silicates of low R2O:_Si0z ratio where
However, even with present knowledge on this
subject, it is often di?icult to arrive at a choice
which is altogether satisfactory. For example,
certain cleansing operat ons may require a sili-
R20 refers to the oxide of an alkali metal; and, 35
in general, the provision of detergent mixtures
of the alkali metal silicates which are adapted
for use in cleaning a wide variety'of surfaces and
cate of extremely active detergent characteristics,
40 and, therefore, one of high alkalinity. Such a
materials such as wood, paint, concrete, stone,
glass, metals, ?bers, textiles, and the like without
stancewto ‘be cleaned. At the same time a silicate of less active ‘characteristics may not yield
employing whatever degree of alkalinity may be
necessary or advantageous in obtaining the opti
the degree of cleansing which is most desirable.
‘mum degree of cleansing action, '
silicate may very well injure the article or sub- ' in any way injuring them while at the same time Hi
45 Under circumstances such as these, a compromisc ise-generally resorted to, a silicate of inter-
The foregoing, together with such other ob- 45
jects as may appear hereinafter or are incident
mediate composition or characteristicsv being
to my invention, may be obtained, by way of 11
lustration, according to the following example:
I have found, however, that it is possible to pre-
50 pare a cleansing solution in which is combined
the desirable features or characteristics of high
‘alkalinity and great detergent effect with the
‘protective characteristics so necessary in many
industrial cleaning operations. I obtain my im
55 proved results by preparing mixtures of silicates
Sodium metasilicate pentahydrate,
NdzSiOgJiHzO ............................................. _.
soluble Sodium silicate ha
10 lbs. 50
ving an analysis ap
I wish to point out also that although this in
vention has been developed around the use of
In the above formula, the NaaOiSlOa weight
percentage ratio for the metasilicate is 1:0.9'7;
- for the more silicious silicate, 1:322; and for the
sodium silicates, alkali metal silicates as a class
have been mentioned heretofore-and may serve
mixture of silicates, 111.88. The more silicious the purposes of the invention equally well al
silicates should be in the form of a ?ne powder though, of course, proper allowances are to be
free from lumps. The metasilicate may be used ' made for the individual differences of the specific
in the customary form available on the market, silicates to be employed.
most of which will pass the U. S. Bureau of
The combination of the more alkaline types
Standards 14 mesh screen or even coarser al . of soluble silicates with silicious materials not 0
soluble in water but yielding colloidal silica in
10 though I prefer to use it in ?ner form or to grind
the two silicates together during or after mix-l contact with alkaline solutions may produce
ring, thus preventing the tendency for the mix-_ washing solutions not in equilibrium, which are
tui‘e to separate into coarser and finer fractions.
The product is ready for use as a ?nely com
the full equivalent of the silicate mixtures here H Cl
tofore described. Sodium metasilicate and in
fusorial earthgtripoli, opaline or other hydrous
minuted dry mixture by whatever method pre
pared. This particular mixture is adapted to be
forms of silica will yield such solutions. 'They
put into solution in warm or hot water and used
at once, but it is obvious that similar results
may even be obtained from hydrous clays or
other insoluble silicates.
can be had by mixing the appropriate solutions
The invention contemplates
20 immediately before use. The example (is par
ticularly adapted to such type of service as re
further the use of ‘’ 3
added materials such as abrasives, caustics,
soaps,~saponin or other materials which may lend
moving oils, buf?ng or polishing compositions, additional desirable characteristics to the prod
milk products, etc., from soft metal surfaces such ucts of the invention either for general or specific
as lead, tin, copper, nickel, aluminum, zinc, etc.,'1
uses. Powdered rosin may be added in small
25 or alloys thereof, or from textiles, wood, etc.
As an example of a‘ mixture in which the action
of alkali is still further restrained, I cite the fol
Per cent
It should be pointed out that while I prefer
it is quite possible to prepare independent solu
. <
amounts, which will readily dissolve in the alka
line solutions to form a soap.
to prepare my improved mixtures in the form of
a dry powder, yet this, of course, is-not essential "
to obtaining the advantages of the invention as
yv Soluble sodium disilicate, of composition ap
tions and then bring them together or to add a
powder to an already prepared solution. In
short, the precisemanner in which the materials
are mixed is not important, although, as stated,
I prefer to provide dry 'mixtures containing the
Per cent
proper- proportions of the ingredients desired
N550 .......... “19.4
..10 lbs.
which can be made ready for use simply by dis 40
solving them in the proper quantity of water.
An intimate powdered mixture is'to be made
I also wish to‘ direct attention to the fact that
which may he put into solution in warm or pref
while in most instances the combination of two
erably hot- water and used immediately after dis
silicates will be suiilcient, yet, it is quite possible
to combine more than two should occasion de
; solving.
It is apparent that a series of mixtures each mand.
45 of which comprises basically an alkali metal sili
In conclusion, I should like to say that it is
well known that silicates which contain more
. cate of relatively low alkali oxide:
than two molecules of S102 for each R10 yield
.gether with a more alkaline alkali metal sili
cate, can be produced in which from one mix
solutions characterized by the presence of silica
ture to the next, the intensity of action may be ' in a colloidal state, and it is believed that this
regulated, either through change in alkali dxide is an important factor in detergent action. So
to silica ratio of one or both of the constituents, dium metasilicate and the more alkaline sili
orby alteration of the relative proportions of" cates, however, are crystalioidal in character but
constituents used in a given mixture. Such a have useful properties associated with their high
series of mixtures would be much more widely alkalinity. It has not heretofore'been known
55 adaptable to practical problems as they arise that these advantages could be combinedin one
solution. The range of composition of individual
than any single silicate.
It should be emphasized further that the components of .these mixtures may extend from
Soluble sodium silicate of composition approxi
property of protective action coupled with high
sodium hydroxide at one extreme to silica on
activity of alkali which such mixtures exhibit,
the other.
60 gradually diminishes after the mixture is put into -
As a consequence of the high proportion of silica
solution due to rearrangement between the'sili
and of buffering and colloidal action induced, the
cates. In time the properties of the mixture in more silicious silicates are less alkaline, that is to say, possess pH values lower than shown by meta
solution become those of a silicate of their ag
gregate composition and the intermediate . silicate or disilicate solutions of equivalent NazO
NazO1SiOz ratio. Such‘ a single silicate might ; concentration. It follows in general that the ac
have been separately prepared and put into so tion of a less silicious silicate on any object sub
lution directly but the advantages which are fea-, ject to attack of alkalis will be greater than that
tures of this invention would not be developed. of a silicate with a higher proportion of silica -T O
Heating speeds the rearrangement. The most when the NazO concentrations are'the same. The
differences in degree of this action are frequently
desirable combination of properties is to be ex
It is in many instances necessary never
pected ordinarily in freshly prepared solutions. great.
theless to use detergents dependent upon power
Old solutions cannot be expected to be as effec
ful alkaline action in cleaning or other operations 75
tive either in action or protection, even though eyen at the risk of some weakening of flber, etch
2,044,467 ‘
ing or other attack. It is to such operations that
_ the present invention is particularly directed in
that it provides a means of obtaining the highly
e?ective detergent or other action of the less sili
cious alkali metal silicates with the protective
action of those containing relatively more silica.
Such a combination of properties is inherent
in mixtures such as described. This is due to the
fact that although such mixtures possess ratios
intermediate between the ratios of the constituent
2. A detergent composition of matter compris
ing a physical mixture of a crystalline hydrated
sodium silicate and a second sodium silicate which
disperses in water to form a colloidal silicious sys
tem, the relative proportions of said silicates being .
such as to yield in aqueousrsolution a detergent
bath partaking of the individual characteristics
of the said silicates and adapted to be used before
equilibrium is attained.
‘3. A detergent composition of matter compris- l0
silicates, structural equilibrium between the two ‘
to give the properties of a single silicate of they ing av physical mixture of a crystalline hydrate
of sodium metasilicate and a second sodium sili
said intermediate composition when put into solu
tion is only slowly attained, each constituent sili cate which disperses in water to form a colloidal
cate exhibiting in considerable degree and for a
period of time the desirable properties for which
it was chosen as a component of the mixture.
Thus to cite a case, it becomes possible to clean
20 polished aluminum articles with such mixtures
and without etching, under conditions and with
satisfaction which would not be attainable were
either component used singly. The less alkaline
silicate would be found inefilcient in cleansing ac
25 tion; the more alkaline silicate too strong and
likely to ruin the ?nish. ,In the mixture the re
straining action exerted permits the use of higher
temperatures and correspondingly reduced pe-'
riods under treatment, or in other cases permits
30 the period in contact with solution to be increased
as dictated by convenience, for sterilization or for
other reasons.
What I claim is:—
1. As a new composition of matter, a dry mix-"
35 ture of sodium metasilicate pentahydrate and a
silicious system, the relative proportions of said
silicates‘ being such as to yield in aqueous solution 15
a detergent bath partaking of the individual char
acteristics of the said silicates and adapted to be
used before equilibrium is attained.
4. A detergent composition of matter compris
ing a physical mixture of crystalline sodium disili- 20
cate and a second sodium silicate which disperses
in water to form a colloidal silicious system, the
relative proportions of said silicates being such as
to yield in aqueous solution a detergent bath par
taking of the individual characteristics of the said 25
silicates and adapted to be used before equilibrium
is attained.
5. An aqueous cleansing solution comprising '
the composition of claim 1.
6. An aqueous cleansing solution comprising the 30
composition of claim 2.
7. An aqueous cleansing solution comprising the
composition of claim 3.
8. An aqueous cleansing solution comprising the r
second sodium silicate which it treated separately
with water disperses to form a colloidal silicious " composition of claim 4.
momma: x. cmvnmn'n.
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