Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Inorganic silicon containing component
Reexamination Certificate
1999-07-01
2002-04-16
Gupta, Yogendra N. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Inorganic silicon containing component
C510S276000, C510S325000, C510S334000, C510S377000, C510S460000, C510S466000, C510S477000, C510S508000, C510S531000, C510S532000
Reexamination Certificate
active
06372709
ABSTRACT:
The invention relates to a finely divided crystalline layered sodium disilicate of the formula NaMSi
x
O
2x+1
.yH
2
O, where M is sodium or hydrogen, x is a number from 1.9 to 4, and y is a number from 0 to 20, to a process for its preparation and to its use.
Crystalline layered sodium silicates (phyllosilicates), in particular those of the formula NaMSi
x
O
2x+1
.yH
2
O, where M is sodium or hydrogen, x is a number from 1.9 to 4, and y is a number from 0 to 20, and preferred values for x are 2, 3 or 4, have proven to be suitable replacements for the builders phosphate and zeolite, especially in detergents and cleaners.
The use of the abovementioned crystalline phyllosilicates for softening water is described, for example, in EP-A-0 164 514. Preferred crystalline phyllosilicates are those in which M is sodium and x assumes the values 2 or 3.
Preferred replacements are either beta- or delta-sodium disilicates (Na
2
Si
2
O
5
.yH
2
O), it being possible to obtain beta-sodium disilicate, for example, by the process in PCT/WO 91/08171.
A commercially available crystalline sodium disilicate which corresponds to the abovementioned formula is, for example, SKS-6 from Clariant GmbH. This product is composed of the various polymorphous phases of sodium disilicate and thus consists of alpha-disodium disilicate, beta-disodium disilicate and delta-disodium disilicate. Preference is given to as high as possible a content of delta-disodium disilicate. The commercial product may also comprise components of noncrystallized sodium silicate.
The aim has hitherto always been to prepare sodium disilicates which comprise as high a content as possible of only one polymorphous phase, such as, for example with a delta-disodium silicate content of more than 90% by weight or above.
The sodium disilicates known hitherto can already satisfy a large number of the requirements placed on them. For example, they generally have high calcium-binding capacity and their other washing and performance properties are sufficient for many areas.
However, there continues to be a requirement for suitable substances which have very high calcium-binding capacity and at the same time produce only small dissolution residues in water (referred to below as sieve residue).
This object is achieved by a finely divided crystalline layered sodium disilicate of the type mentioned at the outset, which comprises
from 0 to 40% by weight of alpha-disodium disilicate
from 0 to 40% by weight of beta-disodium disilicate
from 40 to 100% by weight of delta-disodium disilicate
from 0 to 40% by weight of amorphous components.
The abovementioned alpha-disodium disilicate corresponds to the Na SKS-5 described in EP 0 164 514 B1, characterized by the X-ray diffraction data reproduced therein, which are assigned to the alpha-Na
2
Si
2
O
5
, whose X-ray diffraction patterns are registered with the Joint Committee of Powder Diffraction Standards under the numbers 18-1241, 22-1397, 22-1397A, 19-1233, 19-1234, 19-1237.
The abovementioned beta-disodium disilicate corresponds to the Na SKS-7 described in EP 0 164 514 B1, characterized by the X-ray diffraction data reproduced therein which are attributed to the beta-Na
2
Si
2
O
5
, whose X-ray diffraction patterns are registered with the Joint Committee of Powder Diffraction Standards under the numbers 24-1123, 29-1261.
The abovementioned delta-disodium disilicate corresponds to the Na SKS-6 described in EP 0 164 514 B1, characterized by the X-ray diffraction data reproduced therein which are attributed to the beta-Na
2
Si
2
O
5
, whose X-ray diffraction patterns are registered with the Joint Committee of Powder Diffraction Standards under the number 22-1396.
The finely divided crystalline layered sodium disilicate according to the present invention is notable for a binding capacity for water hardeners (calcium-binding capacity) which is greater compared with the prior art, and also for the fact that the dissolution residues in water (defined below by the sieve residue) are considerably reduced.
Preferably, the finely divided crystalline layered sodium disilicate comprises
from 0 to 20% by weight of alpha-disodium disilicate
from 0 to 30% by weight of beta-disodium disilicate
from 50 to 95% by weight of delta-disodium disilicate
from 0 to 20% by weight of amorphous components.
Particularly preferably, the finely divided crystalline layered sodium disilicate comprises
from 0 to 10% by weight of alpha-disodium disilicate
from 0 to 15% by weight of beta-disodium disilicate
from 70 to 90% by weight of delta-disodium disilicate
from 0 to 10% by weight of amorphous components.
The finely divided crystalline layered sodium disilicate is preferably free from sodium metasilicate or NS phases. It is also free from so-called NS phases, as defined, for example, in PCT/WO 97/19156 and in JP 7/327995 A1 and to which reference is here expressly made.
Preferably, the finely divided crystalline layered sodium disilicate has a d
90
value of <100 &mgr;m.
Preferably, the finely divided crystalline layered sodium disilicate has a d
90
value of <60 &mgr;m.
Preferably, the finely divided crystalline layered sodium disilicate has a calcium-binding capacity of more than 170 mg of CaCO
3
/g at 30° C. and 17° German hardness.
Particularly preferably, the finely divided crystalline layered sodium disilicate has a calcium-binding capacity of more than 180 mg of CaCO
3
/g at 30° C. and 17° German hardness.
In particular, the finely divided crystalline layered sodium disilicate has a calcium-binding capacity of more than 190 mg of CaCO
3
/g at 30° C. and 17° German hardness.
Preferably, the finely divided crystalline layered sodium disilicate has a sieve residue of less than 60%.
Preferably, the finely divided crystalline layered sodium disilicate has a sieve residue of less than 40%.
Preferably, the finely divided crystalline layered sodium disilicate has a sieve residue of less than 30%.
The invention also relates to a process for the preparation of finely divided crystalline layered sodium disilicates, which comprises grinding a sodium phyllosilicate having a particle diameter d
50
of from 80 to 400 &mgr;m to a d
90
value of <100 &mgr;m.
Preferably, the finely divided crystalline layered sodium disilicate is ground to a d
90
value of <60 &mgr;m in the above process.
Preferably, the process is carried out using a vibrating mill, ball mill, roller mill, pendulum roller mill or air-jet mill.
The invention also relates to the use of the finely divided crystalline layered sodium disilicates according to the invention for the preparation of detergents and cleaners, including dishwashing detergents.
The invention likewise relates to the use of the finely divided crystalline layered sodium disilicates according to the invention as builders.
The invention likewise relates to detergents and cleaners which comprise a finely divided crystalline layered sodium disilicate according to the invention, in particular in addition to other ingredients, active ingredients and auxiliaries. The amounts given below are, despite it not always being expressly mentioned, made up to a total of 100% by weight by customary ingredients, active ingredients and auxiliaries for detergents and cleaners.
Preferably, such detergents and cleaners comprise from 1 to 80% by weight of the finely divided crystalline layered sodium disilicate according to the invention.
Preferably, such detergents and cleaners comprise from 1 to 80% by weight of zeolite and from 1 to 80% by weight of the finely divided crystalline layered sodium disilicate according to the invention.
Preferably, such detergents and cleaners comprise from 1 to 80% by weight of zeolite, from 1 to 80% by weight of crystalline sodium phyllosilicate and from 1 to 80% by weight of the finely divided crystalline layered sodium disilicate according to the invention.
Preferably, such detergents and cleaners comprise from 1 to 80% by weight of the finely divided crystalline layered sodium disilicate according to the invention and from 1 to 10% by weight of citric acid or salts of citric a
Bauer Harald
Holz Josef
Schimmel Günther
Boyer Charles
Clariant GmbH
Gupta Yogendra N.
Hanf Scott E.
Jackson Susan S.
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