TECHNICAL FIELD
[0001] The invention relates to a solid detergent composition comprising a carbonate builder
system.
BACKGROUND AND RELATED ART
[0002] Soaps, which are alkali metal salts of fatty acids, have traditionally been used
for the purpose of personal washing. Soaps have also been used for washing laundry.
When washing laundry with soaps, the efficiency of washing is lower when washed in
hard water. Hard water refers to water having high levels of dissolved Calcium and
Magnesium salts. The dissolved Calcium and Magnesium ions react very quickly with
the alkali metal cation (sodium or potassium) of the soap, leading to formation of
Calcium soap which is insoluble in water and therefore leading to poor detergency.
With the advent of synthetic detergents which are alkali metal salts of long chain
acids of petroleum origin, the same problem persists. Most popular synthetic detergents
include linear alkyl benzene sulphonates, alpha olefin sulphonates, and primary alkyl
sulphates which belong to the class of anionic surfactants. Surfactants of the non-ionic,
cationic, amphoteric and zwitterionic character are also known. Cleaning performance
of most synthetic surfactants is also affected by the washing in hard water.
[0003] Compounds that react preferentially with the dissolved Calcium and Magnesium ions
present in hard water, thereby maintaining the desired high concentration of the detergent
in its active form, have been used in detergent compositions. Such compounds or mixture
of compounds are known as detergency builders. Commonly known detergency builders
are alkali metal carbonates, silicates, phosphates and structured compounds like Zeolites.
Alkali metal carbonates like Sodium Carbonate, commonly referred to as soda is a very
inexpensive and widely used builder in low cost detergent formulations. Premium detergents
use builders like phosphates and/or Zeolites since they have better building properties
but are more expensive. There has been continuous work to develop more efficient and
faster building systems using less expensive materials. Further, use of phosphates
in detergents, is believed by many to be responsible for the eutrophication of rivers
and other natural waters bodies. Thus a lot of effort has been made to develop faster
building systems using soda as the main raw material.
[0004] EP0234818 (Unilever, 1987) discloses a detergent composition containing (i) a detergent active
system comprising a mixture of (a) an anionic non-soap detergent active; (b) a non-ionic
detergent active; and (c) soap; (ii) a watersoluble alkali metal carbonate; and (iii)
a water-insoluble particulate carbonate material which is a seed crystal for Calcium
carbonate; characterised in a specific combination of weight ratios of the various
detergent actives. The builder system in this publication is a mixture of soda and
calcium carbonate. There have been many improvements to this technology and many products
launched which are improvements over this basic technology where combination of soda
and Calcium carbonate is used. The present inventors have determined that the best
building systems available presently using sodium carbonate as the basic builder still
do not provide the desired fast building and there is scope for improvement on this
technology which can be perceived by the consumers in the cleanliness of their washed
laundry or in terms of costs of the products.
[0005] US7186677 (Henkel, 2007) describes a method for producing surfactant granules having good solubility
and varying bulk densities comprising (a) providing a mixture of anionic surfactant
acids and builder acids having a weight ratio of 1:100 to 1:20 of builder acid to
surfactant acid; and (b) contacting the mixture with at least one solid neutralising
agent. The builder acid is selected from citric, tartaric, succinic, malonic, adipic,
maleic, fumaric, oxalic, gluconic, nitrilotriacetic, aspartic, ethylenediaminetetracetic,
among many other acids wherein the builder acid has a particle size below 200 µm.
[0006] US 3,703,772 discloses a process for drying detergents wherein aqueous solutions of of heat sensitive
synthetic organic detergents are dried by admixing such a solution with a finely divided
sorbent material, thereby distributing the solution over a greatly increased area,
which speeds drying an prevents hot spots during drying and drying the mixed detergent-sorbent-moisture
particles.
[0007] US 2,717,243 discloses non caking alkyl sulphonate detergent compositions.
[0008] CA 979772 discloses detergent compositions for fabric washing.
[0009] Magnesium salt of linear alkyl benzene sulphonic acid is also known and has been
used in detergent formulations.
US4146551 (Lion, 1979) describes a process for producing the magnesium salt of sulphonic acids
and sulfuric esters comprising the step of neutralizing the sulphonic acids and sulphuric
esters with an aqueous dispersion containing (1) at least one neutralizing agent selected
from the group consisting of magnesium oxide and magnesium hydroxide and (2) at least
one neutralizing accelerator selected from the group consisting of benzoic acid, citric
acid, malic acid, phosphoric acid, polyphosphoric acid and water soluble salts thereof
under a pH of not more than approximately 6. Although this publication discloses use
of magnesium based anionic surfactants, it does not teach specific combination of
such surfactants with selected builder systems that provides enhanced building in
hard water and thereby enhanced detergency.
[0010] Indian patent
IN204326 (Hindustan Lever Ltd, published in 2003) describes a synergistic abrasive cleaning
composition containing selective combination of surfactants and a process for producing
the same. The process comprises neutralization of at least 40% of the acid precursor
of the anionic surfactant using at least one mineral of the dolomites group and mixing
abrasives and other conventional ingredients such that the total amount of surfactant
is between 0.5 and 35% and the amount of abrasives is 30-95% and processing the mixture
in a regular manner. Dolomite is a mineral having the chemical formula CaMg(CO
3)
2. This prior art publication is directed to hard surface cleaning compositions which
comprise Calcium-magnesium salts of anionic surfactants and does not teach combination
of magnesium salt of linear alkyl benzene sulphonic acid with selective builder systems
for providing enhanced detergency.
[0011] It is an object of the present invention to provide for a solid detergent composition
that provides for enhanced cleaning of soiled fabrics as compared to some of the prior
art compositions in hard water conditions.
[0012] It is another object of the present invention to provide for a solid detergent composition
that provides equal or better cleaning of soiled fabrics at lower cost compared to
some of the prior art compositions when cleaned in hard conditions.
SUMMARY OF THE INVENTION
[0013] According to the present invention there is provided a solid detergent composition
comprising
(i) 5 to 90 wt% of magnesium salt of linear alkyl benzene sulphonic acid;
(ii) 10 to 70 wt% of a water soluble alkali metal carbonate;
(iii) 3 to 50 wt% of a seed for precipitating calcium carbonate; and
(iv) an optional co-builder which is a di-carboxylic acid or a salt thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present inventors have found that use of the specific builder system disclosed
in
EP0234818 along with a specific co-builder provides for very fast building never before achieved
with similar systems.
[0015] Further the present inventors have determined that when a builder system comprising
a water soluble alkali metal carbonate and a seed for precipitating calcium carbonate
is used along with a specific anionic surfactant viz. magnesium salt of linear alkyl
benzene sulphonic acid, the building properties of this builder system combined with
the specific properties of this surfactant interact synergistically to provide enhanced
cleaning of soiled fabrics especially when washed in hard water.
[0016] The solid detergent composition of the invention comprises magnesium salt of linear
alkyl benzene sulphonic acid (Mg-LAS). The solid detergent composition is preferably
in the powder, granule, bar or tablet form. The more preferred form of the detergent
composition is the powder or granule form. When the detergent composition is present
in the powder or granule form, the Mg-LAS therein is preferably present as granules
in a particle size range larger than 0.3 mm, more preferably larger than 0.5 mm, most
preferably larger than 1 mm, and optimally in the range of 1 to 2 mm. The solid detergent
composition comprises Mg-LAS in an amount in the range of 5% to 90%, preferably 10%
to 50%, most preferably 15% to 35% by weight of the detergent composition.
[0017] A suitable process to prepare solid form of Mg-LAS is disclosed in our co-pending
application 445/MUM/2007 (published as
WO2008/107463). The process disclosed and claimed therein comprises the step of neutralization
of linear alkyl benzene sulphonic acids with a magnesium based alkali in the presence
of 3% to 28% water by weight of the reaction mixture in a high shear mixer. Mg-LAS
in very high concentration, as high as 90% in solid forms like powder, granule or
extrudable bar can be prepared by the above mentioned process. This process has the
advantage that only low amounts of alkali are required for complete neutralisation.
Preferred amounts for neutralization are from 5% to 100% stoichiometric excess of
the magnesium based alkali. Suitable magnesium based alkali are one or more of magnesium
carbonate, magnesium bicarbonate, magnesium oxide, magnesium hydroxycarbonate or magnesium
hydroxide.
[0018] A further preferred aspect of the detergent composition of the present invention
provides for the Mg-LAS granules to be coated with a water soluble polymer. The water
soluble polymers may be poly ethylene oxide, sodium carboxymethyl cellulose, poly
vinyl pyrrolidone, poly acrylic acid or poly vinyl alcohol most preferably poly vinyl
alcohol. The following processes can be adopted to coat granules of Mg-LAS with water
soluble polymers.
[0019] The preferred process for coating of Mg-LAS comprises the steps of spraying a solution
of polymer onto Mg-LAS in a pan granulator. The sprayed product may be dried by heating
the pan granulator to a high temperature, in the range of 60°C to 90°C to a moisture
content of the granules of less than 10 wt%. Alternately, the sprayed product may
be transferred to an oven to be dried. A fluidized bed may also be used for coating
the polymer with the use of hot air to dry the granules to the desired moisture content.
The preferred amount of polymer coating is from 0.25% to 5%, more preferably 0.5%
to 2% and most preferably 0.75% to 1.25% by weight of the Mg-LAS granules.
[0020] The solid detergent composition of the invention comprises a water soluble alkali
metal carbonate. The alkali metal is preferably sodium or potassium, sodium being
preferred. Thus the most preferred alkali metal carbonate is sodium carbonate. The
water soluble alkali metal carbonate is present in an amount in the range of 10% to
70%, preferably from 15% to 60%, most preferably from 25% to 50% by weight of the
solid detergent composition.
[0021] Another important element of the solid detergent composition of the invention is
a seed for precipitating calcium carbonate. By seed for precipitating calcium carbonate
is meant a compound which has the ability to act as a seed for precipitation of calcium
carbonate in aqueous media. The seed for precipitating calcium carbonate is a substantially
water insoluble particulate material. This water insoluble particulate material may
be present in the detergent composition or generated
in situ when the detergent composition is dispersed in water. The more preferred aspect provides
for the substantially water insoluble particulate material to be present in the detergent
composition. Examples of seed for precipitating calcium carbonate which is generated
in situ include generation of particulate zinc oxide by including sodium zincate in the detergent
composition, generation of particulate alumina by including sodium aluminate or generation
of silica by including alumino silicate in the detergent composition. Suitable substantially
water insoluble particulate materials which may be present in the detergent composition
are silica, zinc oxide, aluminium oxide, titanium oxide, Zeolite, magnesium oxide
or calcium carbonate. Particularly preferred substantially water insoluble particulate
material is calcium carbonate. Calcium carbonate may be calcite, or aragonite, most
preferably calcite. Calcite is preferably high surface area calcite. Preferably the
water insoluble particulate carbonate seed crystal has a surface area greater than
20 m
2/g; more preferably greater then 30 m
2/g, and most preferably greater than 60 m
2/g. The seed for precipitating calcium carbonate is present in an amount in the range
of 3% to 50%, more preferably from 5% to 40%, most preferably from 10% to 30% by weight
of the solid detergent composition.
[0022] The solid detergent composition optionally and preferably comprises a co-builder
which is a di-carboxylic acid or salt thereof. The co-builder present in the solid
detergent composition preferably has a water solubility of more than 1 g/l at 25°C.
Preferred di-carboxylic acids are oxalic acid, malonic acid and succinic acid, most
preferred being oxalic acid. The preferred salts of the di-carboxylic acid are alkali
metal or ammonium salts, alkal metal salts being more preferred. The most preferred
co-builder is di-sodium oxalate. The co-builder is preferably present in the solid
detergent composition as a powder i.e in a low particle size. The average particle
size of the co-builder is preferably less than 150 microns, more preferably less than
75 microns. The co-builder is preferably present in an amount in the range of 1% to
20%, more preferably 5% to 15%, most preferably 5% to 10% by weight of the solid detergent
composition.
[0023] The solid detergent composition of the invention preferably comprises an additional
builder that is alkali metal silicate. The alkali metal silicate is preferably sodium
silicate or potassium silicate, more preferably sodium silicate. Sodium Silicate is
a colorless compound of oxides of sodium and silica. It has a range of chemical formulae
varying in sodium oxide (Na
2O) and silicon dioxide or silica (SiO
2) contents. It is soluble in water and it is prepared by reacting silica (sand) and
sodium carbonate at a high temperature ranging from 1200°C to 1400°C. Aqueous solution
of sodium silicate is called water glass. Sodium silicates varying in ratio of Na
2O:SiO
2 from 1:1.6 to 1:4 are known as colloidal silicates. These are usually sold as 20%
to 50% aqueous solutions. Of the various types of sodium silicates available the preferred
compound to be used in the composition of the invention is neutral sodium silicate.
This has a concentration in water in the range of 27% - 39% and a Na
2O:SiO
2 ratio in the range of 3.0 to 3.5. The alkali metal silicate is preferably present
in 5% to 50%, more preferably 12% to 40% by weight of the solid detergent composition.
The use of the solid detergent composition in 2 g/l to 5 g/l of the wash liquor thereby
ensures presence of alkali metal silicate in 0.2 g/l to 1 g/l, preferably 0.5 g/l
to 0.8 g/l in the wash liquor.
[0024] According to another aspect of the present invention there is provided a process
to prepare a granular detergent composition comprising mixing granules of magnesium
salt of linear alkyl benzene sulphonic acid with powders of a water soluble alkali
metal carbonate, seed for precipitating calcium carbonate and a co-builder which is
a dicarboxylic acid or salt thereof.
[0025] According to a preferred aspect of the present invention there is provided a process
to prepare a detergent composition comprising the steps of:
(i) preparing granular form of magnesium salt of linear alkyl benzene sulphonic acid
(Mg-LAS) by neutralization of linear alkyl benzene sulphonic acids with a magnesium
based alkali in the presence of 3% to 28% water by weight of the reaction mixture
in a high shear mixer;
(ii) optionally sieving the granules of Mg-LAS to a size range greater than 0.3 mm;
and,
(iii) mixing said granules of Mg-LAS with powder of a water soluble alkali metal carbonate,
seed for precipitating calcium carbonate and co-builder, which is a dicarboxylic acid
or salt thereof.
[0026] It is preferred that the granules of Mg-LAS used in the above process are coated
with a water soluble polymer.
[0027] The invention will now be illustrated with respect to the following non-limiting
examples.
Examples
Examples 1 to 4 and Comparative Example A, B
[0028] These examples illustrate the building kinetics of detergent compositions of the
invention compared to conventional products - hand wash protocol.
[0029] Various detergent compositions as shown in Table -1 were prepared and added to hard
water of 48 FH (French hardness) using Protocol A as described below. All detergent
compositions had a surfactant concentration when in use of 0.7 g/l. The building kinetics
was studied by measuring the Ca
2+ concentration in terms of FH at various time points and the data is presented in
Table -2. The method of determining Ca
2+ concentration is given below:
Measurement of Calcium ion concentration
[0030] The method involved titration with EDTA (di sodium salt of Ethylene Diamine Tetra
Acetic acid) using EBT (Eriochrome Black - T) as indicator. About 2 ml of the Calcium
ion solution was pipetted out into a 150 ml conical flask. The solution was diluted
using 10 ml water. To this was added 5 ml of Ammonia-Ammonium chloride pH 10 buffer.
About 35 mg of 1% EBT in potassium nitrate solution was added. A wine red colour was
obtained. A standardized EDTA solution was added dropwise from a burette with constant
stirring. As more EDTA was added the colour gradually changed from wine red to violet.
The end point was identified by a sudden colour change from violet to blue. The calcium
ion concentration was calculated using the formula:
[0031] The Ca
2+ concentration in terms of FH was calculated using the formula:
Protocol A: Protocol used to simulate hand washing.
[0032] The 48 FH water was taken and the detergent composition was added to it and stirred
by hand for 45 seconds at about 70-80 rpm. After letting the solution stay for about
5 minutes, the solution was stirred vigorously for about 10 seconds. Samples were
then withdrawn at the desired time points using syringes and filtered using a syringe
filter into TARSON™ tubes. The filtrate was used to determine Ca
2+ ion concentration as described earlier.
Table-1
Example |
Surfactant |
Surfactant, particle size, mm |
Soda ash, g/l |
HSAC, g/l |
STPP, g/l |
Comparative Example A |
NaLAS |
0.5 - 1 |
1.4 |
0.3 |
0.16 |
Comparative Example B |
NaLAS |
0.5 -1 |
1.5 |
1.0 |
- |
Example 1 |
MgLAS |
1 - 2 |
1.5 |
1.0 |
- |
Example 2 |
MgLAS |
0.5 - 1 |
1.5 |
1.0 |
- |
Example 3 |
MgLAS |
1 - 2 PVA coated |
1.5 |
1.0 |
- |
Example 4 |
MgLAS |
0.3 to 0. 5 |
1.5 |
1.0 |
- |
NaLAS is sodium salt of linear alkyl benzene sulphonic acid HSAC: High Surface Area
Calcite with surface area of (20-30) m2/g.
STPP: Sodium tripolyphosphate
PVA: Poly Vinyl alcohol |
Table-2
Example |
FH, Time = 5 minutes |
FH, Time = 10 minutes |
FH, Time = 30 minutes |
Comparative Example A |
24.4 |
23.3 |
19.7 |
Comparative Example B |
19.1 |
10.5 |
8.2 |
Example 1 |
0.25 |
0.15 |
0.10 |
Example 2 |
0.30 |
0.18 |
0.15 |
Example 3 |
0.28 |
0.10 |
0.10 |
Example 4 |
4.50 |
6.80 |
6.80 |
[0033] The data in Table - 2 indicates that the detergent compositions of the invention
provide for much faster building kinetics as compared to a prior art products.
Examples 5 to 7 and Comparative Examples A, B
[0034] These examples relate to the building kinetics of detergent compositions of the invention
compared to conventional samples (Machine wash protocol).
[0035] Compositions of Comparative Example A and B and Example 5 to 7 as shown in Table
- 3 below were used to prepare wash liquor that simulates machine wash using a Protocol
B as described below:
Protocol B: (Protocol used to simulate washing machine)
[0036] The 48 FH water was taken and the detergent composition was added to it and stirred
by using an overhead stirrer at about 160-170 rpm. All detergent compositions had
a surfactant concentration when in use of 0.7 g/l. The stirring was continued for
a total time of 30 minutes. Samples were withdrawn at the desired time points using
syringes and filtered using syringe filter into TARSON™ tubes. The filtrate was used
to determine Ca
2+ concentration as described earlier.
Table-3
Example |
Surfactant |
Surfactant, particle size, mm |
Soda ash, g/l |
HSAC, g/l |
STPP, g/l |
Di-sodium oxalate, g/l |
Comparative Example A |
NaLAS |
0.5 - 1 |
1.4 |
0.3 |
0.16 |
- |
Comparative Example B |
NaLAS |
0.5 - 1 |
1.5 |
1.0 |
- |
- |
Example 5 |
MgLAS |
1 - 2 |
1.5 |
0.5 |
- |
0.4 |
Example 6 |
MgLAS |
0.5 - 1.0 |
1.5 |
0.5 |
- |
0.4 |
Example 7 |
MgLAS |
1 - 2; PVA coated |
1.5 |
0.5 |
- |
0.4 |
[0037] Di sodium oxalate was used in the above experiments in a particle size of < 0.075
mm.
[0038] The data on the building kinetics in terms of FH at various time points using Protocol
B for the compositions of Table - 3 is presented in Table -4 below.
Table-4
Example |
FH, Time = 5 minutes |
FH, Time = 10 minutes |
FH, Time = 30 minutes |
Comparative Example A |
20.0 |
21.0 |
20.0 |
Comparative Example B |
19.7 |
10.8 |
9.3 |
Example 5 |
4.69 |
0.10 |
0.10 |
Example 6 |
15.4 |
14.4 |
8.10 |
Example 7 |
0.30 |
0.30 |
0.30 |
[0039] The data in Table - 4 indicates that more preferred detergent compositions (Examples
5 and 7) of the invention provide for much faster building kinetics as compared to
prior art compositions.
Examples 8 to 12 and Comparative Examples A, B, C
[0040] These relate to the cleaning performance of detergent compositions of the invention
compared to conventional samples.
[0041] Compositions of Comparative Examples A to C and Example 8 to 12 as shown in Table
- 5 were used to wash various test monitors using a protocol that simulates hand washing.
This protocol C is described below.
Protocol C: (Hand wash protocol)
[0042] The 48 FH water was taken and the detergent composition was added to it and stirred
by hand at about 50-60 rpm for about 45 seconds. All detergent compositions had a
surfactant concentration when in use of 0.7 g/l. The solution was allowed to stand
for 5 minutes after which it was stirred by hand for 10 seconds. The fabric test monitors
were then added and allowed to soak for 10 minutes. The test monitors were then washed
in a tergo-to-meter at 90 rpm for 30 minutes. The test monitors were then rinsed three
times at a liquid to cloth ratio of 25 and then dried. The reflectance of the monitors
was then measured. Average of reflectance data on three different monitors was taken.
Table-5
Example |
Surfactant |
Surfactant, particle size, mm |
Soda ash, g/l |
HSAC, g/l |
STPP, g/l |
Comparative Example A |
NaLAS |
0.5 - 1 |
1.4 |
0.3 |
0.16 |
Comparative Example B |
NaLAS |
0.5 - 1 |
1.5 |
1.0 |
- |
Comparative Example C |
NaLAS |
0.5 - 1 |
0.89 |
0.07 |
1.02 |
Example 8 |
MgLAS |
1-2 |
1.5 |
1.0 |
- |
Example 9 |
MgLAS |
1-2 |
1.5 |
0.7 |
- |
Example 10 |
MgLAS |
0.5 - 1 |
1.5 |
0.7 |
- |
Example 11 |
MgLAS |
0.3 - 0.5 |
1.5 |
1.0 |
- |
Example 12 |
MgLAS |
0.3 - 0.5 |
1.5 |
0.7 |
- |
[0043] The data on the cleaning performance of various test monitors in terms of ΔR* with
respect to the reflectance of the original test monitors is shown in Table - 6. The
original (unwashed) test monitors used were WFK10D (composite soil on cotton fabric)
had an initial reflectance of about 45, WFK20D (composite soil on poly-cotton fabric)
of about 40 and WFK30D (composite soil on polyester fabric) of about 40.
Table-6
Example |
ΔR* WFK10D |
ΔR* WFK20D |
ΔR* WFK30D |
Comparative Example A |
20.0 |
18.5 |
17.6 |
Comparative Example B |
20.0 |
15.7 |
17.2 |
Comparative Example C |
22.2 |
22.9 |
20.5 |
Example 8 |
23.6 |
28.6 |
22.7 |
Example 9 |
21.3 |
26.1 |
21.1 |
Example 10 |
20.2 |
29.2 |
23.2 |
Example 11 |
17.8 |
22.4 |
20.3 |
Example 12 |
15.2 |
19.6 |
22.3 |
[0044] The data in Table - 6 indicates that the detergent compositions of the invention
provide for similar cleaning on some test monitors and better in most other test monitors
as compared to the prior art products. The data also indicates that Mg-LAS of higher
particle sizes (Examples 8 to 10) provides for vastly improved cleaning. Further the
cleaning of the preferred compositions of the invention (Examples 8 to 10) provide
for similar or better cleaning as compared to more expensive Na-LAS+STPP based conventional
products.
Examples 13 to 16 and Comparative Examples A and C
[0045] These examples relate to the cleaning performance of more preferred detergent compositions
of the invention compared to conventional products.
[0046] Compositions of Comparative Examples A and C and Examples 13 to 16 as shown in Table
- 7 were used to wash various test monitors using protocol C as described above.
Table-7
Example |
Surfactant |
Surfactant, particle size, mm |
Soda ash, g/l |
HSAC, g/l |
STPP, g/l |
Oxalic acid, g/l |
Comparative Example A |
NaLAS |
0.5 - 1 |
1.4 |
0.3 |
0.16 |
- |
Comparative Example C |
NaLAS |
0.5 -1 |
0.89 |
0.07 |
1.02 |
- |
Example 13 |
MgLAS |
0.3 - 0.12 |
1.5 |
0.5 |
- |
0.42 |
Example 14 |
MgLAS |
1 - 2 |
1.5 |
0.5 |
- |
0.42 |
Example 15 |
MgLAS |
0.5 - 0.3 |
1.5 |
0.5 |
- |
0.42 |
Example 16 |
MgLAS |
1- 2 |
1.5 |
0.5 |
- |
0.27 |
[0047] The particle size of the oxalic acid in the above experiments was in the size range
of <0.075 mm. The data on the cleaning performance of various test monitors in terms
of ΔR* with respect to the reflectance of the original test monitors is shown in Table
- 8.
Table-8
Example |
ΔR* WFK10D |
ΔR* WFK20D |
ΔR* WFK30D |
Comparative Example A |
20.0 |
18.5 |
17.6 |
Comparative Example C |
22.2 |
22.9 |
20.5 |
Example 13 |
22.4 |
22.3 |
24.2 |
Example 14 |
24.5 |
26.8 |
25.2 |
Example 15 |
24.0 |
26.8 |
23.3 |
Example 16 |
23.1 |
27.5 |
21.6 |
[0048] The data in Table - 8 indicates that preferred detergent compositions of the invention
provide for similar or better cleaning on some test monitors and much better cleaning
in most other test monitors as compared to the prior art samples. The data also indicates
that Mg-LAS at higher particle sizes > 0.5 mm when combined with co-builder like oxalic
acid provides for vastly improved cleaning.
Examples 17 and 18 and Comparative Example C
[0049] These examples relate to cleaning performance of more preferred detergent compositions
of the invention as compared to a conventional sample.
[0050] Compositions of Comparative Examples C and Example 17 and 18 as shown in Table -
9 were used to wash various test monitors using a protocol that simulates machine
washing. This protocol D is described below:
Protocol D: (Washing machine protocol)
[0051] The 48 FH water was taken in a Tergo-to-meter along with the test monitors and the
detergent composition was added to it and stirred for about 10 minutes at 90 rpm.
All detergent compositions had a surfactant concentration when in use of 0.7 g/l.
The fabric test monitors was then added and allowed to soak for 15 minutes. After
this it was run for 30 minutes at 90 rpm. The test monitors were then rinsed three
times at a liquid to cloth ratio of 25 and then dried. The reflectance of the monitors
was then measured. Average of reflectance data on three different monitors was taken.
[0052] The data on the cleaning performance of various test monitors in terms of ΔR* with
respect to the reflectance of the original test monitors is shown in Table - 10. The
original (unwashed) test monitors used were WFK10D (composite soil on cotton fabric)
had an initial reflectance of about 45, WFK20D (composite soil on poly-cotton fabric)
of about 40 and WFK30D (composite soil on polyester fabric) f about 40.
Table-9
Example |
Surfactant |
Surfactant particle size, mm |
Soda ash, g/l |
HSAC, g/l |
STPP, g/l |
Di-sodium oxalate g/l |
Comparative Example C |
NaLAS |
0.5 - 1 |
0.89 |
0.07 |
1.02 |
- |
Example 18 |
MgLAS |
1 - 2 PVA coated |
1.5 |
0.5 |
- |
0.40 |
Example 19 |
MgLAS |
1 - 2 PVA Coated |
1.5 |
0.5 |
- |
0.15 |
[0053] The particle size of the disodium oxalate in the above experiments was in the size
range of <0.075 mm.
[0054] The data on the cleaning performance of various test monitors in terms of ΔR* with
respect to the reflectance of the original test monitors is shown in Table - 10.
Table-10
Example |
ΔR* WFK10D |
ΔR* WFK20D |
ΔR* WFK30D |
Comparative Example C |
26.3 |
19.4 |
20.7 |
Example 17 |
26.5 |
26.5 |
24.2 |
Example 18 |
25.1 |
26.2 |
25.5 |
[0055] The data in Table - 10 indicates that preferred detergent compositions of the invention
provide for better cleaning on most test monitors as compared to the prior art compositions.
1. A solid detergent composition comprising:
(i) 5% to 90% by weight of the detergent composition of magnesium salt of linear alkyl
benzene sulphonic acid;
(ii) 10 to 70% by weight of the detergent composition of a water soluble alkali metal
carbonate; and
(iii)3 to 50% by weight of the detergent composition of a seed for precipitating calcium
carbonate and
(iv) optionally a co-builder which is a di-carboxylic acid or a salt thereof.
2. A solid detergent composition as claimed in claim 1 wherein water solubility of said
co-builder is more than 1 g/l at 25°C.
3. A solid detergent composition as claimed in claim 1 or claim 2 wherein said co-builder
has an average particle size less than 150 microns.
4. A solid detergent composition as claimed in any one of the preceding claims wherein
said co-builder is present in an amount in the range of 1% to 20 % by weight of the
detergent composition.
5. A solid detergent composition as claimed in any one of the preceding claims wherein
magnesium salt of linear alkyl benzene sulphonic acid is present as granules in a
particle size range larger than 0.3 mm.
6. A solid detergent composition as claimed in any one of the preceding claims wherein
the magnesium salt of linear alkyl benzene sulphonic acid is coated with a water soluble
polymer.
7. A solid detergent composition as claimed in any one of the preceding claims wherein
said seed for precipitating calcium carbonate is calcium carbonate with a surface
area larger than 20 m2/g.
8. A solid detergent composition as claimed in any one of the preceding claims comprising
an additional builder that is alkali metal silicate.
9. A process to prepare a solid granular detergent composition comprising mixing granules
of magnesium salt of linear alkyl benzene sulphonic acid with powders of a water soluble
alkali metal carbonate, a seed for precipitating calcium carbonate and a co-builder
which is a dicarboxylic acid or salt thereof.
10. A process as claimed in claim 9 comprising the steps of:
(i) preparing granular form of magnesium salt of linear alkyl benzene sulphonic acid
(Mg-LAS) by neutralization of linear alkyl benzene sulphonic acids with a magnesium
based alkali in the presence of 3 to 28% water by weight of the reaction mixture in
a high shear mixer;
(ii) optionally sieving the granules of Mg-LAS to a size range greater than 0.3 mm;
and
(iii) mixing said granules of Mg-LAS with powder of a water soluble alkali metal carbonate,
seed for precipitating calcium carbonate and co-builder, which is a dicarboxylic acid
or salt thereof.
1. Feste Waschmittelzusammensetzung, umfassend:
(i) 5 bis 90 Gewichts-%, bezogen auf die Waschmittelzusammensetzung, Magnesiumsalz
von lineares Alkyl-benzolsulfonsäure;
(ii) 10 bis 70 Gewichts-%, bezogen auf die Waschmittelzusammensetzung, eines wasserlöslichen
Alkalimetallcarbonats und
(iii) 3 bis 50 Gewichts-%, bezogen auf die Waschmittelzusammensetzung, eines Impfkristalls
zum Präzipitieren von Calciumcarbonat und
(iv) gegebenenfalls einen Co-Builder, der eine Dicarbonsäure oder ein Salz davon ist.
2. Feste Waschmittelzusammensetzung nach Anspruch 1, wobei die Wasserlöslichkeit des
Co-Builders mehr als 1 g/l bei 25 °C ist.
3. Feste Waschmittelzusammensetzung nach Anspruch 1 oder Anspruch 2, wobei der Co-Builder
eine durchschnittliche Partikelgröße von weniger als 150 Mikrometer hat.
4. Feste Waschmittelzusammensetzung nach einem der vorangehenden Ansprüche, wobei der
Co-Builder in einer Menge im Bereich von 1 bis 20 Gewichts-%, bezogen auf die Waschmittelzusammensetzung,
vorliegt.
5. Feste Waschmittelzusammensetzung nach einem der vorangehenden Ansprüche, wobei das
Magnesiumsalz von lineares Alkyl-benzolsulfonsäure als Körner in einem Partikelgrößenbereich
von größer als 0,3 mm vorliegt.
6. Feste Waschmittelzusammensetzung nach einem der vorangehenden Ansprüche, wobei das
Magnesiumsalz von lineares Alkyl-benzolsulfonsäure mit einem wasserlöslichen Polymer
überzogen ist.
7. Feste Waschmittelzusammensetzung nach einem der vorangehenden Ansprüche, wobei der
Impfkristall zum Präzipitieren von Calciumcarbonat ein Calciumcarbonat mit einer spezifischen
Oberfläche von größer als 20 m2/g ist.
8. Feste Waschmittelzusammensetzung nach einem der vorangehenden Ansprüche, die einen
zusätzlichen Builder umfasst, der Alkalimetallsilikat ist.
9. Verfahren zur Herstellung einer festen körnigen Waschmittelzusammensetzung, umfassend
Mischen von Körnern von Magnesiumsalz von lineares Alkyl-benzolsulfonsäure mit Pulvern
eines wasserlöslichen Alkalimetallcarbonats, einem Impfkristall zum Präzipitieren
von Calciumcarbonat und einem Co-Builder, welcher eine Dicarbonsäure oder ein Salz
davon ist.
10. Verfahren nach Anspruch 9, umfassend die Schritte:
(i) Herstellen einer körnigen Form von Magnesiumsalz von lineares Alkyl-benzolsulfonsäure
(Mg-LAS) durch Neutralisieren von lineares Alkyl-benzolsulfonsäure mit einem Magnesium-basierten
Alkali in Gegenwart von 3 bis 28 Gewichts-% Wasser, bezogen auf das Reaktionsgemisch,
in einem Hochschermischer;
(ii) gegebenenfalls Sieben der Körner von Mg-LAS zu einem Größenbereich, der größer
als 0,3 mm ist, und
(iii) Mischen der Körner von Mg-LAS mit Pulver eines wasserlöslichen Alkalimetallcarbonats,
Impfkristall zum Präzipitieren von Calciumcarbonat und Co-Builder, welcher eine Dicarbonsäure
oder Salz davon ist.
1. Composition détergente solide comprenant :
(i) 5 % à 90 % en poids de la composition détergente de sel de magnésium d'acide sulfonique
d'alkyl benzène linéaire ;
(ii) 10 à 70 % en poids de la composition détergente d'un carbonate de métal alcalin
hydrosoluble ; et
(iii) 3 à 50 % en poids de la composition détergente d'un germe pour précipiter le
carbonate de calcium et
(iv) en option, un co-adjuvant qui est un acide di-carboxylique ou un sel de celui-ci.
2. Composition détergente solide selon la revendication 1, dans laquelle l'hydrosolubilité
dudit co-adjuvant est supérieure à 1 g/l à 25 °C.
3. Composition détergente solide selon la revendication 1 ou la revendication 2, dans
laquelle ledit co-adjuvant a une taille de particule moyenne inférieure à 150 microns.
4. Composition détergente solide selon l'une quelconque des revendications précédentes,
dans laquelle ledit co-adjuvant est présent dans une quantité dans la plage de 1 %
à 20 % en poids de la composition détergente.
5. Composition détergente solide selon l'une quelconque des revendications précédentes,
dans laquelle le sel de magnésium d'acide sulfonique d'alkyl benzène linéaire est
présent sous forme de granulés dans une plage de tailles de particules supérieure
à 0,3 mm.
6. Composition détergente solide selon l'une quelconque des revendications précédentes,
dans laquelle le sel de magnésium d'acide sulfonique d'alkyl benzène linéaire est
revêtu avec un polymère hydrosoluble.
7. Composition détergente solide selon l'une quelconque des revendications précédentes,
dans laquelle ledit germe pour précipiter le carbonate de calcium est du carbonate
de calcium ayant une surface supérieure à 20 m2/g.
8. Composition détergente solide selon l'une quelconque des revendications précédentes,
comprenant un adjuvant supplémentaire qui est du silicate de métal alcalin.
9. Procédé de préparation d'une composition détergente en granulés solide consistant
à mélanger des granulés de sel de magnésium d'acide sulfonique d'alkyl benzène linéaire
avec des poudres d'un carbonate de métal alcalin hydrosoluble, un germe pour précipiter
le carbonate de calcium et un co-adjuvant qui est un acide dicarboxylique ou sel de
celui-ci.
10. Procédé selon la revendication 9, comprenant les étapes consistant à :
(i) préparer la forme granulaire du sel de magnésium de l'acide sulfonique d'alkyl
benzène linéaire (Mg-LAS) grâce à la neutralisation des acides sulfoniques d'alkyl
benzène linéaire avec un alcalin à base de magnésium en présence de 3 à 28 % d'eau
en poids du mélange réactionnel dans un mélangeur à cisaillement élevé ;
(ii) tamiser éventuellement les granulés de Mg-LAS au tamis à une plage de tailles
supérieures à 0,3 mm ; et
(iii) mélanger lesdits granulés de Mg-LAS avec la poudre de carbonate de métal alcalin
hydrosoluble, le germe pour précipiter le carbonate de calcium et le co-adjuvant,
qui est un acide dicarboxylique ou sel de celui-ci.