FORM 2
THE PATENT ACT 1970
(39 of 1970)
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rulel3)
1. Title of the invention:
"A PROCESS TO EASE THE TRANSPORTATION OF HIGH ACTIVE CONTENT SURFACTANT PASTES"
2. Applicant (s)
(a) Name: God rej Industries Limited
(b) Nationality: Indian company incorporated under the Indian Companies
Act, 1956
(c) Address: Pirojshanagar, Eastern Express Highway, Vikroli (East),
Mumbai - 400079, Maharashtra, India.
3. Preamble to the description
The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.

TECHNICAL FIELD OF THE INVENTION:
The present invention relates to a process to ease the bulk transportation of high active content surfactant pastes.
More particularly, the present invention relates to a process for reducing congealing temperature of high active surfactant paste by introducing a congealing temperature modifier at a temperature range of 60° - 80°C.
BACKGROUND AND PRIOR ART OF THE INVENTION:
Bulk transportation of high active content surfactant pastes (> 70% actives) requires the material to be maintained above its congealing temperature (greater than or equal to 60°C) all through its journey. This is necessary, because, once it congeals, the heat and energy required to make it flow-able again would be much more. This is a risky proposition since it is imperative that the temperature of the material does not overshoot 70°C. Beyond 70°C, certain types of anionic surfactants have a tendency to dissociate, resulting in a loss of active content. This limits the scope of operations to a very narrow range, from > 60°C to<70°C.
Therefore, in order to maintain the temperature of high active content surfactant pastes during bulk transportation, specially designed tankers are required. They are equipped with a sophisticated heating system, capable of continuously and consistently maintaining the temperature. Limited or irregular availability, the very high freight charges and a poor track record of reliability over long distances caused by these specially fitted tankers make the transportation of such pastes, having high active content, a time consuming, expensive and troublesome process, with no guarantee of success. Additionally, while transporting in smaller quantities, the material is packed into High Density Polyethylene (HDPE) barrels of various sizes. In the absence of any means to retain the temperature > 60°C the material in these barrels will congeal by the time they reach the customer. Therefore, the only means of easily and successfully transporting this material, such that the customer receives it intact and in its original form would be to lower its congealing temperature. This is the key to solve the transportation issues for both scales of the operation, bulk (tanker) and packed (barrels).

Multiple processes have been disclosed to reduce the viscosity of surfactant pastes at lower temperatures.US Patent US 4482470 discloses a process for the manufacture of powdery spray dried detergents by addition of polyglycol ether groups to the aqueous concentrates of anionic surfactants which results in to lowering the viscosity of the surfactant paste in the range 50 to 90°C. This invention was aimed at modifying the viscosity so that the material can be spray dried in the preparation of detergents. However the application does not discus the transportation related issues mentioned in above paragraph such as; maintaining the temperature by using thermally insulated containers having temperature maintained at > 60°C. However nothing was mentioned about the ease of transporting the resultant surfactant.
US Patent 4239641 also discloses the use of viscosity regulators for aqueous detergents compositions and not surfactant concentrates. The process was advantageous to overcome the process related problems during hot spray method of a formulated detergent preparation at elevated temperatures. According to the invention, the modifiers studied were simple alkanols (aliphatic alcohols) having 5 to 9 carbon atoms. There was no mention of poly-hydroxy alkanes or alkane diols and related compounds. Additionally, in terms of application, nothing was mentioned about ease of transportation.
US Patent 4532076 also described the addition of certain low molecular weight organic compounds, which when employed in concentrated detergent compositions provided improved rheological behaviour and could be handled without difficulty in processing there of, but did not cover either direct use in high active surfactant pastes or the aspect of transportation. Although, the process talked about addition of viscosity modifiers to the detergent slurry, there was no mention of the minimum temperature at which the resultant slurry could be flow-able or easily transferable from the holding vessel. Furthermore, surfactants contain about 30% by weight of a-sulfo fatty acid ester surfactants and are not highly concentrated.
In view of the technical dissimilarities and lacunae of the processes employed in the prior art, the inventors have devised the instant process which lowers the congealing temperature of high active surfactant pastes to ease the process of transportation. The temperature at which a substance passes from the liquid to the solid state upon cooling is

termed the congealing temperature. (Hong Wong, US pharmacoepiea USP-29-NF24). Lowering the congealing temperature results in facilitating the transportation of surfactant pastes. Considering the fact that this invention concerns itself with the easy transportability of high active surfactant pastes, which in the absence of this innovation, were very nearly impossible to successfully transport for long distances. This automatically increases the scope of useability. In addition, there is enhancement in the ease of loading and unloading operations of the paste from the containers.
The improvement in the ease of operations is due to the fact that by introducing the viscosity modifyng additive, the congealing temperature has been lowered to about 40°C, as against > 60°C without the additive.
SUMMARY OF THE INVENTION:
The present invention provides a process to ease the bulk transportation of high active content surfactant pastes.
In an aspect the invention provides a process for reducing congealing temperature of high active surfactant by introducing a congealing temperature modifier at a temperature range of 60°-80°C.
In another aspect the high active surfactant paste retains its active content even after reduction of the congealing temperature.
DETAILED DESCRIPTION OF THE INVENTION:
The invention will now be described in detail in connection with certain preferred and optional embodiments, so that various aspects thereof may be more fully understood and appreciated.
In a preferred embodiment the invention provides a process of reducing the congealing temperature to ease the transportation of high active surfactant pastes comprising:
a. Providing a high active surfactant paste having active content greater than 70%;
b. introducing 2.5% to 12.5% polyhydroxy alkanols to the surfactant paste of step a.
at 60°-80°C;

c. mixing the paste thoroughly to obtain a congealing temperature of about 40°C.
In accordance with the preferred embodiment, high active surfactant pastes having active content greater than 70% are subjected to treatment with polyhydroxy alkanols at 70°C. The surfactant pastes having high active content are selected from the group consisting of sodium lauryl ether sulfate (SLS), sodium alkyl sulfate, sodium a olefin sulfonate and sodium linear alkyl benzene sulfonate.
Treatment with polyhydroxy alkanols reduce the congealing temperature of the surfactant paste from >60°C to about 40oC thus rendering uniform mixing of the alkanols. The high active surfactant paste is easily flow-able and pump-able.
In an embodiment the invention provides congealing temperature modifiers selected from the group consisting of poly hydroxy alkanols consisting of alkane diols, alkane triols and polyethylene glycols.
In another embodiment the invention provides alkane diols selected from the group consisting of ethane- 1,2-diol, propane-l,2-diol and propylene glycol (PG), alkane triols are selected from the group consisting of glycerol, butane-l,2,4-triol, and hexane-2,3,5-triol and polyethylene glycols having molecular weight ranging from 400 - 1500.
In yet another embodiment, congealing temperature modifiers are added to high active surfactant pastes in concentrations ranging from 2.5% to 12.5% w/w%, more preferably 2.5 to 7.5 w/w % of additive, most preferably 5 w/w% of additive.
Accordingly, at concentrations of 2.5%, 5% and 10 % of alkane diols the congealing temperature of the surfactant paste blended with alkane diols is 53°C, 50°C and 42°C respectively.
Further, at concentrations of 2.5%, 5% and 10 % of alkane triols the congealing temperature of the surfactant paste blended with alkane triols is 48°C, 46°C and 44°C respectively.

At concentrations of 2.5%, 5% and 10 % of polyethylene glycol the congealing temperature of the surfactant paste blended with PEG's is 48°C, 40°C and 39°C respectively.
In a representative embodiment, the congealing temperature modifier polyethylene glycol 400 at concentration of 5 w/w % decreases the congealing temperature of the high active surfactant paste to 40°C.
In yet another embodiment the high active surfactant paste retains its active content even after reduction of the congealing temperature.
Accordingly, the decrease in congealing temperature of the paste does not compromise its active content. On addition of the congealing temperature modifier the active content of the surfactant paste is atleast 68%.
In another preferred embodiment the invention provides high active surfactant pastes comprising 2.5% to 12.5% of the congealing temperature modifier, thus reducing the congealing temperature of the paste to 40°C.
A further advantage of the invented process is that, with the additive, the window of operating temperatures for transportation has widened, from a very narrow range (> 60°C to < 70°C) to substantially wide (close to 40°C to < 70°C).
Industrial advantage:
Ease in transportation of high active surfactant paste will avoid the dependency on specially equipped transportation facilities and hence will alter the overall economy involved in the process of transportation and handling (loading and unloading operations), besides increasing its ability to be used in a wider variety of applications.
The invention will now be illustrated with help of experimental data and examples. The aforementioned embodiments and below mentioned examples are for illustrative purpose and are not meant to limit the scope of the invention. Various modifications of aforementioned embodiments and below mentioned examples are readily apparent to a

person skilled in the art. All such modifications may be construed to fall within the scope and limit of this invention as defined by the appended claims.
Experimental: Optimization Experiments:
A set of nine optimization experiments was carried out to determine the effectiveness of the three categories of congealing temperature modifiers at three different concentrations ranging from 2.5 - 10 w/w%. Each of the blending experiments was conducted on a scale of 200 gm of sodium lauryl sulphate (SLS) Paste.
Three modifiers selected were polyhydroxy alkanols including PG (representing alkane diols), Glycerin (representing alkane triols) and PEG 400 (representing the PEG's).
Each of them was mixed thoroughly at 70°C in concentrations of 2.5, 5.0 and 10 w/w%,
basis SLS Paste and congealing temperature was recorded with gradual cooling of the
mass.
Experiments were performed to comparatively determine the congealing temperature of SLS paste without addition of a modifier and respective blends of SLS and a polyhydroxy alkanols.
Table 1: Effect of the three categories of additives, at 3 preselected dosages, on congealing temperature

Experiment Nos. Blends 2.5% 5% 10%
1 SLS (Neat) 60°C
2, 5 and 8 SLS + PG 53°C 50°C 42°C
3, 6 and 9 SLS + Glycerin 48°C 46°C 44°C
4, 7 and 10 SLS + PEG 400 48°C 40°C 39°C
Table 1 shows that congealing temperature of neat SLS paste was 60°C. All the nine blended products were kept at 45°C to check the stability for 15 days and it was found consistent with respect to congealing temperature. Basis the above, the PEG category

proved to be the best performer, with respect to both, congealing temperature reduction and concentration.
After having selected the PEG's as the additives of choice, the next set of experiments were conducted, in order to establish which chain length was the best performer, and hence the most preferred. These experiments were conducted at a single concentration.
Table 2: Effect of various PEG's at a fixed dosage on the congealing temperatures

Experiment
Nos. Blends - Fixed Dosage (5%) of PEG Congealing temperature
10 SLS + PEG400 40°C
11 SLS + PEG 600 39°C
12 SLS +PEG 1500 42°C
Despite the results of Table 2, the most preferred additive is. PEG 400, being the most economical, as well. as being an acceptable additive in surfactant and detergent formulations.
The final set of experiments involves the most preferred dosage of the modifier additive.
PEG 400, which has already been selected as the most preferred additive, was used for
this set of experiments.
Table 3: Optimization of the amount of modifier required to lower the congealing
temperature

Experiment Nos. Dosage of PEG 400 Congealing Temperature
4 2.5" 48°C
7 5.0 40°C .
13 7.5 39°C
10 10.0 39°C
14 12.5 39°C

The above results indicate that beyond 5% there is a plateauing effect of the additive with respect to the congealing temperature. Therefore 5 w/w% of modifier amount was optimized with 40°C as congealing temperature.
EXAMPLE
70-75% active SLS (sodium lauryl Sulphate) paste was used for the study. Weighed quantity of SLS paste (200 gm) was heated to 70°C to make it in a fluid form for efficient mixing. Alkane Diols (1,2-propanediol (PG)), Alkane Triols [1,2,3-propanetriol (glycerin)] and PEG's (400, 600, and 1500) were used as congealing temperature modifiers and used based on weight % of SLS paste. Addition was carried out at 70°C with constant mixing and congealing temperature of the resultant material was recorded with gradually cooling it to 30°C over a period of 30 minutes.
It shall be understood that all aspects of the above invention are not limited to the specific depictions, configurations or proportions, set forth herein, which depend on various conditions and variables. Various modifications in form and detail of the invention will be apparent to a person skilled in the art. It is therefore contemplated that the invention shall also cover any such modifications, variations and equivalents.

WE CLAIM,
1. A process for reducing the congealing temperature of high active surfactant pastes
to ease the transportation thereof, comprising:
a. Providing a high active surfactant paste having active content greater than
70%;
b. Introducing 2.5% -12.5% polyhydroxy alkanols to the surfactant paste of step
a. at 60 - 80°C; and
c. Mixing the paste thoroughly to obtain a congealing temperature of about
40°C;
wherein the window of operating temperatures for transportation is widened from a narrow range of > 60°C to < 70°C to a substantially wide range of 40°C to < 70°C.
2. The process according to claim 1, wherein congealing temperature modifiers are selected from the group consisting of poly hydroxy alkanols consisting of alkane diols, alkane triols and polyethylene glycols.
3. The process according to claim 2, wherein alkane diols are selected from ethane-1,2-diol, propane-1,2-diol and propylene glycol (PG), alkane triols are selected from glycerol, butane- 1,2,4-triol and hexane-2,3,5-triol and polyethylene glycols (PEG) having molecular weight ranging from 400 to 1500.
4. The process according to claim 2, wherein congealing temperature modifiers are added to high active surfactant pastes in concentrations preferably 2.5 to 7.5 w/w % and more preferably 5 w/w%.
5. The process according to claim 2, wherein polyethylene glycol 400 at concentration of 5 w/w % decreases the congealing temperature of the high active surfactant paste to40°C.
6. The process according to claim 1, wherein the high active surfactant paste retains its active content after reduction of congealing temperature.

7. A high active surfactant paste with congealing temperature of less than 40°C comprising 2.5% to 12.5% of the congealing temperature modifier.