Claims:We Claim:

1. A process for the preparation of freeflowing powders from aqueous polymers selected from the group consisting of 2-Propenoic acid, 2-methyl-,polymer with a-(2-methyl-1-oxo-2-propen-1-yl)-?-methoxypoly(oxy-1,2-ethanediyl), sodium salt and derivativesfollowing spray drying with a drying gas in a centrifugalatomizer, characterized in that the the aqueous polymer is preheated to a temperature of preferably 60oC before atomizing and injecting the aqueous polymer and precipitated silica in centrifugal atomizer and controlling the inlet and outlet temperature of the drying gas in the atomizer ensuring that the aqueous phase of the polymer does not melt at the selected inlet and outlet temperatures.

2. The process as claimed in claim 1, wherein the step of controlling the inlet and outlet temperature for obtaining polymeric powder from aqueous through centrifugal atomizer, is carried out maintaining the inlet temperature of the drying gas into the atomizer between 160 oC - 170 oC and the outlet temperature between 90 oC – 92 oC.

3. The process as claimed in claim 1 or claim 2, wherein the precipitated silicaused has water absorption is in the range of 300 % -350 % with particle size in the raneg of 5- 8 microns and Brunauer-Emmett-Teller (BET) surface area is minimum 180 m2/gm.

4. The process as claimed in any of the claims 1 to 3, wherein the purity of the precipitated silica used is maintained more than 98% on anhydrous basis.

5. The process as claimed in any of the claims 1 to 4, wherein the precipitated silica is used in the proportion of 10-12% of the amount of polymer.

6. The process as claimed in any of the claims 1 to 5, wherein the derivatives of the polymer from the group consisting of methacrylic acid, methoxypoly ethylene, glycol methacrylate copolymer sodium salt and sodium lauryl ether sulphate

7. The process as claimed in any of the claims 1 to 6, wherein the polymer has a glass transition temperature Tg of 43 °C to 44 °C.

8. The process as claimed in any of the claims 1 to 7, wherein the precipitaed silica used in selected amounts as an anticaking agent to reduce the stickeyness of the polymer powder and to get free flowing nature of the powder.

9. The process as claimed in any of the claims 1 to 8, wherein the particle size of free flowing powder obtained is less than 150 micron.

10. The process as claimed in anyone of claims 1 to 9 comprisingcarrying out the process maintaining dilution of liquid involving water /polymer % in the range of 42 to 43% preferably about 43% and with import air in drying chamber of 160-1700C.

Dated the 21st day of June, 2021
Anjan Sen
Of Anjan Sen & Associates
(Applicant’s Agent)
IN/PA-199
, Description:FORM 2
THE PATENT ACT 1970
(39 OF 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

1 TITLE OF THE INVENTION :
A PROCESS FOR PREPARATION OF DRY POWDER POLYMER.



2 APPLICANT (S)

Name : JSW CEMENT LIMITED.

Nationality : An Indian Company incorporated under the Companies Act, 1956.

Address : JSW CENTRE,
BANDRA KURLA COMPLEX,
BANDRA(EAST),
MUMBAI-400051,
MAHARASHTRA,INDIA.




3 PREAMBLE TO THE DESCRIPTION

COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates generally to a process for spray drying liquid polymers to obtain sustantially dry powder polymer particles by atomizing an aqueous solution of a polymer in a warm air stream and separating the polymer powder from the warm air stream which yields dry, free-flowing powders of polymer.

BACKGROUND OF THE INVENTION
The environment issues are becoming a problem with increasing greenhouse effect. The cement industry is responsible for the approximately 7% of the total CO2 emission. This emission from the cement manufacturing process can be reduced through reduction of clinker factor. The granulated blast furnace slag generated from the steel industry can provide the solution for the reduction of clinkering factor in the cement. However, to increase the consumption of GBS slag in cement making without affecting the performance of cement, polymeric materials can be used.

However, the polymer should be added in the powder form for uniform blending with cement.The liquid polymer in aqueous solution are not suitable for dosing either into clinker or in blending process in cement or in some other cementitious material. It’s hard to prepare powder because while making powder from liquid state most of the time the problems like lump formation, stickiness or even at high import temperature it does not transform into powder itself. There are few research works about preparing powder product. Therefore, this study used spray drying to prepare powder products of good performance and broaden vision application.
Efforts have been made for the production of polymer powder. Xiao Liu, Ziming Wang, Yunsheng Zheng, Suping Cui, Mingzhang Lan, Huiqun Li, Jie Zhu, and Xu Liang, 2014,“Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization”. 7(9): 6169–6183. In the study polycarboxylate superplasticizer (PCE) was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. However, the spray drying methods was not used for the synthesis of the polymer powder.
Miaomiao Gui, Yunhui Fang, Qingchang Lin, Feiyu Yu, Tianxing Lin and Xiuxing Ma, 2011. “The Preparation Research of Powder Polycarboxylate Superplasticizer”Applied Mechanics and Materials Vols 71-78, 677-683.In this research centrifugal spray drying process to prepare powder polycarboxylate superplasticizer. The spray drying process includes the speed of centrifugal atomizer is 16000r/min, feed liquid temperature is 30?, import / export air temperature of drying chamber is 200?/80?. It achieves a high concentration of polycarboxylate superplasticizer to prepare powder product. It solves the problem of sticky and low-performance of powder polycarboxylate superplasticizer during traditional preparation. However, this study is focused only on polycarboxylate material and its derivative.

In addition to mentioned studies, several referenced have also been made for the production of polymer powder. Patent WO2017214055A1discloses a method for preparing polymer. An embodiment of a method includes generating a resin solution including a first reaction solvent and a polymer resin dissolved therein; deploying the resin solution into a precipitation solvent contained in a chamber of a reaction vessel, wherein deploying the resin solution includes generating droplets of the resin solution; disturbing a resulting mixture of the resin solution and the precipitation solvent, wherein the mixture produces a precipitate; and generating a polymer powder from the mixture, including isolating the precipitate from a remaining portion of the mixture, and drying the isolated precipitate.However, the spray drying methods was not used for the synthesis of the polymer powder.

France patent FR2642079A1 discloses the process for the preparation of a polymer powder, comprising the steps of: separately mixing two or more oligomers and / or monomers which are reactive with each other, atomizing a mixture of the oligomers and / or monomers, while constantly mixing them with each other, the mixture being solid at room temperature and having a melt viscosity of 1 Pa or less, at 300 ?C , then cooling the atomized mixture, to obtain a powder consisting of the latter, and solid phase polymerization of this mixture, to obtain the polymer powder. However, the synthesis of polymer powder takes place at very high temperature of 300 ?C, which makes the process energy intensive.

German patent DE102013206267A1 relates to a process for preparing dispersion powders by spray-drying aqueous polymer dispersions of polymers of one or more ethylenically unsaturated monomers selected from the group consisting of vinyl esters, methacrylates, acrylates, olefins, dienes, vinylaromatics and vinyl halides with a drying gas in a nozzle atomizing dryer characterized in that the aqueous polymer dispersion (feed) is preheated under pressure to a temperature of 100 ° C to 200 ° C before being atomized and atomized at this temperature, wherein the pressure is adjusted so that the aqueous phase of the polymer dispersion in the selected Temperature does not boil. However, the inlet and outlet temperature in this study is 200 C and 98 C respectively, which is too high and may render the process. Also, the properties of anticaking agents used in the invention are not described.
Despite progress made by previous studies as shown in the above prior arts, further efforts are required for the coversion of liquid polymers with low glass transition temperature and low melting point to powder. The conversion of liquid polymer to powder form with centrifugal atomization is not present in related art.

OBJECTS OF THE INVENTION

The main object of the present invention is to provide a process for the spray-drying of aqueous polymer solution with which the limitaions and complexities of the drying process can be addressed without damaging the dried polymer powder.

SUMMARY OF THE INVENTION

The basic aspect of the instant invention is directed to a process for the preparation of freeflowing powders from aqueous polymers selected from the group consisting of 2-Propenoic acid, 2-methyl-,polymer with a-(2-methyl-1-oxo-2-propen-1-yl)-?-methoxypoly(oxy-1,2-ethanediyl), sodium salt and derivativesfollowing spray drying with a drying gas in a centrifugalatomizer, characterized in that the the aqueous polymer is preheated to a temperature of preferably 60 oC before atomizing and injecting the aqueous polymer and precipitated silica in centrifugal atomizer and, controlling the inlet and outlet temperature of the drying gas in the atomizer ensuring that the aqueous phase of the polymer does not melt at the selected inlet and outlet temperatures.

A further aspect of the present invention is directed to said process wherein the step of controlling the inlet and outlet temperature for obtaining polymeric powder from aqueous through centrifugal atomizer, is carried out maintaining the inlet temperature of the drying gas into the atomizer between 160 oC - 170 oC and the outlet temperature between 90 oC – 92 oC.

According to another aspect of said process, the precipitated silica has water absorption in the range of 300 % -350 % with particle size in the raneg of 5- 8 microns and Brunauer-Emmett-Teller (BET) surface area is minimum 180 m2/gm.

The precipitated silica has the purity of the precipitated silica is more than 98% on anhydrous basis.

The precipitated silica is used in the proportion of 10-12% of the amount of polymer.

According to a further aspect of said process of the present invention, the derivatives of the polymer selected from the group consisting of methacrylic acid, methoxypoly ethylene, glycol methacrylate copolymer sodium salt and sodium lauryl ether sulphate.

The polymer has a glass transition temperature Tg of 43 °C to 44 °C.

The precipitaed silica used as an anticaking agent to reduce the stickeyness of the polymer powder and to get free flowing nature of the powder.

In the above process, the particle size of free flowing powder obtained is less than 150 micron.

A further aspect of the present invention is directed to said process comprising carrying out the process maintaining dilution of liquid involving water/polymer % in the range of 42 to 43% preferably about 43% and with import air in drying chamber of 160-1700C.

The above and other objects and advantages of the present invention are described hereunder in details with reference to the following accompanying illustrative drawing and examples.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

FIG. 1 illustrates the flow chart of steps invoved in spray drying method of polymer powder manufacturing according to present invention.

Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity to help to improve understanding of embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO ACCOMPANYING DRAWINGS

The accompanying figure together with the detailed description below forms part of the specification and serves to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.

The present invention is now discussed in more detail referring to the drawings that accompany the present application. In the accompanying drawings, like and/or corresponding elements are referred to by like reference numbers.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts.

Before describing in detail embodiments that are in accordance with the invention, it should be observed that the embodiments reside primarily to the method of spray drying of polymeric material. More specifically, the present invention relates to the centrifugal automization spray drying of 2-Propenoic acid, 2-methyl-, polymer with a-(2-methyl-1-oxo-2-propen-1-yl)-?-methoxy poly(oxy-1,2-ethanediyl), sodium salt and its derivatives.

The present invention discloses a process 100 for the preparation of freeflowing powders by spray drying aqueous polymers with a drying gas in a centrifugal atomizeras illustrated in FIG.1. The process 100 comprises the following steps. In step 102, aqueous polymeric is batched with consistency of 50% and make up the aqueous solution of aqueouspolymer to 43% consistency.

The aqueous polymers selected from the group consisting of 2-Propenoic acid, 2-methyl-,polymer with a-(2-methyl-1-oxo-2-propen-1-yl)-?-methoxypoly(oxy-1,2-ethanediyl), sodium salt and derivatives. The derivatives of the polymer from the group consisting of methacrylic acid, methoxypoly ethylene, glycol methacrylate copolymer sodium salt and sodium lauryl ether sulphate. The polymer has a glass transition temperature Tg of 43 °C to 44 °C.

In step 104,the aqueous polymer is preheated to a temperature of 60oC before atomizing.

In step 106, the aqueous polymer and precipitated silica is injected in centrifugal atomizer. The inlet and outlet temperature of the drying gas in the atomizer is adjusted so that the aqueous phase of the polymer does not melt at the selected temperature.The inlet temperature of the drying gas into the atomizer is maintained between 160 oC - 170 oC and the outlet temperature is maintained between90 oC – 92 oC.The speed of atomizer is maintained to 13000 rpm while the maximum speed of atomizer is 15000 rpm.

The precipitaed silica used as an anticaking agent to reduce the stickeyness of the polymer powder and to get free flowing nature of the powder. The precipitated silica has water absorption is in the range of 300 % -350 % with particle size in the raneg of 5- 8 microns and Brunauer-Emmett-Teller (BET) surface area is minimum 180 m2/gm.The precipitated silica has the purity of the precipitated silica is more than 98% on anhydrous basis.The precipitated silica is used in the proportion of 10-12% of the amount of polymer..

The particle size of free flowing powder is less than 150 micron.

In step 108, the freeflowing powder is collected in collection chamber and cooled for 7-8 hours.

Lastly in step 110,the freeflowing powder is collected for final packing.

In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or composition that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article or composition. An element proceeded by "comprises...a" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or composition that comprises the element.

In the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless specifically stated otherwise.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Commonly used dictionary-defined terms are additionally interpreted as having meanings consistent with related technical documents and currently disclosed content and are not interpreted as ideal or very formal meanings unless defined.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

In addition, unless otherwise specified, % means weight%.

The advantages and features of the present invention and methods for achieving them will be clarified with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and are conventional in the art to which the present invention pertains. It is provided to fully inform the knowledgeable person of the scope of the invention, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

Thus, in some embodiments, well-known techniques are not specifically described to avoid obscuring the present invention. Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings commonly understood by those skilled in the art to which the present invention pertains.

The present invention is described further hereinafter by reference to a series of accompanying examples.

Experiments that were actually performed are now described by way of the following examples.

Examples
Example 1:
The polymer/ derivative of the liquid polymer charged with 50% concentration, the freeflowing nature of the obtained powder by spray dryinghas not been achived. Hence, material received remain lumpy, sticky and caky by nature. The sole reason behind the sticky nature and lumps formation in polymeric powder is access dilution.

Table 1: Powder manufacturing conditions
Parameteres Dilution of liquid polymer/derivative of polymer (water/reactive polymer %) Import air in drying chamber Charging % of precipitated silica
Condition 50 160-170 ?C 10-12

Example 2:
The import air temperature in drying chamber was maintained between 180-190 ?C. the freeflowing nature of the obtained powder by spray drying has not been achived. Due to low melting point and low glass transition temperature (tg) about 45 ?C of this material, it does not achieve the powder state at this import air temperature. Hence, material received was in liquid form. The sole reason behind the liquid nature of polymeric material is high termperature of import air in drying chamber.

Table 2: Powder manufacturing conditions
Parameteres Dilution of liquid polymer/derivative of polymer (water/reactive polymer %) Import air in drying chamber Charging % of precipitated silica
Condition 43 180-190 ?C 10-12

Example 3:
In case of precipitated silica charged upto 9-11% of the polymeric powder in drying chamber, the freeflowing powder after spray drying in atomizer could not achive and material received remain lumpy, sticky and caky by nature, so free flowing nature of the powder is not obtained. The sole reason behind this is availability of less ppt silica for powder formation.

Table 3: Powder manufacturing conditions
Parameteres Dilution of liquid polymer/derivative of polymer (water/reactive polymer %) Import air in drying chamber Charging % of precipitated silica
Condition 43 160-170 ?C 9-11

Example 4:
With the feed liquid consistency 43% at 60 ?C temperature, by using 10-12% ppt silica and import air temperature at 160-170 ?C, the freeflowing powder obtained.

Table 4: Powder manufacturing conditions
Parameteres Dilution of liquid polymer/derivative of polymer (water/reactive polymer %) Import air in drying chamber Charging % of precipitated silica
Condition 43 160-170 ?C 10-12

It is thus possible by way of the present invention to provideaprocess for the preparation of freeflowing powders by spray drying aqueous polymers selected from the group consisting of 2-Propenoic acid, 2-methyl-,polymer with a-(2-methyl-1-oxo-2-propen-1-yl)-?-methoxypoly(oxy-1,2-ethanediyl), sodium salt and derivatives with a drying gas in a centrifugal atomizer. The aqueous polymer is preheated to a temperature of 60oC to have 43% consistency before atomizing and injecting said aqueous polymer and precipitated silica used in the proportion of 10-12% of the amount of polymer, in centrifugal atomizer, wherein the inlet and outlet temperature of the drying gas in the atomizer is adjusted by maintaining the inlet temperature of the drying gas into the atomizer between 160 oC - 170 oC and the outlet temperature between 90 oC – 92 oC, so that the aqueous phase of the polymer does not melt at the selected temperature.