FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
PROVISIONAL / COMPLETE SPECIFICATION (See section 10 and rule 13)

1. TITLE OF THE INVENTION
Copolymeric/Terpolymeric inhibitors for scale control in aqueous systems.
2. APPLICANT PH AQUA ARM CHEMICALS PVT.LTD
3. (a) NAME
. (b) NATIONALITY An Indian Company registered under
the Provisions of
The Companies Act, 1956
(c) ADDRESS S-l, M.I.D.C, Bhosari,
Pune-411026,
• India.
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL COMPLETE
The following specification describes the The following specification^,—-"
invention. particularly describes-rrlemvention and the manner in which it is to be performed.
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Title: Copolymeric/Terpolymeric inhibitors for scale control in aqueous systems.
Technical field:
The invention relates to copolymeric/terpolymeric inhibitors for scale control in aqueous systems comprising atleast one copolymer or terpolymer comprising following monomers in polymerized form: I. Less than 50% by weight of one or more weak acids II. 0-50 % by weight of one or more strong acid III. 10-70 % by weight of one or more monoethylenically unsaturated
monomers polymerizable with I & II wherein the total of monomers I, II and III equals 100 % by weight of copolymer/terpolymer.
Prior art:
Many industrial applications and residential areas utilize water containing relatively high concentration of inorganic salts. Such salts are formed due to metal cations such as calcium, magnesium, barium with inorganic anions such as carbonate, phosphate, sulphate and silicates. Since these salts have low solubilites in water, they tend to precipitate from solution, crystallize and form hard deposits on the surfaces when their concentration increases or temperature or pH of water containing them increases. Scale formation is a problem in heat transfer devices, boilers, secondary oil recovery and on clothes washed with such hard waters.
Control of scales containing scale-forming salts in aqueous system involves one or a combination of mechanisms. Such scale control can take place by anti precipitation, dispersion of precipitated salt crystals. The adsorption of the inhibitor can also be used to stabilize the aqueous system. Another mechanism is
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the ability of inhibitor to interfere with and distort the crystal structure of the scale making the scale more easily fracturable and dispersible.
Polymers derived from (meth)acrylic acids and salts as well as mixtures of such polymers with other compounds and polymers, such as phosphonic acids, have long been used as precipitation inhibitors for aqueous systems. Copolymers of (meth)acrylic acids and vinyl esters, such as hydroxy ethyl methacrylate and hydroxy propyl acrylate, and copolymers of (meth)acrylic acids and salts with acrylamido alkyl or aryl sulphonates or unsubstituted acrylamides have also been used for water treatment.
US 4711725 disclose a water-soluble terpolymer and interpolymer which when added to aqueous system exhibits improved phosphate stabilization and iron and zinc stabilization. This prior art particularly teaches stabilizing aqueous system containing calcium phosphate scale with or without presence of iron.
US 5277823 discloses a method for controlling silica or silicate scale formation in aqueous system.
US 6114294 discloses the inhibition of tripolyphosphate and pyrophosphate scales in aqueous systems. This patent also discloses detergent formulations, which have good anti-filming performance characteristics when used in machine dish washing and good anti-encrustation and anti-deposition performance characteristics when used in laundry washing detergents.
US 2006/0191852 Al discloses a polymer; capable of inhibiting CaC03 & Phosphate scale inhibition.
Despite the large number of publications in this area disclosing scale inhibition, dispersion, and/or stabilization of aqueous systems utilizing polymers derived from (meth)acrylic acid, AMPS and ethylenically unsaturated monomers,
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not one conventional material or combination is found to be effective as phosphate inhibitor as well as silica/silicate inhibitor and also as an encrustation inhibitor.
As used herein the term copolymer defines a polymer formed from two monomers and the term terpolymer defines a polymer formed from three monomers.
Object of the invention:
1. It is an object of the present invention to provide copolymeric and/ or terpolymeric inhibitors, which provide phosphate stabilization in aqueous system.
2. It is also an object of the present invention to provide selected copolymeric and/ or terpolymeric for the stabilization of silica/silicate scales in aqueous system.
3. It is a further object of the invention to provide certain copolymeric and/ or terpolymeric inhibitors which function as encrustation inhibitors when used in laundry washing detergent.
Detailed description:
The present invention discloses copolymeric or terpolymeric inhibitors for scale control on aqueous systems. The copolymeric or terpolymeric inhibitors acoording to the present invention are effective in controlling phosphste and/or silica or silicate scale formation in aqueous system. Further, the copolymeric or terpolymeric inhibitors according to present invention posses anti-filming characteristics when
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used in dish washing detergent formulations provides detergent formulations and good anti-encrustation characteristics when used in laundry detergents.
According to the present invention the copolymeric/terpolymeric inhibitors for scale control in aqueous systems comprise atleast one copolymer/terpolymer comprising following monomers in polymerized form:
IV. Less than 50% by weight of one or more weak acids V. 0-50 % by weight of one or more strong acid VI. 10-70 % by weight of one or more monoethylenically unsaturated monomers polymerizable with I & II wherein the total of monomers I, II and III equals 100 % by weight of copolymer/terpolymer.
In the copolymeric or terpolymeric inhibitors of the present invention, the weak acid is selected from (meth)acrylic acid or salt. The strong acid is acrylamido alkyl or aryl sulphonate or salt. Monoethylenically unsaturated monomer is a new monomer alkanolamido carboxylic acid of following formula: R

wherein R8 is H or – COOM1, Mi is H or metal cation, R is H or CH3, R4 is H or C1_C12 alkanol or alkyl and R5 is Ci - Cl2 alkyl.
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According to the present invention, the ratio of atleast one and/or two selected monomers and third new monomer is selected in order to provide scale inhibition and encrustation inhibition thus providing multiple performance characteristics.
The copolymers/terpolymers of the present invention contain units derived from three ionic types of monomers
1. (meth)acrylic acid or salt
2. acrylamido alkyl or aryl sulphonates
3. alkanolamido carboxylic acid or salt
The weight percent of the units of the copolymers or terpolymers, which are derived from (meth)acrylic acids and salts there of can be less than 50 % and preferably 25 to 45 %. These (meth)acrylic acids and salts have the following structural formula
Rl C C R3
R2 COOMj
Wherein Rj, R2&R3 are independently selected from hydrogen, methyl and Ml is independently hydrogen, monovalent metal, ammonium group or organic amine group.
According to the present invention, the (meth)acrylic acids and salts may include acrylic acid, methacrylic acid and sodium salt component of the selected copolymers or terpolymers for use in controlling scale in aqueous system and as encrustation inhibitor in detergent formulation.
According to the present invention, the units of copolymer or terpolymer which are derived from acrylamido alkyl or aryl sulphonates must be 0 - 50 % by weight. The acrylamido alkyl or aryl sulphonates in copolymer or terpolymer of the invention are represented by the following structural formula:
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wherein R is H olr methyl, R7 is H or CM alkyl, Rs is Ci_8 alkyl or phenyl M is H or metal cation.
The new monomer of the present invention of copolymer or terpolymers is alkanolamido carboxyllic acid of following formula: R

Wherein R has significance mentioned herein above Rs is H or methyl or -COOMi. R4 is H or C1-C12 alkanol or alkyl and R5 is CI-C12 alkyl.
The copolymers / terpolymers of the present invention, containing the selected units. In the selected weight ratios, have weight average molecular weights ranging from
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about 3000 to about 50000, preferably from about 10000 to about 50000 and more Preferably from about 25000 to about 50000.

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