FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION {See section 10 and rule13)
1. TITLE OF THE INVENTION HIGH EFFICIENCY LOW SLUMP LOSS SUPER PLASTICIZER BASED ON COMB SHAPED POLYCARBOXYLATE ETHER PROCESS FOR MANUFACTURE THEREOF.

2 APPLICANT (S)
(a)NAME:- Apple chemic india pvt. ltd Nagpur
(b) NATIONALITY:INDIAN
(c)ADDRESS:-24, ABHANG,CENTRAL EXCISE COLONY, RING ROAD, NEAR CHATRA PATI NAGAR CHOWK, NAGPUR-440015, 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.
4. DESCRIPTION {Description shall start from next page.)
5. CLAIMS (not applicable for provisional specification, Claims should start with the preamble — "l/we claim" on separate page)
6. DATE AND SIGNATURE (to be given at the end of last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on separate page)
Note; -*Repeat boxes In case of more than one entry.
*To be signed by the applicant(s) or by authorized registered patent agent. *Name of the applicant should be given in full, family name in the beginning . *Con.ptete address of the applicant should be given stating the postal index no./code, state and country. *StriKe out the column which is/are not applicable

1. TITLE OF THE INVENTION
High Effieiency ,low slump loss super-plasticizers based on comb shaped polycarboxylate ethers & process for manufacture thereof

2. APPLICANT(S)
a. NAME : Apple Chemie India Pvt. Ltd. Nagpur
b. NATIONALITY : Indian
c. ADDRESS : 24 'Abhang' Central Excise Colony Ring Road
Near Chatrapati Nagar Chowk Nagpur-440015

3. PREAMBLE TO THE DESCRIPTION OF THE PRESENT INVENTION
The present invention is concerned with synthesis of advanced high efficiency super-plasticizers for cement concrete based on comb shaped polycarboxylate ether as well as the process for manufacture thereof.
Concrete admixtures based on the polymers made according to the present invention exhibit properties such as decreasing the concrete viscosity.enhancing the slump retaining ability and suppressing the bleeding water & thereby improving the cement compositions, so that work becomes easy at a field handling cement paste, mortar & concrete .Advanced polycarboxylate ethers described in the present invention are copolymers containing unsaturated carboxylic acids & their salts,derivatives of the said carboxylic acids & having varying density of pendant chains containing polyalkylene glycol units having different compositions and different chain lengths.

Complete specifications: The following specifications particularly describe the inventions the manner in which it is to be performed.

4. DESCRIPTION OF THE INVENTION Background of the Invention
Fine particles such as cement grains have a tendency to flocculate when mixed with water. When they flocculate a certain amount of water gets entrapped inside agglomerates.. When flocculation of cement takes place, part of water added while mixing becomes unavailable & maintenance of workability becomes difficult & hydration of cement does not proceed properly. Plasticizers deflocculate cement particles & release the entrapped water. If one does not include plasticizers the positively & negatively charged cement particles get attracted to each other causing flocculation. The basic mechanism by which water reducing agents & plasticizers work is dispersion of cement particles by electrostatic repulsion & /or steric hinderance.
Conventional plasticizers have ionizable groups eg sulfonate, carboxylate & therefore display an overall negative charge. Cement grains when mixed with water generate mineralogical phases which have a net positive charge. Negatively charged plasticizer molecules rush towards positively charged cement particles due to electro static attraction. The plasticizer molecules thus get adsorbed on the cement particles & thereby impart an overall negative charge on the particle surface .Electrostatic repulsion between cement particles bearing negative charge & reduction in surface area in turn enables the dispersion of cement particles. For superplasticizers of earlier generations namely lignosulfonates, naphthalene sulfonates & sulfonates of melamine formaldehyde condensates, electrostatic repulsion as explained above is mainly responsible for dispersion of cement particles.The latest generation superplasticizers are based on Polycarboxylate ethers. Polycarboxylate ethers are comb or star shaped polymers wherein special features are incorporated in their backbone which enable their adsorption on cement particles.The polycarboxylate polymers further have side chains which contain polyethylene oxide groups.The backbone of PCEs function as anchors onto the cement particles while the side chains extend from the surface of cement particles & migrate into water. PCE coated cement particles thus essentially get dispersed because of the steric repulsion caused by the thickness of the adsorbed polymer layer ( steric repulsion exerted by the side chains on each other) Thus in case of PCEs the dispersion of the cement particles is due to two different components electrostatic plus steric. Of the two, the electrostatic repulsion contributes minor portion while steric hinderance is the main component.
The PCE based SPs have paved a way to major developments in concrete technology & practices. The combined benefits in concrete workability, strength & durability, undeniably constitute a Quantum Leap in concrete technology.

Super-plasticizers are extensively used to improve the performance characteristics of cement mixtures both in the fresh & hardened state. Their addition improves the rheology of cement mixtures by strongly reducing their viscosity in the fresh & in the plastic state & makes the mixtures more workable and easy to cast.
Super-plasticizers are used in concrete for three different purposes or a combination of these.
1) The addition of superplasticizers without reducing the mixing water produces flowing self compacting and self leveling concrete which completely fills the moulds even of complex shapes and in the presence of heavily reinforced components without the necessity of expensive & time consuming work of vibration. Such characteristics by reducing the risk of voids in the structures ensure the homogeneity of concrete & contribute to the improvement of reliability of the work.
2) The increase of the workability produced by superplasticizers can be used to reduce the mixing water of concrete. By this way it is possible to obtain cement mixtures which are characterized by low water to cement ratio in order to attain high early and ultimate strength & improved durability.
3) Superplasticizers can be used to reduce both water and cement at a given workability & strength, in order to improve the characteristics of hardened concrete by reducing creep, drying shrinkage & thermal strains caused by heat of hydration in mass concrete. Furthermore the reduction of cement content due to the use of superplasticizers allows clear benefits from an economical as well as environmental point of view.
The above demarcation however has become quite vague with the advent of high performance concrete & the development of advanced superplasticizers based on polycarboxylate ether chemistry. It is now possible through the use of these new products to obtain very low water cement ratio highly durable self leveling & yet quite cohesive high strength concrete . These polycarboxylate based superplasticizers are characterized by a main polymer backbone bearing ionic groups & grafted polyoxyalkylene unit containing side chains.Compared with the previous generation naphthalene sulfonate & melamine sulfonate based products polycarboxylate ether based superplasticizers provide a reduction of higher amount of water as well as adequate workability which is retained over a longer time,Better overall plastcizing effect of this class of superplasticizer is ascribed to the better dispersion of the cement grains caused by the polyoxyalkylene side chains once these polymers are adsorbed onto the cement particles. The same factor is responsible for the better retention of the workability in comparison with PNS & PMS based superplasticizers.
This new class of cement additives can be obtained by polymerizing unsaturated mono or dicarboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic..acid & their salts with monomers containing polyoxyalkylene chains of different types & or different chain lengths.

United States Patent 4,471,100 claims cement dispersants in which polyalkylene glycol mono ally! ether with a number of oxyalkylene groups in the range 1-100 is polymerized with maleic acid or anhydride and eventually with a third monomer . These copolymers show a better water reducing effect even at a small dosage level compared to the conventional cement dispersing agent based on naphthalene sulfonate & do not cause any appreciable adverse effects on the other properties of the concrete.
United States Patent 5,362,324 discloses cross-linked superplasticizers obtained by polymerizing, a) methacrylic acid, b) polyethylene glycol mono methyl ether-methacrylate & c)polypropylene glycol dimethacrylate. These polymers are characterized by low air entraining effect & show much higher water reducing effect and better retention of the workability of concrete in the fresh and plastic state in comparison with the previous generation naphthalene sulfonate based superplasticizers. Concrete mixtures containing the claimed polymers maintain 80 percent of the initial workability after 45 minutes from mixing, compared to the drop of the slump at 50 percent of the initial value after the same period of time for concrete mixtures containing traditional naphthalene sulfonate based superplasticizer.
United States Patent 5,798,425 discloses a dispersing agent for hydraulic binders obtained by polymerizing a) unsaturated dicarboxylic acid derivative , such as maleic acid maleic acid monoesters, maleic acid monoamides, maleic anhydride b) oxyalkylene glycol monoethers such as methyl polyethylene glycol monovinyl ether and c) a vinyl polyalkylene glycol, polysilaoxane or ester compound. The polymers of this invention show an improved retention of the workability without introducing very large amounts of air pores into the binding agent mixtures. Cement mixtures containing disclosed superplasticizers maintain almost the same workability after 60 minutes from mixing compared to the reduction at 55 % of the initial value after the same period of time for mixtures containing traditional melamine based superplasticizers.
Japanese patent 58-74552 first discloses a cement dispersant in which a polaikylene glycol monomethacrylic acid ester monomer with a number of oxyalkylene groups in the range 1-100 is polymerized with methacrylic acid and optionally with a third monomer. These superplasticizers gave a concrete of the same fluidity with a smaller addition compared to the known dispersants based on naphthalene sulfonates without adverse effects on compressive strength.
European patent 0846090 discloses a concrete additive comprising copolymers consisting of structural units derived from a) an ethlenically unsaturated monomer having from 25 to 300 mole oxyalkylene groups per mole of monomer, including methoxypolyethylene glycol methacrylates & adducts of allyl alcohol with ethylene oxide and b) alkyl, alkenyl or hydroxyalkyl ester of an ethelenically unsaturated mono or dicarboxylic acid including C1-C18 linear & branched methacrylates, C1-C18 linear & branched alkenyl methacrylates, C2-C6 hydroxyalkyl methacrylates and optionally a third monomer c) selected from ethlenically unsaturated mono or dicarboxylic acid. Concrete mixtures containing the claimed copolymers or mixtures of the claimed, polymers with other superplasticizers maintain more than 80 percent of the initial

workability after 120 minutes of mixing compared with the drop of the slump at less than 30 percent of the initial value after the same period of time for concrete mixtures containing traditional based naphthalene sulfonate & melamine sulfonate superplasticizers.
One of the drawbacks associated with use of polycarboxylate superplasticizers is the tendency to entrain air bubbles in the concrete during mixing due to their surface activity. As a consequence of the uncontrolled entrapment of air bubbles may produce adverse effects on the mechanical strength development & on the appearance of the concrete. In order to overcome this disadvantage defoamers are often blended with polycarboxylate superplasticizers but given the fact that these substances are almost insoluble in water they tend to separate from the polymer solution and therefore their efficiency is reduced with the time of storage Intrinsically low foaming superplasticizers are described in United States Patent 5,362,324 & US 5,798,425 both relating to defoaming agents bonded to the polymer chain. By this way the the defoaming agent is stabilized in the polymer solution & the defoaming capacity is maintained for longer time. The defoaming efficiency of these polymers can eventually be increased by the addition of external defoaming agents characterized by high stability in the polymer solutions. In particular US 5,362,324 describes a low air entraining superplasticizer obtained by terpolymerization in which polypropylene glycol dimethacrylate with molecular weight of 280 to 3100 is copolymerized with methacrylic acid & polyethylene glycol monomethyl ether methacrylate with molecular weight from 200 to 2000.
Chinese Patent 101955333 A &B specifically make claims for synthesis of a high water reducing efficiency polycarboxylic acid superplasticizer effective at low dosages & describes a method for using the same. This superplasticizer is made by simultaneous use of polyethylene glycol mono methyl ether methacrylate as well as methallyl alcohol polyethenoxy ether along with methacrylic acid plus its sodium salt along with chain transfer agent eg sodium methallyl sulfonate for controlling of molecular weight development. This patent claims a simple synthetic procedure which yields cost effective products which give stable performance.
A recently published Chinese Patent 102358774 assigned to Zhenzou Technological Co. Ltd. relates to a polycarboxylate based superplasticizer & preparation method for the same. The invention claims use of an unsaturated polyethylenoxide containing polyether along with an ethylenically unsaturated mono or dicarboxylic acid. The invention further claims a simple process, short reaction time & low energy consumption.
Chinese Patent 102924669 A & B describes a method for preparation of a comb type polycarboxylate copolymer employing unsaturated polyethylene glycol ether along with unsaturated dicarboxylic acid or its salts eg maleic acid or anhydride plus a unsaturated sulfonic acid salt which enables better solubilization of the copolymer. This patent further claims that there is no need of using deionized water & use of nitrogen gas bubbling is not essential making it very simple in terms of operation & less cost of equipments.

One recently published Chinese patent 102936110 has described a composite superplasticizer containing polycarboxylate ether copolymers along with salts of lignin sulfonic acid. This patent claims novel use of naturally renewable material & a cost efficient product having high efficiency of water reduction & better slump retaining ability.
USPatent 7,638,563 B2 granted to Messers Nishikawa et al relates to a polycarboxylic acid concrete admixture & a cement composition. More particularly this patent describes a polycaboxylate acid concrete admixture that can be applied as a water reducing agent & the like for improving the fluidity for cement compositions & a cement composition comprising the same.In this patent a polycarboxylic acid polymer obtained by monomer components containing at least three species of monomers.that is an alkyl (meth)acrylate monomer a polyalkylene glycol an unsaturated monomer & an unsaturated carboxylic acid (salt) monomer.
Clariant Corporation has filed an application for grant of a US Patent on 18th September 2008 (Application No. 2010/0216960A1) The patent application is entitled Polycarboxylate ether as Dispering agent for inorganic pigment formulations. The invention pertains to the use of macromonomers produced using DMC catalyst for the production of polycarboxylate ethers obtainable by polymerization of monomers containing an ethylenically unsaturated carboxylic acid a macromonomer containing (meth)acrylate ester having polyalkylene oxide units & at least a third monomer having ethylenically unsaturated functionality different than monomers defined as monomers 1 & 2 above.
US Patent 8,058,328B2 granted to Ueta et al. describes a cement admixture providing excellent slump retaining ability& at the same time providing excellent fluidity.The admixtures of the claimed patent enables easy working of the cement compositions.This patent relates to a cement admixture which comprises a polycarboxylic acid copolymer having a polyalkylene glycol. The said polycarboxylic acid copolymer being constituted of two or more species of copolymers with different acid values & at least one of said two or more species of copolymers with different acid values having an oxyalkylene group containing three or more carbon atoms.
As stated above the main role of the superplasticizer is to disperse cement particles which are strongly agglomerated (flocculated) when cement is contacted with water When brought in contact with water cement reacts quickly & releases ions in to the solution( essentially Na+, Ca+2, K+.S04-2, OH-) Thus a complex system evolves over a time & the influence of various parameters cannot be separately studied nor predicted theoretically Polycarboxylate ethers ( PCEs) are comb or star shaped polymers with specific molecular features.Polymers of the polycarboxylate family can be produced with almost infinite variations in their chemical structure The specific features which are tailored in the polymer enable the dispersion of cement particles. These polymers are adsorbed on the cement surface. This adsorption gives rise to electrostatic repulsion plus steric repulsion caused by the thickness of the adsorbed polymer layer. For SNF & SPs of earlier generations electrostatic repulsion is mainly responsible for cement

dispersion. On the other hand in case of PCE based SPs steric hindrance is a more effective mechanism than electrostatic repulsion In this case (PCE) the side chains, primarily of polyethylene oxide extend on the surface of cement particles & migrate into water and the cement particles get dispersed because of the steric hindrance exerted by the side chains ( extensions) on each other.
Electrostatic repulsion depends on the composition of the solution phase and the amount of the SP adsorbed (greater the adsorption, better the repulsion).higher the molecular weight lower is the adsorption. Differences in molecular architecture lead to differences in performance of polycarboxylate based ( PCE) superplasticizers. Steric repulsion between cement particles loaded with adsorbed superplasticizer molecules depends upon the quantity of superplasticizer adsorbed which in turn is determined by the length of main chain( molecular weight), as well as the length as well as density of side chains.The specific advantage of the steric repulsion effect is mainly a lesser influence of ions in the interstitial solution. The forces attaching superplasticizers on the surface of cement particles can be of different origins. Superplasticizers are ionic water soluble polymers which can form complexes with cations on the surface for example Ca+2 on cement. The interstitial cement solution has a pH between 12 -13 & the surface charge of the cement particle is lower even negative This is not favourable to electrostatic binding since superplasticizers are also negatively charged. Studies have shown that surface complexation is not dependant on the surface charge which is the main mechanism binding polycarboxylates to a surface.
In a suspension the adsorbed polymers may have two different regimes according to the degree of surface coverage.At low surface coverage the adsorbed polymers are independent of each other & we have the so called mushroom region. When the surface coverage increases the polymers overlap & a brush regime establishes. Such a regime can be expected for polymers having a relatively short backbone & comparatively longer side chains. In other words, with such polymers a more thick layer of the adsorbed polymer would form enabling them to display a better dispersing action on cement particles. Identification of types of adsorption sites on heterogenous solid surface in case of cement systems is indeed a great challenge for design of superplasticizers. Use of supplimentary cementitious materials further complicates the issue making design of a universal superplasticizer a very difficult task.
PCEs have been broadly classified into the following 2 types depending on the type of the bond joining the polymer main chain ( backbone) containing short carboxylate groups & the pendant (hanging) graft or long side chains containing polyalkylene oxide units.
Polyether type PCE( PAAPC) which are stable to alkaline environments due to insensitivity of ether linkage to alkaline conditions.
Polyester type PCE (PMAPC) which are susceptible to alkaline environments because the sensitivity of ester linkage to alkaline conditions.

Hence on the basis of insensitivity of PAAPC type PCE to alkaline conditions the same is expected to provide a better slump retention ability on comparative basis due to side chains which continue to be long. This longer slump retention is possible at low water cement ratio without affecting setting times or early strength development. The PMAPC type PCE (susceptible to alkaline environments) displays a somewhat better dispersing power in comparison with PAAPC type PCE due to the generation of negative charged carboxylate groups due to alkaline hydrolysis which would enable increased water reduction. It can further be surmised that it should be possible to arrive at better flow characteristics along with increased water reduction by using blends of type 1 & type 2 PCEs. Alternatively such products can be directly made by incorporating cross-linking monomers which get hydrolyzed by the alkaline water phase of the cement paste & in turn get converted to carboxylic acid groups.Due to the freshly generated carboxylic acid groups PCE are absorbed on the cement particle. Due to dispersion of the particles the paste retains fluidity & workability for longer periods. The low slump loss is obtained in case of PCE with increased number of protruding side chains which help to prolong the dispersion of hydrated cement particles by steric hinderance..
Summary of the Invention
The present invention is concerned with synthesis of advanced high efficiency super-plasticizers for cement concrete based on comb shaped polycarboxylate ether as well as the process for manufacture thereof.
Concrete admixtures based on the polymers made according to the present invention exhibit properties such as decreasing the concrete viscosity enhancing the slump retaining ability and suppressing the bleeding water & thereby improving the cement compositions so that work becomes easy at a field handling cement paste, mortar & concrete.Copolymers of the present invention are made with a comparatively simpler set-up & does not require passage of a inert gas such as nitrogen during the conduct of polymerization. The time required to generate the products is much shorter as compared to other PCEs & also the reaction is conducted at a somewhat low temperature. Due to these advantages the process of manufacture & the resulting copolymers become cost effective for the user due to higher efficiency for water reduction & retention of slump & workability characteristics for longer time.
Advanced polycarboxylate ethers described in the present invention are copolymers containing unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid & their derivatives eg anhydride and their salts, As a comonomer methoxypolyethylene glycol ethers containg unsaturation as a carbon carbon double bond &omega alkoxypolyalkyleneglycol ether or omega alkoxy poly alkylenoxyether acrylic acid or methacrylic acid esters made by reaction of corresponding acids with unsaturation containing polyalkyleneoxy ethers having alkylene oxide of different molecular weights. The copolymers of the said invention also have monomers containing sulfonic acid or their salts. These polymers also contain groups having either hydrophobic groups or hydrophilic groups & simultaneously displaying chain

transferring ability. Other monomers specifically esters or amides of the unsaturated mono carboxylic acid can also be included to obtain the desired & specific properties..
Detailed description of the invention :
The polymers of the present invention can be made by solution polymerization technique which enables obtainment of somewhat controlled molecular weights. Organic solvents eg aromatic hydrocarbon & esters of aliphatic acids as well as water can be used as solvent.Adequate quantity of the selected solvents to obtain the product copolymers as solutions having non volatiles in the range of 30 to 50 percent more specifically to 35 to 45 percent non voalatiles & more specifically to obtain 38 to 42 percent active concentration.
As monomer a) unsaturated ethers containing polyalkenoxy moieties having the chemical structure as per Formulalwherein R1, R2 & R3 are either H or CH3 & n varies from 5 to 120. The proportion of monomer a preferably lies in the range from 5 to 95 percent of total of monomers a, b, c, d & optionally e add up to 100. As a typical example omega methoxypolyethyleneglycol (meth) allyl ether having hydroxyl value from 10 to 50 are as well as omega methoxy poly ethyleneglycol polypropylene glycol ether are quite suitable.
These copolymers further contain as an essential ingredient mono or di ethylenically unsaturated carboxylic acid & or its alkali metallic salt eg Na+ or K+ as monomer b & the proportion of monomer b varying from 5 to 95 % of the copolymer wherein total of monomers a,b, c, d & optionally e add to 100. Typically suitable examples of monomer b are ethelenically unsaturated (meth)acrylic acids or their sodium salts eg sodium methacrylate.
As monomers c in the copolymerization reaction which is present at a comparatively very low proportion varying from 0.5 to 2.5 % of total of a,b,c,d & optionally e are sulfonic acid or their salts possessing chain transferring ability & also displaying hydrophilic behavior in turn controlling the molecular weight of the obtained copolymer. As a typical monomer c one may make use of thioglycolic acid , 2or 3 mercaptopropionic acid. Alternatively one could also use a hydrophobic unsaturated mercaptans.
As an important ingredient of the copolymer monomer d is present in the proportion of 0.5 to 10 % of total an unsaturated sulfonic acid or its alkali metal salt. The component d serves mainly a dual function of imparting a negative charge at a comparatively low pH & also increasing the aqueous solubility of monomer a which in turn is governed by the hydroxyl value & the composition of monomer a ,which provides water loving polyalkyleneoxide units & in turn solubility in water at a comparatively lower temperature. As typical examples of monomers d are alkali metal salts of (meth) allyl sulfonic acid, 2- methyl- 2-acrylamidomethane sulfonic acid, styrene sulfonic acid etc.

As optionally used monomers e one can employ ( meth) acrylic acid amides or esters, these esters also may contain poly alkylene oxide units & the proportion of monomer e in the total composition preferably lies in the range of 0 to 30 percent more preferably from 0 to 20 percent & still more preferably 0 to 15 % of total a,b, c, d & optionally e. typical as monomers e are (meth) acrylamide, ethyl or butyl acrylate, polyalkyleneoxide containing acrylic acid or methacrylic acid ester having hydroxy! value in the range of 10 to 50.Acrylamide & ethyl (meth)acrylate & methyl methacrylate are quite suitable.
As an initiator for radical polymerization both thermally decomposable salts of peroxy acids eg persulfates of ammonium, sodium or potassium are quite suitable. Alternatively redox pair type catalysts eg hydrogen peroxide along with ascorbic acid, potassium persulfate along with sodium metabisulfite, tertiary butyl hydroperoxides either alone or in combination with sodium metabisulfite can be advantageously employed.
Typically the copolymerization of the present invention is carried out in an aqueous medium. Some or all of the monomers are added into water such that the solution has a concentration of about 25 to 35 % on solid basis at ambient temperature & the reactor temperature raised to around 40 to 90 degrees C in a matter of 30 to 60 minutes. Once the desired temperature is attained & when the contents have been properly dissolved in water the aqueous solution of monomer is added to the reactor in a drop-wise manner over a period from 1 to 5 hours. Simultaneously an aqueous solution of the initiator is also added to the reactor in a dropwise manner through a separate addition port over a period from 1.5 to 5.5 hours.During the entire addition process of monomers & the initiator solution the reactor is stirred & maintained at the temperature between 40 to 90 degrees C. It is to be ensured that addition of the initiator solution continues for about 30 to 60 minutes after the addition of monomer solution is completed.. The stirring & heating of the reactor is continued for about from 0.5 hours to 1.5 hours to ensure that unreacted free monomer concentration in the product is brought down to less than 0.5 % as acrylic acid Then the temperature of the reactor is brought down to ambient temperature. At this stage the pH of the reactor is typically around 2.0 to 3.0. An aqueous solution of sodium hydroxide ( concentration in the range from 30 to 50 percent) is added to the reactor in a drop-wise manner & the pH of the contents is brought to about 6 +-1. The obtained polymer is characterized by its appearance displaying very light to slight yellow color its non volatile content & flow behavior ( viscosity).
The following examples are representative in the sense that they describe the preparation & performance characteristics of the produced copolymers without limiting structural components to those used in the quoted examples. In the same way the temperature for conducting the polymerization reaction can vary preferably from 40 to 100 degrees C, more preferably from 50 to 90 degrees c & most preferably from 60 to 80 degrees C. Time for dropping of mixed monomer solution as well as that of the catalyst solution varies preferably from 0.5 to 5.5 hours & more preferably from 1 to 4.5 hours & most preferably from 1.5 to 3.5 hours.

It will be quite clear to those skilled in the art of making concrete of different strengths & for different specific purposes eg ready mixed concrete, self compacting concrete, precast concrete etc. that the superplasticizers of the above invention can be incorporated along with retarding, accelerating, shrinkage controlling, defoaming additives to obtain admixtures for the desired application resulting in concretes of desired workability & strength characteristics.
Examplel : 0.039 moles of alpha allyl omega methoxypolyethyleneoxyether having a hydroxyl value of (25,. +-0.5) & unsaturation value (0.37+-0.05) & 0.0064 moles of sodium methallyl sulfonate & 113 ml of deionized water were charged in a round bottom flask equipped with a mechanical stirrer, a condenser, & 2 separate addition funnels & an electrical heating mantle.The contents of the reactor were stirred to completely dissolve allyl methoxypolyethyleneoxyether. The reactor temperature was raised to about 70 degrees C in a matter of about 30 minutes. Half an hour after attainment of 70 degrees to the reactor were simultaneously added solutions of 0.121 moles of acrylic acid, 0.004 moles of acrylamide & 0.00084 moles of thioglycolic acid in about 25 ml water & 0.65 grams of ammonium persulfate in about 15 ml water. The addition of monomer solution was accomplished in about 60 minutes while the addition of APS solution took about 90 minutes. After complete addition of the solutions of monomer & the initiator the reactor was maintained at 70 degrees C for about 60 minutes. The reactor was then cooled down to ambient temperature &subjected to dropwise addition of 50 % sodium hydroxide solution to attain a pH between 6+-1.The obtained product was characterized by its very light to slight yellow appearance, solid contents & flow behavior ( viscosity by B4 ford Cup flow out time)
Example 2 : Exactly the same procedure for synthesis was employed as given in Examplel above. However the amount of allyl polyethlenoxyether employed was 0.0448 moles instead of of 0.0390 moles used in Example 1
Example 3 : Exactly the same procedure for synthesis was employed as given in Example 1 above except the fact that 0.0605 moles of allyl polyethelenoxy ether was used instead of 0.0390 moles employed in Example 1 above.
Example 4 : Exactly same procedure of synthesis as given in Example 3 was used to make a polymer substituting sodium methallyl sulfonate with 2- methyl- 2-acrylamidomethyl-propane sulfonic acid in the form of its sodium salt ( This monomer is available as a 50 % aqueous solution ) accordingly quantity of water used for dissolution of allyl polyethelenoxy ether was decreased .
Example 5 : Exactly same procedure was employed for synthesis as given in Example 1 but allyl polyethenoxyether was used at 0.0267 moles, acrylic acid 0.347 moles, methoxy polyethyleneglycol methacrylate 0.030 moles &sodium methallyl sulfonate at 0.064 moles

Example 6 : Exactly same procedure for synthesis was employed as given in Example 1 above except the fact that acrylic acid was used at 0.131 moles.
Example 7: Exactly same procedure for synthesis was employed as give in Example 6 above except the fact after complete addition of solution of the initiator & monomers the reactor was maintained at 70 degrees C for about 2 hours.
Example 8 ; Exactly same procedure for synthesis was employed as given in Example 6 above except the fact that the reactor was maintained at 70 degrees C for about 3 hours after completion of addition of monomers & the solution of the initiator.
Example 9: Exactly same procedure for synthesis was employed as given in Example 6 above except the fact that the reactor was maintained at 70 degrees C for about 4 hours after completion of addition of solution of initiator & the monomers.
Example 10: Exactly same procedure for synthesis was employed as given in Example 6 above except the fact that the reactor was maintained at 70 degrees C for about 5 hours after completion of addition of monomers & the solution of the initiator.

5. Claims :
1) We claim a high efficiency polycarboxylate ether based superplasticizer which
enables high range of water reduction besides providing adequate workability to
cement compositions for up-to 2.5 hours employing as components monomers a,
unsaturated ethers containing polyalkenoxy moieties having the chemical
structure as per Formula 1wherein R1, R2 & R3 are either H or CH3 & n varies
from 5 to 120 in the range from 5 to 45 % more preferably from 10 to 40 % &
most preferably from 15 to 35 %
These copolymers further contain as an essential ingredient mono or di ethylenically unsaturated carboxylic acid & or its alkali metallic salt eg Na+ or K+ as monomer b.The proportion of monomer b is in the range of 40 to 90 % of total of a,b, c, d & optionally e (as 100%) more preferably from 45 to 85 % & most preferably from 50 to 80 %. These polymers also contain monomers c in the copolymerization reaction & which is present at a comparatively very low proportion varying from 0.5 to 2.5 % of total & are hydrophobic mercaptans or thiols or hydrophilic sulfonic acid or their salts & possessing chain transferring ability and in turn controlling the molecular weight of the obtained copolymer. As an important ingredient of the copolymer monomer d is present preferably in the range of 0.5 to 10 % more preferably froml to 8 % & most preferably from 2 to 7 % of total an unsaturated sulfonic acid or its alkali metal salt. The component d serves mainly dual function of imparting a negative charge at a comparatively low pH & also increasing the aqueous solubility of monomer a which in turn is governed by the hydroxyl value & the composition of monomer a ,which provides water loving polyalkyleneoxide units & in turn solubility in water at a comparatively lower temperature. As optionally used monomers e one can employ ( meth) acrylic acid amides or esters, these esters also may contain poly alkylene oxide units & the proportion of monomer e in the total composition preferably lies in the range of 0 to 30 percent more preferably from 0 to 20 percent & still more preferably 0 to 15 % of total.
The high efficiency superplasticizer based on polycarboxylate structure is synthesized by dissolving desired quantities of components a, &c in water so that the concentration is in the range of 30 to 50 % & the reactor is heated to the desired temperature in the range from 40 to 90 degrees C. Half an hour after attainment of desired temperature the aqueous solution of the remaining components b, d & optionally e as well as the solution of catalyst is separately fed at the same time in a matter of 0.5 to 5.5 hours. The contents are stirred for a time from 0.5 to 1.5 hours after completion of addition of both the solutions. The reactor is cooled down to ambient temperature & then neutralized by dropwise addition of aqueous solution of sodium hydroxide pH is adjusted in the range of 5 to 7.
2) We claim that high efficiency Polycarboxylate ether based superplasticizer
prepared according to claim 1 contains preferably alpha allyl omega methoxy
polyalkenoxyether (as monomer a) having molecular weight in the range of

800 to 2000 & wherein the proportion of monomer a lies in the range of 15 to 30 %.
3) We claim that high efficiency Polycarboxylate ether based superplasticizer prepared according to claim 1 contains preferably ( as monomer e), omega methoxy polyethylene glycol methacrylate having a molecular weight in the range of 800 to 2000 & wherein the proportion of monomer e lies in the range from 15 to 30 %
4) We claim that high efficiency Polycarboxylate ether based superplasticizer prepared according to claim 1 contains preferably ( as monomer c) a chain transfer agent preferably thioglycolic acid & its proportion lies in the range from 0.1 to 2.5%
5) We claim that high efficiency Polycarboxylate ether based superplasticizer prepared according to claim 1 preferably utilizes either a thermally decomposable radical generator such as ammonium persulfate or redox type pair of tertiary butyl hydroperoxide & sodium metabisulfite as initiator.
6) We claim that high efficiency Polycarboxylate ether based superplasticizer prepared according to claim 1 preferably employs water as a solvent for conducting the polymerization.
7) We claim that high efficiency Polycarboxylate ether based superplasticizer prepared according to claim 1 wherein the reaction is preferably conducted in the range of 60 to 80 degrees C.
8) We claim that high efficiency polycarboxylate based superplasticizer prepared according to claim 1 wherein the time of addition of combined monomer solution & catalyst solution is preferably in the range of 1.5 to 3.5 hours.

Data on Superplasticizer samples
Sample No. Mini slump data 0.7 % bowc

Initial 60Min 120 Min
Example1 147 145 113
Example2 122 150 105
Example3 110 144 120
Example4 154 172 161

Data of admixture M-60concrete
M60 Concrete dataO.6% bowc
Sample No. Initial 60 Min 120 Min 7 day CCS in Newton
Examplel Collapse 150 120 40.3 N
Example2 Collapse 40 - 42.6 N
Example3 170 160 80 53.8 N
Example4 120 150 130 42.6 N

Data of admixture M-30concrete
M30 Concrete data 0.5% bowc
Sample No Initial 30 Min 60 Min. 7day CCS in Newton
Example 5 40 40 50 27.1N
Example 6 160 110 60 30.3 N
Example 7 110 60 40 24.6 N
Example 8 140 120 80 24.8 N
Example 9 130 110 90 26.3 N

Concrete Mix Design used ir i the trials
M-60 M-30
Cement 5.737 Kgs 4.380 Kgs
Water 1.638 Kgs 1.950 Kgs
20 mm 7.710 Kgs 11.340 Kgs
10 mm 7.687 Kgs 3.780 Kgs
Sand 6.087 Kgs 9.380 Kgs
Total 27.759 Kgs 30.830 Kgs
Admixture 0.6% BWOC 0.5% BWOC
**based on the weight of Cement

Details of the inventors &assignee
Inventors: 1) Dr Madhusudan M Bhagwat
2) Mr. Vivek Naik
Both of Apple Chemie India Pvt. Ltd.
Assignee : Apple Chemie India Pvt. Ltd.,24 "Abhang"Central Excise Colony, Ring Road,NearChhatrapati Nagar Chowk, Nagpur-440015 (India)