FORM -2
THE PATENANTS ACT, 1970
(39 OF 1970)
COMPLETE SPECIFICATION (Section 10; Rule 13)
Title:- A process of manufacturing nanocomposite material
Pankaj Ranjeet Singh Crystal Nanoclay Pvt Ltd
Date: /1/2007
The following specification particularly describes the nature of this invention and the manner in which it is to be performed

i:n:i.noi;i IF. INVENTION
'Hie prcsciil -,r.,■■.■IIU'OII is directed to make nanocompositc material having improved mechanical, barrier, and heat resistance properties. The present invention gives a economical process of producing ~ nanocompositc which consists of a polymer such as polyamide and a layered silicate clay which has been uniformly dispersed into said polymer.
2. Background of the Invention and I'rioi art:
Organically modified clays, also called organoclays, have been used for many years as rheological additives for solvent based systems. They are usually produced by making a water dispersion of a phyllosilicatc clay, usually a smectite clay, and adding to it a quaternary ammonium salt of a long chain fatty acid to produce an organically modified clay by cation exchange reaction and adsorption. The reaction may cause the organoclay to coagulate from the water dispersion which allows for its isolation by filtration and washing. Similarly, organoclays can be made without water by extrusion mixing, with heat and shear, smectite clay and the quaternary ammonium compound or compounds with no water or other solvent being present.
Polymers, resins and plastics containing clay additives have recently become widely used as replacements for heavier steel and other metal products, especially in the field of automotive manufacturing. They have also found use in a growing number of other areas, including as bridge components and as replacements for heavier steel parts in ship construction. Using extrusion and injection molding, a nylon matrix, for example, has been successfully reinforced with smectitc-typc clays (and organoclays based on the smectite clays, bentonitc and hectorite) dispersed therein to form molecular composites of nylon and finely dispersed silicate clay platelet layers. Such products, often called nanocomposites, have enhanced structural, tensile, impact and flcxural strength.
The behavior of the resultant plastic/clay product (or naiwcomposite) is qualitatively different from that exhibited by the plastic, polymer or resin alone and has been attributed by some workers in the field to the confinement of the matrix chains between the clays millions of microscopic layers. It has long been known that bentonitc and hectorite are clays which arc composed of flat silicate platelets of a thickness no more than about one nanometer.
'The nanocompositc products created to date have important commercial applications not only in the applications discussed above but also in diverse areas such as where ultrathin polymer films confined between adsorbed surfaces are involved. These uses include polymer composites for polymer adhcsivcs and films including polyethylene.
The clays used arc typically smectite clays which are layered phyllosilicates. Smectite clays possess some structural characteristics similar to the more well-known minerals talc and mica. Their crystal structures consist of two-dimensional layers formed by fusing two silica tctrahedral sheets to an edge-shared dioctahedral or trioctahedral sheet of either alumina (for example bentonite) or magnesia (for example hectoritc)--each of the different smectite clays having somewhat different structures. Stacking of these layers in nature in depths of hundreds or more caused by ionic and weak Van der Waals forces leads to voids or chambers between the separate layers. These chambers are occupied by cations which balance the charge deficiency that is generated by isomorphous substitution (often called disharmonies) within the platelet lattices.
Nanocomposites are most often prepared today using organically modified, silicates or organoclays produced by a cation exchange' reaction between the silicate and an alkylammonium salt (usually quaternary ammonium compounds). The alkyl cations exchanged onto the natural clay platelets render the hydrophilic clay organophilic and this transformation makes the clay more easily dispcrsible into the polymer or plastic. Although excellent sorbents for some organics, natural bentonite and hectorite are
themselves very hydrophilic.

Polymer-clay n.mocomposites have received much attention lately due to their potential to improve polymer properties, including gas barrier, heat deflection temperature, and modulus.
U.S. Pat. No. 4.7/9.007; 4,810,734; and 5,385,776 discloses composite materials comprising a polyamide matrix and a well dispersed, layered silicate material that is incorporated during polymerization and imparls high mechanical strength and excellent high temperature properties.
U.S. Pat. No. 5,385.776 discloses composite materials comprising a Nylon-6 matrix and a minor amount of a layered silicate material that is incorporated during melt extrusion and imparts rapid nucleation of the polyamide into the gamma crystal structure thereby improving modulus and resistance to plasticization by water.
U.S. Pat. No. 4.810.734 discloses nylon composites comprising a layered silicate material that has been treated with certain organic ammonium compounds and incorporated by synthesis using a dispersing aid.
PCX application WO 93/04117 discloses composite materials comprising a polyamide matrix and a layered silicate material that has been modified with certain primary or secondary organic ammonium compounds incorporated during melt extrusion and impart improved modulus to the polymer composite.
Representative U.S. Pat. No. 4,739,007 and 4,810,734 to Toyota describes a different process for producing a composite material which comprises a step of contacting a layered smectite clay mineral having a cation exchange capacity of up to 200 milliequivalents per 100 g with a swelling agent in the presence of a dispersion medium, thereby forming a complex which has the property of being swollen by a molten monomer of a polymer, and a polymerization step of polymerizing said monomer in said mixture. The "swelling agent" used is one which has both an onium ion and a functional group capable of reacting with a polymer. Preferred swelling agent described in the patents are amino acids preferably 12-amino dodecanoic acid.
However, 12-aminododecanoic acid is a costly chemical which increase the cost of nanocomposite significantly.
In the present invention, we have discovered the swelling agent or intercalant, which are not only cheaper in cost but also facilitate the exfoliation of clay platelets and impart enhanced properties to polymer matrix.
Summary of the invention:
The main objective of the present invention is to provide a economical process of producing the nanocomposite by using swelling agent of the present invention which are much cheaper than the swelling agent used by toyota inventors.
In the present invention, I have discovered the swelling agents which contains amine as well as carboxilic acid group and which are cheaper than conventional amino acids and are also easy to prepare.
The process of the present invention for producing a nanocomposite material comprises a contacting step of contacting a layered clay mineral having a cation exchange capacity of 50 to 200 milliequivalents per 100 g with a swelling agent in the presence of a dispersion medium. Swelling agent undergo ionexchange reaction with the inorganic ions of the silicate layer and is absorbed in the spacing of the clay layers to give a complex which is also called as organoclay. In the next step, above complex or organoclay is swelled with monomer and finally the monomer swelled with the said swelling agent is polymerized to give nanocomposite. Nanocomposite obtained show exceptionally improved properties such as mechanical, barrier and heat resistance properties.

Detailed Description of the Present Invention:
The main objective of the present invention is to use swelling agents which arc economical than amino acids such as I 2-amino dodeeanoic acid. Swelling agent used in the US patent. 4,739,007 and 4.8T0.734 are amino acids preferably I 2-amino dodeeanoic acid. However, 12-aminododecanoic acid is a costly chemical and hence this increase the cost of nanocomposite significantly.
In the present indention we have used the swelling agent which arc much economical than the above said amino acids.
inlercalants or swelling agents of the present invention can be described by structure 1 as given below.

Where Ri and R: can be:
1. Any liner or branched chain alkyl group of I to 24 carbon.
2. Any cyclic group of I -24 carbon.
3. Any aromatic group of I -24 carbon.
4. Any combination of above.
Intercalant of structure-1 can be easily prepared by reacting equimolar amount of organic di amine with di carboxilic acid.
Typical example of intercalants of structure-1 are given as below:

Typical reaction for making intercalant of structure-1 can be given as follows:

This can be easily obtained by reacting eqimolar amount of hexamethyl dicarboxilic acid with hcxamethylcnc diamine on equimolar ratio.
In the same way wc can prepare other intercalants by taking different di-carboxilic acids and di-amincs. Hence, according to main objective of the invention, any swelling agent or intercalant which can represented by structure -I will be the suitable swelling agent of the present invention.
The polymer matrix in the composite material of this invention is a resin containing polyamide, namely, a polyamide or a mixture thereof with other polymers. The polyamide herein means any polymer containing amide bonds (-CONH-), for example, nylon-66, nylon-6 and nylon 11. The greater the proportion of polyamide in the polymer matrix, the more marked will be the effects achieved by this invention; however, the effects of this invention are still apparent even when the proportion of polyamide is 10 wt%.
The clay mineral used in this invention is any clay mineral (both natural and synthesized) having a cation-exchange capacity of 50 to 200 milliequivalent/IOOg. Typical examples include smectite clay minerals (e.g., montmorillonite, saponite, beidellite, nontronite, hectorite and stevensite), vermiculite and halloysitc. With a clay mineral whose cation-exchange capacity exceeds 200 milliequivalent/100 g, its interlayer bonding force is too strong to give intended composite materials of this invention. If the capacity is less than 50 milliequivalent/100 g, on the other hand, ion exchange or adsorption of swelling agent (comprising organic or inorganic cations), which is an essential step in the process of this invention, will not be

sufficient, making it difficult to produce composite materials as intended by this invention. It is preferable to grind the clay mineral before use into a desired shape and size by means of a mixer, ball mill, vibrating mill, pin mill or jet mill.
The amount of silicate layers dispersed in said polymer matrix is preferably in the range from 0.5 to 150 pans by weight per 100 pans by weight of the polymer matrix. If this amount is less than 0.5 parts, a sufficient reinforcing effect cannot be expected. If the amount exceeds 150 parts, on the other hand, the resulting product is powdery interlayer compound which cannot be used as moldings.
Process of manufacturing the nanocompositc material consists of three steps which arc described in details as given below:
The first step is to bring a swelling agent into contact with a clay mineral having a cation-exchange capacity of 50 to 200 milliequivalcnt per 100 g of the clay mineral, thereby adsorbing said swelling agent on said clay mineral and forming a complex that can be swollen by a polyamidc monomer at temperature higher than the melting point of that monomer.
This can be accomplished by immersing said clay mineral in an aqueous solution containing said swelling agent, followed by washing the treated clay mineral with water to remove excess ions, or by mixing an aqueous suspension of said clay mineral with a cation-exchange resin previously treated with said swelling agent, thereby effecting ion-exchange operation.
In the preferred method of contacting, clay is dispersed into dispersing medium at 1-90 percent concentration of clay preferably 1-5 percent concentration of clay and more preferably 2-3 percent concentration of clay on weight basis. Temperature of clay slurry is maintained at 50-90 degree centigrade preferably 65-80 degree centigrade. Swelling agent is taken separately into dispersing medium and to convert amine group of swelling agent into onium ions, hydrochloric acid is added into swelling agent. The above swelling agent slurry is transferred into clay slurry and tempcrarture is maintained at 65-80 degree centigrade. Vigorous stirring is given to system and reaction is continued for nearly 45minutes. Thereafter, precipitate is filtered, washed, dried and grounded to get the complex which is called organoclay. The swelling agent expands the interlayer distance of the clay mineral, thereby permitting the clay mineral to take monomers into the interlayer space. It is a compound having an onium ion and a carboxyl group. Onium ion takes part in ion exchange reaction and it replaces the inorganic ions present at clay platelets -such as sodium, ion calcium ion, magnesium ions etc. and hence is attached with the clay platelets. Carboxyl group of the swelling agent interact with amine group of polyamide monomer and hence helps in diffusing the monomer into layers of clay platelets in second step and also it helps in ring opening and polymerization in step-3.
The dispersion medium disperses the layered silicate in the dispersion medium, thereby allowing the layered silicate to easily come into contact with the swelling agent. The kind of the dispersion medium differs depending on the clay mineral, swelling agent, and monomer to be used. The preferred dispersion medium is one which disperses the clay mineral uniformly and exhibits good miscibility with the swelling agent and monomer.
Examples of the dispersion medium include water, methanol, ethanol, propanol, isopropanol, ethylene glycol, 1,4-butancdiol, glycerin, dimethyl sulfoxide, N,N-dimethylformamide, acetic acid, formic acid, pyridine, aniline, phenol, nitrobenzene, acctonitrile, acetone, methyl ethyl ketone, chloroform, carbon disulfide, propylene carbonate, 2-methoxyethanol, ether, carbon tetrachloride, and n-hexane. They are used alone or in combination with one another. One or more than one kind of dispersion medium should preferably be selected from water, methanol, and ethanol in the case where the clay mineral is montmorillonitc and the polymer is polyamide.
The second step in the process of this invention is to mix a polyamide monomer with the complex, or organoclay obtained in the first step.
The polyamidc monomer used in this step is a material which will form the matrix polymer in the composite materials of this invention. Illustrative examples include amino acids such as 6-amino-n-caproic

acid and 12-aniino-dodecanoic acid, nylon salts such as hexamcthylencdiaminc adipate, and lactams such as .cpsilon.-caprolactam and caprylolactam.
Mixing of the complex and polyamidc monomer is effected by using a power-driven mortar, vibration mill or the like.
I lie final step is to polymerize the mixture obtained in the mixing step above by heating it to a prescribed temperature, thereby giving an intended composite material of this invention (polymerization step). The mixture obtained in the mixing step may be immediately heated to cause polymerization. However, the better way is to keep the mixture at a temperature slightly above the melting point of the polyamidc monomer for a certain period of time to ensure even dispersion of the clay mineral in the monomer.
When no base catalyst and accelerator are used in the preceding mixing step, polymerization proceeds in the cationic mode, with the swelling agent present in the system acting as catalyst.
This type of polymerization can be carried out in the temperature range from 200.degrce. to 300.degree. C, but a temperature between 250.dcgree. and 300.degree. C. is preferable for rapid progress of polymczation. Suitable polymerization time, though different depending on the type of swelling agent and polymerization temperature, is preferably in the range from 5 to 24 hours. To be more specific, polymerization at 250.degree. C. can be put to completion in about five hours when an organic ion is used as swelling agent, but it requires 10 to 24 hours for completion when an inorganic ion is used.


Claims:
A Process of manufacturing nanocomposite material comprising the following steps:
a. Contacting a swelling agent having the structure-1:
Wherein Rl and R2 are any linear or branched chain alkyl group of 1-24 carbon, and /or any cyclic group of 1-24 carbon and/ or any aromatic group of 1-24 carbon and /or combination of threof, with a Phyllosilicate or layered silicate clay mineral in presence of dispersion medium thereby forming a complex, which is also called organoclay, and which has property of being swollen by molten monomer of a polymer or a mixter of said monomer and a dispersion medium.
b. Mixing the said complex with a said monomer of Polymer followed by a process of Polymerization for polymerizing the said monomer containing the said complex to form Nano-composite having improved Drooerties.
2. A Process of as claimed in claim 1, wherein layered clay material comprises montmorillonite, hectorite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, or a mixture thereof.
3. A Process of as claimed in claim 1, wherein layered clay material comprises sodium montmorillonite or sodium bentonite.
4. A Process of as claimed in claim 1, wherein said polymer matrix is polyamides formed by the polymerization of an amino acid or a derivative thereof.
5. A Process of as claimed in claim 4, wherein said Polyamides are Nylon 6, or Nylon 12.
6. A Process of as claimed in claim 1, wherein the preferred dispersion medium are water, methanol, ethanol, propanol, ethylene glycol, 1,4-butanediol, glycerin, dimethyl sulfoxide, N,N-dimethylformamide, acetic acid, formic acid, pyridine, aniline, phenol, nitrobenzene, acetonitrile, acetone, methyl ethyl ketone, chloroform, carbon disulfide, propylene carbonate, 2-methoxyethanol, ether, carbon tetrachloride, and n-hexane. These dispersion mediums can be used alone or in combination.
7. A Process of as claimed in claim 1, wherein the clay is dispersed in the dispersion medium at 1-90% concentration, preferably 1-10% concentration and more preferably 1-5% concentration.
8. A process of as claimed in claim 1, wherein the amine group of swelling agent is converted into onium ion by reacting it with A acid like hydrochloric acid, sulfuric acid etc. either separately before mixing it with clay slurry or simultaneously while mixing it with clay slurry.
9. A process of as claimed in claim 1 to 8, wherein clay slurry temperature is maintained at 50-90 degree centigrade, preferably at 65-80 degree centigrade during its reaction with swelling agent followed by the processof filtration, washing, drying and grinding to get the final powdered complex which is also called organoclay.
10. A process of as claimed in claim 1 to 9, wherein the said organoclay is mixed with monomer of polymer followed by polymerization of said organoclay mixed monomer to yield Nanocompoite having improved mechanical, thermal and barrier properties.
II .A process of manufacturing said nanocomposite material such as here in described with reference to foregoing examples.

TITLE
Polymer clay nantocompositc with improved properties and a economical process of producing the same.
Abstract
This invention relates to polymer clay-nanocomposite comprising a layered silicate clay material swelled with organic cations and polymer matrix. The process of the present invention consists ofcontacting the layered clay mineral with a swelling in presence of a dispersion medium thereby forming a complex called organoclay, mixing said organoclay with a monomer and polymerizing said monomer contained in said
mixture.