Title of Invention	"A PROCESS FOR PREPARATION OF CHLORINATED RUBBER-POLYURETHANE SEMI-INTERPENETRATING POLYMER NETWORK COMPOSITION"
Abstract	This invention is relates to a process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition. According to the process, the castor-oil is first modified by mixing 1-5% polyethylene glycol and 6-9% glycerol. The modified castor-oil is mixed with chlorinated rubber resin dissolved in an organic solvent like toluene, xylene etc. To the above solution Methylene bis 4, 4' Diphenyl Disocyanate (MDI) is added with stirring followed by curing for 24 hours at ambient temperature.

Title of Invention

"A PROCESS FOR PREPARATION OF CHLORINATED RUBBER-POLYURETHANE SEMI-INTERPENETRATING POLYMER NETWORK COMPOSITION"

Abstract

This invention is relates to a process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition. According to the process, the castor-oil is first modified by mixing 1-5% polyethylene glycol and 6-9% glycerol. The modified castor-oil is mixed with chlorinated rubber resin dissolved in an organic solvent like toluene, xylene etc. To the above solution Methylene bis 4, 4' Diphenyl Disocyanate (MDI) is added with stirring followed by curing for 24 hours at ambient temperature.

Full Text	FIELD OF INVENTION This invention relates to a process for the preparation of chlorinated rubber-polyurethane semi interpenetrating polymer network composition. PRIOR ART A large variety of materials are used to absorb the mechanical vibrations originating from the machines. These materials are placed between the machine and the floor. These materials basically comprise of plastic, rubber and paste in the form of film, sheet, block, encapsulating materials etc. depending upon their use. An improved type of compositions, for absorption of mechanical vibrations, are special rubber blends prepared through interpenetrating polymer network technique. An interpenetrating polymer network (IPN) composition is a new class of polymer blend wherein one polymer is synthesised in the immediate presence of other polymer. However, these IPN compositions used to absorb the mechanical vibrations, known in the art, generally suffer from the following disadvantages. A primary disadvantage is such known IPN compositions are useful for absorption of mechanical vibrations for a limited range of temperature only. Another disadvantage is that these compositions are useful only over a narrow range of frequencies of mechanical vibration. A further disadvantage is that such compositions suffer from high oil swellability thereby adversely affecting their efficiency over a period of time. A still further disadvantage is that these compositions are capable of absorbing only limited amount of mechanical energy. OBJECTS OF THE INVENTION Primary object of the present invention is to provide a process for preparing chlorinated rubber -polyurethane semi-interpenetrating polymer network (IPN) composition which is based on castor oil. Another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which absorbs mechanical energy over wide temperature range from 25 to 85 ° C. Still further object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which has a high damping factor for mechanical vibrations. Yet another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which works over a wide range of frequencies from 1 Hz to 10 KHz. Still another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which has least oil swellability thereby maintaining the stability of the composition over a period of time. Yet further object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which can be formed in different shapes such as film, sheet, slab and encapsulant. Yet another object of the present invention is to provide a process for preparing chlorinated rubber-polyurethane semi-interpenetrating polymer network composition which is cheaper, simple and easy to adopt. STATEMENT OF INVENTION According to this invention there is a process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition, characterized by the step of: a) mixing modified castor oil with chlorinated rubber resin dissolved in a solvent, wherein 1-5% by weight of Polyethylene glycol 200, 6-9% by weight of glycerol and 86-93% by weight of castor oil is heated at 160°C with continuous stirring for 7 hours under intermimitent vacuum of 3-4 mm of Hg to obtain modified castor oil; b) mixing of methylene Bis 4,4' Diphenyl Disocynate (MDI) to the mixture of modified castor oil and chlorinated rubber resin; and c) curing as herein described of mixture. In accordance with the present invention, the process for preparing chlorinated rubber polyurethane semi-interpenetrating polymer network composition which has high damping factor for mechanical vibrations. The proposed material has high damping factor for the mechanical vibrations pertaining to a wide range of frequencies from I Hz to 10 kHz and is effective over a wide range of operating temperatures from 25 to 85°C. The composition can be formed in different shapes such as film, sheet, slab, encapsulant thereby enhancing its applications. The proposed material has least oil swellability and as such it does not adversely affect the stability of the composition over a period of time. The process is simple and cheaper and easy to adopt. The process comprises the steps of preparation of modified castor oil, mixing of modified castor oil with chlorinated rubber resin, mixing of methylene bis 4,4' diphenyl disocyanate (MDI) , and curing of the mixture. The process of preparing chlorinated rubber polyurethane semi-interpenetrating polymer network composition comprises of following steps. (i) Preparation of Modified Castor Oil Polyethylene Glycol 200 (weight wise 1- 5%), Glycerol (weight wise 6-9%), are mixed with castor oil (weight wise 86-93%) in a container. The mixture is transferred in glass vessel fitted with condenser and mechanical stirrer. The glass vessel is placed over heating mantle/oil bath, maintained at about 160°C and the contents are stirred continuously for about 7 hrs. Intermittent vacuum (3-4 mm of Hg) is applied to remove moisture, if any. The modified castor oil (MCO) thus obtained is estimated for its hydroxyl value using standard technique. The hydroxyl value lies in the range of 265-325. (ii) Mixing of Modified Castor Oil with Chlorinated Rubber Resin Chlorinated rubber resin (5-25 % weight wise) is dissolved in suitable solvents such as xylene, toluene, Methyle isobutyl Ketone etc and the solution is taken in a container. Modified castor oil prepared in above manner (45-60 % weight wise) is added to it with continuous stirring. (iii) Mixing of Methvlene Bis 4.4' Diphenvl Disocvanate (MDI) Methylene bis 4,4' diphenyl disocyanate (MDI) (about 10% over the batch) is added to above solution. The mixture was stirred for 2-3 minutes for homogenous mixing. (iv) Curing of Mixture The homogeneous mixture, prepared in above manner is poured on a glass plate and is allowed to dry at ambient temperature for 24 hrs followed by drying in oven at around 60°C for about 6 hrs. The final product, thus obtained is transparent and flexible in nature. The process of the present invention will now be illustrated with a working example which is intended to be a typical example to illustrate the working of the invention and is not intended to be taken restricti vely to imply any limitation on the scope of the present invention. WORKING EXAMPLE; Polyethylene Glycol 200 (1.6 gm), Glycerol (7 gm), are mixed with castor oil (91.4 gm) in a container. The mixture is transferred in glass vessel fitted with condenser and mechanical stirrer. The glass vessel is placed over heating mantle/oil bath, maintained at about 160°C and the contents are stirred continuously for about 7 hrs. Intermittent vacuum (3-4 mm of Hg) is applied to remove moisture, if any. The modified castor oil (MCO) thus obtained is estimated for its hydroxyl value using standard technique. The hydroxyl value lies in the range of 265-325. Chlorinated rubber resin (24 gm) is dissolved in Methyle isobutyl Ketone (80ml) and the solution is taken in a container. Modified castor oil prepared in above manner (45 gm) is added to it with continuous stirring. Methylene bis 4,4' diphenyl disocyanate (MDI) (31 gm) is added to above solution. The mixture was stirred for 2-3 minutes for homogenous mixing. The homogeneous mixture, prepared in above manner is poured on a glass plate and is allowed to dry at ambient temperature for 24 hrs followed by drying in oven at around 60°C for about 6 hrs. The final product, thus obtained is transparent and flexible in nature. The final film of chlorinated rubber-polyurethane semi interpenetrating polymer network is characterised for damping by employing dynamic mechanical thermal analyser. The film is also characterised for solvent resistant properties utilising standard techniques. There was no swelling of the film in engine oil even after 7 days of exposure. The dynamic mechanical properties for a range of varying compositions of chlorinated rubber (CR) and castor oil based polyurethane (CO-PU) IPNs have been evaluated for the representative composition of example which are tabulated as under:- Composition Dynamic modulus tan max Temp, for Half peak % CR in CO-PU/CR at 65°C(MPa) tan max width (°C) 24 158 0.59 70 33 From the above table it is clear that the proposed IPN composition can be effectively used as damper of mechanical vibrations over a wide range of temperature and frequency. It is to be understood mat the process of present invention is susceptible to adaptations, changes, modifications by those skilled in the art. Such adaptations, changes, modifications are intended to be within the scope of the present invention which is further set forth by following claims. WE CLAIM; 1. A process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition, characterized by the step of: a) mixing modified castor oil with chlorinated rubber resin dissolved in a solvent, wherein 1-5% by weight of Polyethylene glycol 200, 6-9% by weight of glycerol and 86-93% by weight of castor oil is heated at 160°C with continuous stirring for 7 hours under intermimitent vacuum of 3-4 mm of Hg to obtain modified castor oil; b) mixing of methylene Bis 4,4' Diphenyl Disocynate (MDI) to the mixture of modified castor oil and chlorinated rubber resin; and c) curing as herein described of mixture. 2. A process as claimed in claim 1 wherein the hydroxyl value of said modified castor oil is preferably in the range of 265-325. 3. A process as claimed in claim 1 wherein preferably 45-60% by wt. of modified castor oil is mixed with a solution containing 5- 25% of chlorinated rubber resin. 4. A process as claimed in claim 1 wherein the solvent for dissolving chlorinated rubber resin is xylene or toluene or methyl isobrityl ketone. 5. A process as claimed in claim 1 wherein 10% by weight of methylene bis 4,4' diphenyl disocyanate is added with stirring for 2-3 minutes to the said mixture of modified castor oil and chlorinated rubber resin. 6. A process as claimed in claim 7 wherein curing of said mixture is carried out by drying at ambient temperature of 24 hours followed by drying in oven at around 60°C for 6 hours. 7. A process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition substantially as described and illustrated herein.

Full Text

FIELD OF INVENTION
This invention relates to a process for the
preparation of chlorinated rubber-polyurethane semi interpenetrating polymer network composition.
PRIOR ART
A large variety of materials are used to absorb the
mechanical vibrations originating from the machines. These materials are placed between the machine and the floor. These
materials basically comprise of plastic, rubber and paste in the form of film, sheet, block, encapsulating materials etc.
depending upon their use. An improved type of compositions, for absorption of mechanical vibrations, are special rubber blends
prepared through interpenetrating polymer network technique. An interpenetrating polymer network (IPN) composition is a new class
of polymer blend wherein one polymer is synthesised in the immediate presence of other polymer. However, these IPN
compositions used to absorb the mechanical vibrations, known in the art, generally suffer from the following disadvantages.
A primary disadvantage is such known IPN compositions are useful for absorption of mechanical vibrations for a limited
range of temperature only. Another disadvantage is that these compositions are useful only over a narrow range of frequencies
of mechanical vibration. A further disadvantage is that such compositions suffer from high oil swellability thereby adversely
affecting their efficiency over a period of time. A still further disadvantage is that these compositions are capable of
absorbing only limited amount of mechanical energy.

OBJECTS OF THE INVENTION
Primary object of the present invention is to provide a process for preparing chlorinated rubber -polyurethane semi-interpenetrating polymer network (IPN) composition which is based on castor oil.
Another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which absorbs mechanical energy over wide temperature range from 25 to 85 ° C.
Still further object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which has a high damping factor for mechanical vibrations.
Yet another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which works over a wide range of frequencies from 1 Hz to 10 KHz.
Still another object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which has least oil swellability thereby maintaining the stability of the composition over a period of time.
Yet further object of the present invention is to provide a process for preparing chlorinated rubber- polyurethane semi-interpenetrating polymer network composition which can be formed in different shapes such as film, sheet, slab and encapsulant.
Yet another object of the present invention is to provide a process for preparing chlorinated rubber-polyurethane semi-interpenetrating polymer network composition which is cheaper, simple and easy to adopt.
STATEMENT OF INVENTION
According to this invention there is a process for preparation of chlorinated rubber polyurethane semi-interpenetrating polymer network composition, characterized by the step of:
a) mixing modified castor oil with chlorinated rubber resin
dissolved in a solvent, wherein 1-5% by weight of Polyethylene
glycol 200, 6-9% by weight of glycerol and 86-93% by weight of
castor oil is heated at 160°C with continuous stirring for 7
hours under intermimitent vacuum of 3-4 mm of Hg to obtain
modified castor oil;
b) mixing of methylene Bis 4,4' Diphenyl Disocynate (MDI) to the
mixture of modified castor oil and chlorinated rubber resin; and
c) curing as herein described of mixture.
In accordance with the present invention, the process for preparing chlorinated rubber polyurethane semi-interpenetrating polymer
network composition which has high damping factor for mechanical vibrations. The proposed material has high damping factor for the mechanical vibrations pertaining to a wide range of frequencies from I Hz to 10 kHz and is effective over a wide range of operating temperatures from 25 to 85°C. The composition can be formed in different shapes such as film, sheet, slab, encapsulant thereby enhancing its applications. The proposed material has least oil swellability and as such it does not adversely affect the stability of the composition over a period of time. The process is simple and cheaper and easy to adopt. The process comprises the steps of preparation of modified castor oil, mixing of modified castor oil with chlorinated rubber resin, mixing of methylene bis 4,4' diphenyl disocyanate (MDI) , and curing of the mixture.
The process of preparing chlorinated rubber polyurethane semi-interpenetrating polymer network composition comprises of following steps.
(i) Preparation of Modified Castor Oil
Polyethylene Glycol 200 (weight wise 1- 5%), Glycerol (weight wise 6-9%), are mixed with castor oil (weight wise 86-93%) in a container. The mixture is transferred in glass vessel fitted with condenser and mechanical stirrer. The glass vessel is placed over heating mantle/oil bath, maintained at about 160°C and the contents are stirred continuously for about 7 hrs. Intermittent vacuum (3-4 mm of Hg) is applied to remove moisture, if any. The modified castor oil (MCO) thus obtained is estimated for its hydroxyl value using standard technique. The hydroxyl value lies in the range of 265-325.
(ii) Mixing of Modified Castor Oil with Chlorinated Rubber Resin
Chlorinated rubber resin (5-25 % weight wise) is dissolved in suitable solvents such as xylene, toluene, Methyle isobutyl Ketone etc and the solution is taken in a container. Modified castor oil prepared in above manner (45-60 % weight wise) is added to it with continuous stirring.
(iii) Mixing of Methvlene Bis 4.4' Diphenvl Disocvanate (MDI)
Methylene bis 4,4' diphenyl disocyanate (MDI) (about 10% over the batch) is added to above solution. The mixture was stirred for 2-3 minutes for homogenous mixing.
(iv) Curing of Mixture
The homogeneous mixture, prepared in above manner is poured on a glass plate and is allowed to dry at ambient temperature for 24 hrs followed by drying in oven at around 60°C for about 6 hrs. The final product, thus obtained is transparent and flexible in nature.
The process of the present invention will now be illustrated with a working example which is intended to be a typical example to illustrate the working of the invention and is not intended to be taken restricti vely to imply any limitation on the scope of the present invention.
WORKING EXAMPLE;
Polyethylene Glycol 200 (1.6 gm), Glycerol (7 gm), are mixed with castor oil (91.4 gm) in a container. The mixture is transferred in glass vessel fitted with condenser and mechanical stirrer. The glass vessel is placed over heating mantle/oil bath, maintained at about 160°C and the contents are stirred continuously for about 7 hrs. Intermittent vacuum (3-4 mm of Hg) is applied to remove moisture, if any. The modified castor oil (MCO) thus obtained is estimated for its hydroxyl value using standard technique. The hydroxyl value lies in the range of 265-325. Chlorinated rubber resin (24 gm) is dissolved in Methyle isobutyl Ketone (80ml) and the solution is taken in a container. Modified castor oil prepared in above manner (45 gm) is added to it with continuous stirring. Methylene bis 4,4' diphenyl disocyanate (MDI) (31 gm) is added to above solution. The mixture was stirred for 2-3 minutes for homogenous mixing. The homogeneous mixture, prepared in above manner is poured on a glass plate and is allowed to dry at ambient temperature for 24 hrs followed by drying in oven at around 60°C for about 6 hrs. The final product, thus obtained is transparent and flexible in nature. The final film of chlorinated rubber-polyurethane semi interpenetrating polymer network is characterised for damping by employing dynamic mechanical thermal analyser. The film is also characterised for solvent resistant
properties utilising standard techniques. There was no swelling of the film in engine oil even after 7 days of exposure. The dynamic mechanical properties for a range of varying compositions of chlorinated rubber (CR) and castor oil based polyurethane (CO-PU) IPNs have been evaluated for the representative composition of example which are tabulated as under:-
Composition Dynamic modulus tan max Temp, for Half peak
% CR in CO-PU/CR at 65°C(MPa) tan max width (°C)
24 158 0.59 70 33
From the above table it is clear that the proposed IPN composition can be effectively used as damper of mechanical vibrations over a wide range of temperature and frequency.

It is to be understood mat the process of present invention is susceptible to adaptations, changes, modifications by those skilled in the art. Such adaptations, changes, modifications are intended to be within the scope of the present invention which is further set forth by following claims.

WE CLAIM;
1. A process for preparation of chlorinated rubber polyurethane
semi-interpenetrating polymer network composition,
characterized by the step of:
a) mixing modified castor oil with chlorinated rubber resin
dissolved in a solvent, wherein 1-5% by weight of Polyethylene
glycol 200, 6-9% by weight of glycerol and 86-93% by weight of
castor oil is heated at 160°C with continuous stirring for 7
hours under intermimitent vacuum of 3-4 mm of Hg to obtain
modified castor oil;
b) mixing of methylene Bis 4,4' Diphenyl Disocynate (MDI) to the
mixture of modified castor oil and chlorinated rubber resin; and
c) curing as herein described of mixture.
2. A process as claimed in claim 1 wherein the hydroxyl value of
said modified castor oil is preferably in the range of 265-325.
3. A process as claimed in claim 1 wherein preferably 45-60% by
wt. of modified castor oil is mixed with a solution containing 5-
25% of chlorinated rubber resin.
4. A process as claimed in claim 1 wherein the solvent for
dissolving chlorinated rubber resin is xylene or toluene or
methyl isobrityl ketone.
5. A process as claimed in claim 1 wherein 10% by weight of
methylene bis 4,4' diphenyl disocyanate is added with stirring
for 2-3 minutes to the said mixture of modified castor oil and
chlorinated rubber resin.
6. A process as claimed in claim 7 wherein curing of said mixture
is carried out by drying at ambient temperature of 24 hours
followed by drying in oven at around 60°C for 6 hours.
7. A process for preparation of chlorinated rubber polyurethane
semi-interpenetrating polymer network composition
substantially as described and illustrated herein.

Documents:

482-del-2000-abstract.pdf

482-del-2000-claims.pdf

482-del-2000-correspondence-others.pdf

482-del-2000-correspondence-po.pdf

482-del-2000-description (complete).pdf

482-del-2000-form-1.pdf

482-del-2000-form-19.pdf

482-del-2000-form-2.pdf

482-del-2000-gpa.pdf

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Patent Number

222206

Indian Patent Application Number

482/DEL/2000

PG Journal Number

33/2008

Publication Date

15-Aug-2008

Grant Date

28-Jul-2008

Date of Filing

05-May-2000

Name of Patentee

THE CHIEF CONTROLLER, RESEARCH AND DEVELOPMENT

Applicant Address

MINISTRY OF DEFENCE, GOVT OF INDIA, B-341, SENA BHAWAN, DHQ P.O. NEW DELHI-110 011, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	ASIT BARAN SAMUI	NMRL, AMBERNATH (E)- 421506, INDIA.
2	UTTAM GOPAL SURYAVANSHI	NMRL, AMBERNATH (E)- 421506, INDIA.
3	MANORANJAN PATRI	NMRL, AMBERNATH (E)- 421506, INDIA.
4	BIKASH CHANDRA CHAKRABORTY	NMRL, AMBERNATH (E)- 421506, INDIA.
5	PRAMIL CHANDRA DEB	NMRL, AMBERNATH (E)- 421506, INDIA.

PCT International Classification Number

C08L 33/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA