Title of Invention	"AN IMPROVED PROCESS FOR THE PREPARATION OF A POLY PROPYLENE MOULDING COMPOUND HAVING HIGH IMPACT AND HIGH TENSILE STRENTH"
Abstract	This invention relates to an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength. The prior art for the preparation of polypropylene compound having high impact strength consists of either copolymerization or blending with rubbery polymers. The use of modified additives has also been mentioned. However, the process of improving the impact strength almost invariably leads to decrease of tensile strength. Thus there is no prior art for preparation of polypropylene moulding compound having high impact strength as well as high tensile strength. The polypropylene moulding compound prepared according to the process described in the present invention, both the impact strength as well as the tensile strength are higher than that obtained in pure unmodified polypropylene compound.

Title of Invention

"AN IMPROVED PROCESS FOR THE PREPARATION OF A POLY PROPYLENE MOULDING COMPOUND HAVING HIGH IMPACT AND HIGH TENSILE STRENTH"

Abstract

This invention relates to an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength. The prior art for the preparation of polypropylene compound having high impact strength consists of either copolymerization or blending with rubbery polymers. The use of modified additives has also been mentioned. However, the process of improving the impact strength almost invariably leads to decrease of tensile strength. Thus there is no prior art for preparation of polypropylene moulding compound having high impact strength as well as high tensile strength. The polypropylene moulding compound prepared according to the process described in the present invention, both the impact strength as well as the tensile strength are higher than that obtained in pure unmodified polypropylene compound.

Full Text	This invention relates to an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength. There is a large demand for commodity polymers such as polypropylene having enhanced mechanical properties such as tensile and impact strength. The tensile strength of polymers is usually increased by the incorporation of glass fibres. However, this invariably affects the impact strength of polypropylene due to differences in crystallinity and embrittlement at the polymer - fibre interface. Further, glass fibres are very abrasive and cause deterioration of the surface of the barrels and screws of the compounding and moulding machines. It is also difficult to make glass fibre into very thin diameter since it is a high temperature process and special equipment is needed for the same. It is essential to have very thin fibres in order to increase the aspect ratio when added to the polymer especially as short fibres so as to enhance the properties of the final product. The prior art for the preparation of polypropylene compound having high impact strength consists of either copolymerization or blending with rubbery polymers. The use of modified additives has also been mentioned as described in our co-pending patent application \ ...... .._... , - - - — __ (2626/DEL/96). However, the process of improving the impact strength almost invariably leads to decrease o!' tensile strength. Thus there is no prior art for preparation of polypropylene moulding compound having high impact strength as well as high tensile strength. The main object of the present invention therefore is to provide an improved process for the preparation of a polypropylene moulding compound having high impact strength as well as high tensile strength. Accordingly, the present invention provides an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength which comprises; characterized in that complexing a salt of alkaline earth metal with a polymer in an aliphatic alcohol, allowing the complex to digest for 10 to 12 hrs, reacting the digested complex with a solution of sulfate of alkali metal in a polar solvent, allowing it to stand for more than 10 hrs to obtain the precipitate, filtering, washing the precipitate with deionised water and drying at a temperature ranging form 45°C to 55°C to obtain the additive in powder form, mixing the said powdered additive with polypropylene in a ratio of additive to polypropylene in the range of 1:8 to 1:18 (w/w) in a melt extruder to form a homogenous solid, moulding by known methods the above homogeneous solid, to obtain the desired polypropylene molded product having high impact and high tensile strength. In an embodiment of the present invention the non-aqueous solvent used is a aliphatic alcohol selected from methanol, ethanol and butanol. In an embodiment of the present invention the polar solvent used for preparation of the solutions of the sulfates of alkali metal is selected from the group consisting of methanol dimethyl sulfoxide, dimethl foramide and water. In another embodiment of the present invention the polymer used for complexing the reactant contains ether, hydroxyl or carboxylic groups having molecular weight greater than 104 and is selected from the group consisting of polyethylene oxide, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral. In yet another embodiment of the present invention the ratio of additive to polypropylene (w/) used is preferably 1:9. In still another embodiment of the present invention the salt used for complexation is a salt of alkaline earth metal selected from the group consisting of calcium, strontium and barium preferably calcium. In still another embodiment of the present invention the amount of distilled water used for washing the precipitate is ranging from 0.5 to 10 litres, preferably 1 litre for 250 gms of the precipitate formed. The invention is described herein by the following examples, which are illustrative only and should not be construed to limit the scope of the invention in any manner. EXAMPLE - 1 Calcium chloride (163 gms) was dissolved in methanol with continuous stirring while high molecular weight (MW 3 x 105) polyethylene oxide was added to it. The stirring was continued until a clear solution was obtained without any turbidity or particle suspension. This was allowed to stand for 10 hrs at 28°C so as to form a homogenous complex. A solution of potassium sulfate containing 256 gms in 1200 ml methanol was slowly poured in the complex without stirring. The whole mixture v/as allowed to digest for 12 hrs and then stirred for 10 mins and again allowed to stand for 30 mins. The white precipitate obtained was filtered, washed with 3 litres of distilled water, dried to obtain the powder of the additive. 24 gms of this powder were mixed with 200 gms of polypropylene (MFI 8 to 10) in a single screw extruder held at 180°C to 190°C and extruded at I he nozzle temperature of 205°C to obtain strands which were chopped to form pellets of the polypropylene moulding compounds. The modified polypropylene compounded pellets were injection moulded under standard conditions (feed temperature 180°C, mid zone temperature 190°C to 195°C and exit zone at 205°C, mould temperature 26°C and pressure of 1905 bars) to give polypropylene mouldings having high impact and high tensile strength. The properties of these mouldings are given in Table - 1. EXAMPLE - 2 Calcium chloride (205 gms) was dissolved in 1000 ml methanol with continuous stirring to which were added 28 gms of polyethylene oxide (MW 3 x 105). The solution was stirred till the components dissolved completely and then allowed to stand for 10 hrs at 28°C so as to form a complex. Potassium sulfate solution (322 gms in 1200 ml distilled water) was slowly added without stirring to the complex and the mixture digested for 12 hrs at 28°C. The solution was then stirred was for 15 mins and the white precipitate filtered. The precipitate was lightly washed with Table-1 (Table Removed) * Original polypropylene (MFI 8-10) injection moulded under same conditions as in above examples, a , b : Tested as per ASTM standard specifications D 256 and D 638 It is seen from the data in Table-1 that in the polypropylene moulding compound prepared according to the process described in the present invention, both the impact strength as well as the tensile strength are higher than that obtained in pure unmodified polypropylene compound. Thus the process for the preparation of polypropylene moulding compound as described in the present invention leads to improvement of both impact strength and the tensile strength. The main advantage of the present invention is that the additive which is incorporated in polypropylene moulding compound needs no treatment and high impact together with tensile strength are obtained simultaneously with single additive. We Claim: 1. An improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength which comprises; characterized in that complexing a salt of alkaline earth metal with a polymer in an aliphatic alcohol, allowing the complex to digest for 10 to 12 hrs, reacting the digested complex with a solution of sulfate of alkali metal in a polar solvent, allowing it to stand for more than 10 hrs to obtain the precipitate, filtering, washing the precipitate with deionised water and drying at a temperature ranging form 45°C to 55°C to obtain the additive in powder form, mixing the said powdered additive with polypropylene in a ratio of additive to polypropylene in the range of 1 :8 to 1:18 (w/w) in a melt extruder to form a homogenous solid, moulding by known methods the above homogeneous solid to obtain the desired polypropylene molded product having high impact and high tensile strength. 2. An improved process as claimed in claim 1 wherein, the aliphatic alcohol is selected from methanol, ethanol and butanol. 3. An improved process as claimed in claim 1 & 2 wherein, the polar solvent used for preparation of the solutions of the sulfates of alkali metal is selected from the group consisting of methanol dimethyl sulfoxide, dimethyl foramide and water. 4. An improved process as claimed in claim 1-3 wherein, the polymer used for complexing the reactant contains ether, hydroxyl or carboxylic groups having molecular weight greater than 10 and is selected from the group consisting of polythylene oxide, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral. 5. An improved process as claimed in claim 1-4 wherein, the ratio of additive to polypropylene (w/w) used is preferably 1:9. 6. An improved process as claimed in claim 1-5 wherein, the salt used for complexation is a salt of alkaline earth metal selected from the group consisting of calcium, strontium and barium preferably calcium. 7. An improved process as claimed in claim 1-6 wherein, the amount of distilled water used for washing the precipitate is ranging from 0.5 to 10 liters, preferably 1 liter for 250 gms of the precipitate formed. 8. An improved process for the preparation of polypropylene moulding compound having high impact strength and high tensile strength substantially as herein described with reference to the examples.

Full Text

This invention relates to an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength.
There is a large demand for commodity polymers such as polypropylene having enhanced mechanical properties such as tensile and impact strength. The tensile strength of polymers is usually increased by the incorporation of glass fibres. However, this invariably affects the impact strength of polypropylene due to differences in crystallinity and embrittlement at the polymer - fibre interface. Further, glass fibres are very abrasive and cause deterioration of the surface of the barrels and screws of the compounding and moulding machines. It is also difficult to make glass fibre into very thin diameter since it is a high temperature process and special equipment is needed for the same. It is essential to have very thin fibres in order to increase the aspect ratio when added to the polymer especially as short fibres so as to enhance the properties of the final product.
The prior art for the preparation of polypropylene compound having high impact strength
consists of either copolymerization or blending with rubbery polymers. The use of modified
additives has also been mentioned as described in our co-pending patent application
\ ...... .._... , - - - — __
(2626/DEL/96). However, the process of improving the impact strength almost invariably leads to decrease o!' tensile strength. Thus there is no prior art for preparation of polypropylene moulding compound having high impact strength as well as high tensile strength.
The main object of the present invention therefore is to provide an improved process for the preparation of a polypropylene moulding compound having high impact strength as well as

high tensile strength.
Accordingly, the present invention provides an improved process for the preparation of a polypropylene moulding compound having high impact and high tensile strength which comprises; characterized in that complexing a salt of alkaline earth metal with a polymer in an aliphatic alcohol, allowing the complex to digest for 10 to 12 hrs, reacting the digested complex with a solution of sulfate of alkali metal in a polar solvent, allowing it to stand for more than 10 hrs to obtain the precipitate, filtering, washing the precipitate with deionised water and drying at a temperature ranging form 45°C to 55°C to obtain the additive in powder form, mixing the said powdered additive with polypropylene in a ratio of additive to polypropylene in the range of 1:8 to 1:18 (w/w) in a melt extruder to form a homogenous solid, moulding by known methods the above homogeneous solid, to obtain the desired polypropylene molded product having high impact and high tensile strength.
In an embodiment of the present invention the non-aqueous solvent used is a aliphatic alcohol selected from methanol, ethanol and butanol.
In an embodiment of the present invention the polar solvent used for preparation of the solutions of the sulfates of alkali metal is selected from the group consisting of methanol dimethyl sulfoxide, dimethl foramide and water.
In another embodiment of the present invention the polymer used for complexing the reactant contains ether, hydroxyl or carboxylic groups having molecular weight greater than 104 and is selected from the group consisting of polyethylene oxide, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral.
In yet another embodiment of the present invention the ratio of additive to polypropylene (w/) used is preferably 1:9.

In still another embodiment of the present invention the salt used for complexation is a salt of
alkaline earth metal selected from the group consisting of calcium, strontium and barium
preferably calcium.
In still another embodiment of the present invention the amount of distilled water used for
washing the precipitate is ranging from 0.5 to 10 litres, preferably 1 litre for 250 gms of the
precipitate formed.
The invention is described herein by the following examples, which are illustrative only and
should not be construed to limit the scope of the invention in any manner.
EXAMPLE - 1
Calcium chloride (163 gms) was dissolved in methanol with continuous stirring while high
molecular weight (MW 3 x 105) polyethylene oxide was added to it. The stirring was continued until a clear solution was obtained without any turbidity or particle suspension. This was allowed to stand for 10 hrs at 28°C so as to form a homogenous complex. A solution of potassium sulfate containing 256 gms in 1200 ml methanol was slowly poured in the complex without stirring. The whole mixture v/as allowed to digest for 12 hrs and then stirred for 10 mins and again allowed to stand for 30 mins. The white precipitate obtained was filtered, washed with 3 litres of distilled water, dried to obtain the powder of the additive. 24 gms of this powder were mixed with 200 gms of polypropylene (MFI 8 to 10) in a single screw extruder held at 180°C to 190°C and extruded at I he nozzle temperature of 205°C to obtain strands which were chopped to form pellets of the polypropylene moulding compounds. The modified polypropylene compounded pellets were injection moulded under standard conditions (feed temperature 180°C, mid zone temperature 190°C to 195°C and exit zone at 205°C, mould temperature 26°C and pressure of

1905 bars) to give polypropylene mouldings having high impact and high tensile strength. The properties of these mouldings are given in Table - 1.
EXAMPLE - 2
Calcium chloride (205 gms) was dissolved in 1000 ml methanol with continuous stirring to which were added 28 gms of polyethylene oxide (MW 3 x 105). The solution was stirred till the components dissolved completely and then allowed to stand for 10 hrs at 28°C so as to form a complex. Potassium sulfate solution (322 gms in 1200 ml distilled water) was slowly added without stirring to the complex and the mixture digested for 12 hrs at 28°C. The solution was then stirred was for 15 mins and the white precipitate filtered. The precipitate was lightly washed with Table-1
(Table Removed)

* Original polypropylene (MFI 8-10) injection moulded under same conditions as in above examples, a , b : Tested as per ASTM standard specifications D 256 and D 638
It is seen from the data in Table-1 that in the polypropylene moulding compound prepared according to the process described in the present invention, both the impact strength as well as the tensile strength are higher than that obtained in pure unmodified polypropylene compound. Thus the process for the preparation of polypropylene moulding compound as described in the present invention leads to improvement of both impact strength and the tensile strength. The main advantage of the present invention is that the additive which is incorporated in polypropylene moulding compound needs no treatment and high impact together with tensile strength are obtained simultaneously with single additive.

We Claim:
1. An improved process for the preparation of a polypropylene moulding compound having
high impact and high tensile strength which comprises; characterized in that complexing
a salt of alkaline earth metal with a polymer in an aliphatic alcohol, allowing the
complex to digest for 10 to 12 hrs, reacting the digested complex with a solution of
sulfate of alkali metal in a polar solvent, allowing it to stand for more than 10 hrs to
obtain the precipitate, filtering, washing the precipitate with deionised water and drying
at a temperature ranging form 45°C to 55°C to obtain the additive in powder form,
mixing the said powdered additive with polypropylene in a ratio of additive to
polypropylene in the range of 1 :8 to 1:18 (w/w) in a melt extruder to form a homogenous
solid, moulding by known methods the above homogeneous solid to obtain the desired
polypropylene molded product having high impact and high tensile strength.
2. An improved process as claimed in claim 1 wherein, the aliphatic alcohol is selected
from methanol, ethanol and butanol.
3. An improved process as claimed in claim 1 & 2 wherein, the polar solvent used for
preparation of the solutions of the sulfates of alkali metal is selected from the group
consisting of methanol dimethyl sulfoxide, dimethyl foramide and water.
4. An improved process as claimed in claim 1-3 wherein, the polymer used for complexing
the reactant contains ether, hydroxyl or carboxylic groups having molecular weight
greater than 10 and is selected from the group consisting of polythylene oxide,
polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral.
5. An improved process as claimed in claim 1-4 wherein, the ratio of additive to
polypropylene (w/w) used is preferably 1:9.
6. An improved process as claimed in claim 1-5 wherein, the salt used for complexation is a
salt of alkaline earth metal selected from the group consisting of calcium, strontium and
barium preferably calcium.
7. An improved process as claimed in claim 1-6 wherein, the amount of distilled water used
for washing the precipitate is ranging from 0.5 to 10 liters, preferably 1 liter for 250 gms
of the precipitate formed.
8. An improved process for the preparation of polypropylene moulding compound having
high impact strength and high tensile strength substantially as herein described with
reference to the examples.

Documents:

109-del-2001-abstract.pdf

109-del-2001-claims.pdf

109-del-2001-correspondence-others.pdf

109-del-2001-correspondence-po.pdf

109-del-2001-description (complete).pdf

109-del-2001-form-1.pdf

109-del-2001-form-19.pdf

109-del-2001-form-2.pdf

109-del-2001-form-3.pdf

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Patent Number

216973

Indian Patent Application Number

109/DEL/2001

PG Journal Number

13/2008

Publication Date

31-Mar-2008

Grant Date

24-Mar-2008

Date of Filing

31-Jan-2001

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI- 110 001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	SUBRAMANIAM RADHAKRISHNAN	NATIONAL CHEMICAL LABORATORY, PUNE- 411008, (MAHARASHTRA)INDIA
2	COMANDUR SAUJANYA	NATIONAL CHEMICAL LABORATORY, PUNE- 411008, (MAHARASHTRA)INDIA

PCT International Classification Number

C08F 10/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA