FORM 2 THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
A POLYMER ADDITIVE COMPOSITION
FINE ORGANIC INDUSTRIES LTD
A company incorporated under the laws of India having their office at Fine House, Anandji Street, Ghatkopar East, Mumbai - 400 077
The following specification particularly describes the invention and the manner in which it is to be performed

A POLYMER ADDITIVE COMPOSITION
The present invention relates to a polymer additive composition based on dicarboxylic acid and dicarboxylic acid monoester of polyhydric alcohol, its preparation and use in polymers to improve barrier properties.
BACKGROUND OF THE INVENTION
The following publications suggest polymer modifications to improve barrier
properties -
European patent EP0645417B1 teaches biaxially oriented polypropylene film
with improved water vapor barrier properties.
European patent EP0341188B1suggests specific method of extrusion of films to
improve barrier properties.
European patent EP0441027B1 teaches modified polyolefin film with improved
barrier properties.
The above options for improving barrier properties of polymers employ complex technologies which entail high costs.
United States Patent application US20190159446A1 (referred to herein as the '446 publication) teaches use of monocarboxylic acid and dicarboxylic acid monoesters as film enhancing component in forming an exogenous flexible film on a plant to enhance the shelf-life of the plant. The exogenous flexible film is found to be successful in both preserving the plants from stressful conditions such as insects, microbes, moisture and/or weather and providing additional protection to the plant.
The monocarboxylic acid and dicarboxylic acid monoesters suggested in '446 are isopropyl palmitate, isopropyl stearate, butyl stearate, diisopropyl adipate, dibutyl

adipate, dioctyl adipate, glyceryl adipate, myristylmyristate, polyglyceryl oleate, polyglyceryl laurate, polyglyceryl stearate, polyglyceryl palmitate and the like.
The film enhancing component is defined as molecules that may be utilized to enhance film spreading and/or to increase stability of solutions that are utilized to form exogenous flexible films. There is no suggestion that the dicarboxylic acid monoesters improve the barrier functions of the films leading to decrease in the Water Vapor Transmission Rate (WVTR) of the exogenous flexible films. The decrease in the WVTR leads to improving shelf-life of the packaged products. Further, there is no suggestion of use of the film enhancing component in polymeric packaging articles such as films used to improve the shelf-life of cooked food & use in food and non-food solid and liquid containers.
PCT publication W01999/25751A1 (referred to herein as the '751 publication)
suggests use of additives containing carbonic acid esters and/or carboxylic acid
ester groups of the general formula

wherein R1, R2, R3, R4, R5 are hydrogen or alky I; and 0 0 and 1 < n < 104
into various polymers as a simple solution to achieve an improvement in the barrier and processing properties of the polymers.

OBJECT OF THE INVENTION
The object of the present invention is to provide a polymer additive composition of dicarboxylic acid and dicarboxylic acid monoester of polyhydric alcohol, its preparation and use in polymers to improve barrier properties against gases, water vapor and aromas.
SUMMARY OF THE INVENTION
A polymer additive composition comprising.
(a) dicarboxylic acid; and
(b) dicarboxylic acid monoester of polyhydric alcohol. A polymer additive composition comprising

(a) adipic acid in 50 to 90% weight by total weight of the composition;
(b) adipic acid monoester of glycerol in 10 to 50% weight by total weight of the composition; and
(c) one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers and nucleating agents.
DESCRIPTION OF THE INVENTION
A variety of plastic packaging materials such as films are used in packaging applications such as bags, pouches, tubes, trays, bubble packs, layers with metal foil or cellulosic material such as paper. These films need to possess good physical and mechanical properties along with improved barrier properties.

Films with improved barrier properties are particularly important for packaging of goods in the food, pharmaceutical and/or electronic industry. It is desirable to retain high moisture levels within the package or prevent moisture ingression across the film barrier. Films having low water vapor transmission (WVTR) rates will be useful in food packaging to prevent dehydration of the packaged food or prevent rehydration of dried packaged food.
Polymer additives are added based on the end use requirement of the polymer. For e.g. if the end use is in engineering plastics, impact would be a major concern and choice of an impact modifier is critical or if the end use is in packaging materials like films then the color dispersants, lustrous look or providing a barrier to water ingression would be crucial.
The present invention is to a polymer additive composition for packaging materials like films which protects the contents stored in the film from water ingression.
According to the first embodiment of the present invention is a polymer additive composition comprising dicarboxylic acid and dicarboxylic acid monoester of polyhydric alcohol.
More specifically, the polymer additive composition provides improved barrier properties to polymeric packaging materials. The polymer additive composition of the present invention helps in preventing water ingression into the packaged material leading to a longer shelf-life of the packaged material.
According to the second embodiment of the present invention is a polymer additive composition comprising
(a) adipic acid in 50 to 90% weight by total weight of the composition;

(b) adipic acid monoester of glycerol in 10 to 50% weight by total weight of the composition; and
(c) one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers nucleating agents and plasticizers.
The dicarboxylic acid in the polymer additive composition of the present invention may be selected from succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid. Preferably adipic acid.
The dicarboxylic acid may be in 50 to 90% weight by total weight of the composition.
The polyhydric alcohol may be selected from ethylene glycol, propylene glycol and glycerol.
The dicarboxylic acid monoester of polyhydric alcohol may be in 10 to 50% weight by total weight of the composition.
The dicarboxylic acid monoester of polyhydric alcohol may be selected from ethylene glycol monoester of succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid. The dicarboxylic acid monoester of polyhydric alcohol may be selected from propylene glycol monoester of succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid. The dicarboxylic acid monoester of polyhydric alcohol may be selected from glycerol monoester of succinic acid, glutaric acid, adipic acid, azelaic acid and sebacic acid.

The polymer may be selected from polyvinylchloride, polyethylene and polypropylene. The polymer is used in polymeric packaging articles selected from films, food and non-food solid and liquid containers.
The polymer additive composition may comprise one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers, nucleating agents and plasticizers.
The antioxidants may be selected from n-acetyl cysteine, cysteine, salts of cysteine, sodium salts of cysteine, potassium salts of cysteine, calcium salts of cysteine, ethyl gallate, propyl gallate, cetyl gallate, dodecyl gallate, ascorbic acid, sodium salts of ascorbic acid, potassium salts of ascorbic acid, calcium salts of ascorbic acid, ascorbyl palmitate and/or ethyl maltol. The antioxidant may be in 0.01 to 1% weight by total weight of the composition.
The antistatic agents may be selected from fatty acid esters, ethoxylated alkylamines, ethoxylated alcohols, complex esters or from other classes including anionic, cationic or amphoteric antistatic additives can be used in specific combinations of two or more in order to attain desired function in the base PVC formulations.
The stabilizers may be selected from lead based - several lead salts, lead soaps -lead stearate; barium-cadmium (Ba/Cd) soaps include laurates, stearates and myristates, mixed/co-precipitated/other forms or combinations with organic salts, barium-cadmium-zinc (Ba/Cd/Zn) along with synergistic stabilizer; tin stabilizer -organotin based compounds including derivatives for instance methyl, octyl, butyl and more; various organic salts of calcium, magnesium and zinc in combination with epoxy compounds.

The antibacterial agents may be selected from methyl parabens, propyl parabens, ethyl alcohol, isopropyl alcohol, proxel-type BIT biocides, and/or calcium propionate sodium acetate, acetic acid, calcium acetate, sodium benzoate, benzoic acid, potassium, sodium sorbate, potassium sorbate, sorbic acid, vanillin, ethylvanillin, propanoic acid, sodium propanoic acid salt, calcium propanoic acid salt, ascorbyl palmitate, methyl-p-hydroxy-benzoate, methyl parabens sodium salt, propyl-p-hydroxy benzoate, propyl parabens sodium salt, butanol, ethanol, phenol, propyl gallate, benzyl alcohol, phenoxy ethanol, ethyl-p-hydroxybenzoate, butyl-p-hydroxybenzoate, phenoxy ethanol, ethyl propionate, ethyl butyrate, p-chloro-m-xylenol, vitamin E, a-tocopherol, butylated hydroxyl-anisole (BHA), butylated hydroxyl-toluene (BHT), imidazolidinyl urea, diazolidinyl urea, sodium salts of ethylenediamine-tetraacetate, potassium salts of ethylenediamine-tetraacetate, 1,2-benzisothiazolin-3-one, cetyl pyridinium chloride, phenethyl alcohol, potassium lactate, sodium lactate, quaterium 14, quaterium 15, quaterium 24, benzalkonium chloride, benzathonium chloride, dilauryl thiodipropionate, dicetyl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, ditridecyle thiodipropionate, phosphatidylcholine, diisopropyl cresol, chlorobutanol, myristalkonium chloride, stearalkonium, tea tree oil, thyme oil, chloroxylenol, isopropanol, benzoic acid ammonium salt, benzoic acid calcium salt, benzoic acid magnesium salt, benzoic acid potassium salt, benzoic acid sodium salt and/or potassium acetate.
The antibacterial agent may be selected from fatty acid monoester of glycerol; wherein the fatty acid is selected from C8 to C14 fatty acids. The antibacterial agent may be in 0.01 to 1% weight by total weight of the composition.
The lubricants may be selected from paraffins, paraffinic oil, fatty acids, waxes based on polyethylene, fatty acid amides/esters/alcohols and metal soaps; can be

used in specific combinations of two or more in order to attain desired lubrication in the base PVC formulations.
The plasticizers may be selected from glycerin, polysorbate 20, a plant extract, yucca extract, propylene glycol, sorbitol, sorbitol solutions, sorbitan monostearate, sorbitan monooleate, lactamide, acetamide DEA, lactic acid, polysorbate 60, polysorbate 80, polyoxyethylene-fatty acid esters, triacetin, dibutyl sebacate, polyglyceryl-fatty acids, and/or polyoxyethylene-fatty acid esters. Other examples of plasticizing component 56 include poly glycerol oleate, poly glyceryl 10 oleate, poly glyceryl 4 oleate, poly glyceryl 5 oleate, poly glyceryl 6 oleate, poly glyceryl 8 oleate, poly glyceryl stearate, poly glyceryl 6 stearate, poly glyceryl 2 stearate, poly glyceryl 4 stearate, lactic acid ethyl ester, and/or lactic acid n-butyl ester. The plasticizer may be in 1 to 2wt% dosage level that is suitable for the achieving required end properties by total weight of the composition.
The polymer additive composition of the present invention may be used in polymeric packaging articles selected from films, food and non-food solid and liquid containers. The polymer additive composition of the present invention provides a lower water vapor transmission rate (WVTR) acting as a barrier additive in polymeric packaging articles.
The polymer additive composition of the present invention prevents water from entering into the packaged materials enhancing the shelf-life of the packaged material.
WVTR is defined as water vapor transmission rate and is measured using the Water Vapor Transmission Rate method no. ASTM F 1249 in order to determine the WVTR values for plastic films and sheets.

This is tested using the Water Vapor Transmission Rate method with the specific test parameters.
Specific test parameters for WVTR:
Test temperature: 38±0.5 deg C Test relative humidity: 90±3 % RH Conditioning: 1 hour Test area: 50 cm2
Lower WVTR value is an indication of lesser amount of water vapours passing through the plastic film/sheets/specimen. This is desirable for applications sensitive to moisture such as packaging.
The polymer additive composition of the present invention may be mixed with polymeric resin and one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers and nucleating agents; during melt compounding processes known in the state of the art.
The following examples illustrate preferred embodiments in accordance with the present invention without limiting the scope of the invention.

EXAMPLES
Example 1: Preparation of Glycerol Adipate
Raw Materials:

Sr. No. Chemicals Quantity (g)
1 Glycerol 138 (1.5 mole)
2 Adipic Acid 219 (1.5 mole)
3 Hypophosphorous acid (Catalyst) 0.657 (0.3% Adipic acid)
4 Nitrogen Gas As per requirement
Procedure:
1. Clean and dry all the glassware's/ equipment required for the batch.
2. Charge the required quantity of Glycerol to the reactor through the additional funnel.
3. Start the heating to the Glycerol under constant stirring and nitrogen gas bubbling.
4. Maintain the temperature of the Glycerol to the 90°C.
5. At this temperature, Start the slowly addition of the Adipic Acid to the Glycerol through the additional funnel. Addition time is should be about 15 min.
6. After complete addition of Adipic acid, add the required quantity of VPA catalyst at 90°C under nitrogen bubbling.
7. Raise the temperature of the reaction mixture to 150°C.
8. Allow to pass the steam vapor to pass through the vent. Observe the progress of the reaction from the steam evolution (Byproduct: Water formation).
9. Maintain the temperature of the reaction mixture to 150°C for 90 minutes.
10. Increase the temperature of the reaction mixture to 180°C.
11. Maintain the reaction mixture to 175-180°C under constant stirring and nitrogen bubbling.
12. During maintaining the reaction, check the acid value of the reaction mixture after 1 Hr.
13. After 1 Hr. maintaining, check the sample for acid value after every 30 minutes.
14. Acid value limit- 70 mg KOH/g.
15. If the acid value is in limit cool the batch to 120°C under nitrogen pressure and transfer the product to the storage.

16. If the acid value is not in limit then continue the batch till acid value limit meets. Yield: 297 g- 0.832 X (Theoretical- 310 g)

Sr. No. Test Barrier Agent
1 Appearance Glassy viscous mass
2 Acid Value 68.05
3 Sap Value 525.43
4 Hydroxyl Value 347:8
Example 2: Polymer additive composition of the present invention Raw Materials:

Sr. No. Chemicals Quantity (g) Specifications and Source
1 Glycerol Adipate 270 Example 1
2 Adipic Acid 450 Acid Value: 767,
Procedure:
1. Clean and dry all the glassware's/ equipments required for the batch.
2. Charge the required quantity of Glycerol Adipate to the reactor.
3. Start the heating to the Glycerol Adipate under constant stirring.
4. Maintain the temperature of the Glycerol Adipate to the 120°C.
5. At this temperature, Start the slowly addition of the Adipic Acid to the Glycerol Adipate. Addition time is should be about 15 min.
6. Maintain the temperature to 120-125°C under constant stirring. At this temperature reaction mixture will become homogeneous and clear.
7. Continue the mixing till the reaction mixture becomes homogeneous and clear.
8. Transfer the product to the storage.
9. Analyze the reaction product for Acid value, Sap value and Hydroxyl value.
Results:

Sr. No. Test Barrier Agent
1 Appearance White pasty mass
2 Acid Value 487.82
3 Sap Value 677.6
4 Hydroxyl Value 134.26

Example 3 Use of polymer additive composition of Example 2 in PVC

Material Quantity in phr
PVC resin (K 67) 100
Methyl tin stabilizer 1.5
ESBO (Plasticizer) 1.5
Internal lubricant 0.8
External lubricant 0.3
Release agent 0.2
Processing aid (Acrylic based) 1.5
Impact modifier (Acrylic based) 4.0
Polymer Additive composition of Example 2 1-2
Dry blend preparation:
Dry blends were prepared using laboratory scale high speed mixer of 10 L capacity.
Material charge sequence:
■ PVC resin, stabilizer and secondary plasticizer were mixed until the mixture temperature reached 50 to 60 deg C.
■ Processing aid and impact modifier were added followed by mixing to temperature 75 to 80 deg C.
■ Further, the specialty lubricants were incorporated along with Finalux BA to mix up to temperature 100 to 110 deg C.
■ The dry blend was discharged & cooled to room temperature.
Film Blowing:
Film was blown (thickness: approx. 500 microns) using laboratory scale single
screw extruder.
Temperature profile:
180,195, 210,195 & 200 deg C on an extruder

Performance evaluation:
Film samples prepared in the lab were evaluated for the Water Vapor Transmission Rate (WVTR) at an external third-party test lab as per ASTM F-1249 standard.
Experimental:
ASTM F 1249 test method determines the water vapor transmission rate (WVTR) through a plastic film or sheet.
Control PVC sample and PVC sample containing polymer additive composition of Example 2 were tested with the mentioned standard in order to determine WVTR in g/(m2.day).
Specific test parameters:
Test temperature: 38±0.5 deg C Test relative humidity: 90±3 % RH Conditioning: 1 hour Test area: 50 cm2

Test Parameters Comparative study
PVC-Control without additive Polymer additive
composition of
Example 2
@ 1 phr Gycerol adipate
of Example 1 @
1 phr Adipic acid 1 @1 phr
WVTR Test (g/m2.day) 1.241 0.845 0.891 0.931
Results and discussion:
WVTR value decreased in the presence of Polymer additive composition of Example 2 (@1 phr) compared to the PVC control film without additive.

WE CLAIM
1. A polymer additive composition comprising
(c) dicarboxylic acid; and
(d) dicarboxylic acid monoester of polyhydric alcohol.

2. The composition as claimed in claim 1 wherein the dicarboxylic acid is selected from succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and combinations thereof.
3. The composition as claimed in claim 1 wherein the dicarboxylic acid is in 50 to 90% weight by total weight of the composition.
4. The composition as claimed in claim 1 wherein the polyhydric alcohol is selected from ethylene glycol, propylene glycol, glycerol and combinations thereof.
5. The composition as claimed in claim 1 wherein the dicarboxylic acid monoester of polyhydric alcohol is in 10 to 50% weight by total weight of the composition.
6. The composition as claimed in claim 1 wherein the polymer is selected from polyvinylchloride, polyethylene and polypropylene.
7. The composition as claimed in claim 6 wherein the polymer is used in polymeric packaging articles.

8. The composition as claimed in claim 7 wherein the polymeric packaging articles are selected from films, food and non-food solid and liquid containers.
9. The composition as claimed in claim 1 further comprising one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers and nucleating agents.
10. The composition as claimed in claim 9 comprising antibacterial agent selected from fatty acid monoester of glycerol; wherein the fatty acid is selected from C8 to C14 fatty acids and combinations thereof.
11. The composition as claimed in claim 10 wherein the antibacterial agent is in 0.01 to 1% weight by total weight of the composition.
12. A polymer additive composition comprising

(d) adipic acid in 50 to 90% weight by total weight of the composition;
(e) adipic acid monoester of glycerol in 10 to 50% weight by total weight of the composition; and
(f) one or more excipients selected from antioxidants, antistatic agents, stabilizers, flame retardants, antibacterial agents, lubricants, flow improvers and nucleating agents.

13. The composition as claimed in claim 12 comprising
(a) adipic acid in 50 to 90% weight by total weight of the composition;
(b) adipic acid monoester of glycerol in 10 to 50% weight by total weight of the composition; and
(c) an antibacterial agent selected from a fatty acid monoester of glycerol; and
wherein the fatty acid is selected from C8 to C14 fatty acids and antibacterial
agent is in 0.01 to 1% weight by total weight of the composition.