This interim report summarizes the development of two modified PET resins, ESPET E-02 and ESPET E-03, for use in toothbrush bristle monofilaments. The resins were designed to have properties closer to PBT, including intrinsic viscosity, melting point, and glass transition temperature. Pilot batches of 10kg and 80kg were produced. Preliminary testing shows the resins have properties within targets. Samples have been sent for outside testing of monofilament production, process feasibility, and bristle-specific tests. A future report will provide a comparative study of the modified PET resins versus PBT.

1. Research project report
on
Development of Specialty PET Grade for
Toothbrush Bristles
(Interim Report)
Prepared By:
Dr. K. Muniswamy Reddy
Prepared By
This document is confidential and is prepared for Plastic Technologies Inc . (USA) by Ester industries Ltd. The contents of
this report represent a research report only, and do not, nor are they intended to provide a legal opinion.

2. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
2
Content
S.No Description Page. No
1 Summary 3
2 Aim of the Product 3
3 Background Art 3
4 Objectives 4
5 List of MajorRaw Materials 4
6 Formulation/Recipe 6
7 Properties 7
8
Comparativestudy of modified
PET with Ultradure B4500
(BASF)
8
9 Process recommendations

3. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
3
1. Summary Points:
We have made twomodifiedPETresinsbyaddingspecificadditivesfortoothbrushmonofilaments. The
productnamesof those tworesinsare ESPET E-02 and ESPET E-03
We findthe intrinsicviscosity, meltingpointandglasstransitiontemperatureof modifiedPETiscloser
to the PBT resin.
We have sentthe resinsforoutside testinglaboratoryformakingfilaments,processfeasibilityand
specifictestsformonofilament.We will givefullcomparative studyreportof modifiedPETwithPBT
(Ultradure B4500-BASF)
2. Aim of the project:
To developnovelpolyethyleneterephthalate co-polymerformanufacturingmonofilamentsfor
toothbrushbristles. AlreadyESTERhasdevelopedamodifiedPET withimprovedmeltflow characteristic
and suppressedcrystallizationrate forinjectionmoldingapplications.WithaSpecialtyPolyestergrade
for bristles,the entire toothbrushcanbe recyclable.
3. Background Art:
Toothbrushbristlesismade extensivelyfromNylon66,Nylon610 and polyesterssuchas
polytrimethyleneterephthalate (PTT) and polybutylene terephthalate (PBT)
The followingpropertiesare essential forToothbrushbristles
 Excellentbendingrecovery/Elasticrecovery/resilience
 Good softness
 Good waterresistant
Nylonisthe preferable polymericmaterialfortoothbrushbristlesdue tohighelasticrecoveryandlow
modulus.Disadvantageof Nylonishighwaterabsorptionandhighcost.
The secondalternate polymerforbristlesispolytrimethylene terephthalate (PTT) itisalsoverygood
elasticrecoveryandlowmodulus.The majordisadvantageof thispolymerispoorprocessabilityof the
filamentdue toshrinkage duringheatshrinkage.Itcreatessomanybreaksinfilament.

4. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
4
The presentmostusedtoothbrushbristlesare polybutylene terephthalate (PBT).ItissimilartoNylon
properties,comparativelylowcost. Waterabsorptionisalmost
Generally PETis not suitableforuse in formingtoothbrushbristlesdue to poor bendingrecovery, too
highmodulus(bristlesare too stiff).However PET hassuperior mechanical properties& excellent
recyclability.
4. Objectives:
The presentobjective of thisdevelopmentis tomodifythe PETto similarpropertiesof monofilamentsis
closerto PBT.For monofilamentapplications,itisnotnecessarytomatch crystallizationrate.Butitis
betterto modify
1. Resiliency.
2. To improve the flexibilityof backbone TOIMPARTSOFTNESSof the Polymer.
3. To reduce meltingtemperature &improve meltflow characteristicof the Polymer.
5. List of Major Raw materialsused:
We have usedthe followinglistof rawmaterialsforthe new productdevelopment
1. Purifiedterephthalicacid:It is a extensivelyused dicarboxylicacid forPET resinsynthesis.Itcan
be usedabout 95 mole weightpercentinformulation
2. IsophthalicAcid: It is well know diacidco-monomerforCo-PETsynthesis.Itwill usedtoreduce
crystallinity, glasstransitiontemperature andmeltingpointbyincreasingmole weightpercent.
It can alsoprovide verygood colorfor the resin
3. Ethylene Glycol:EG is the mail diol componentinPETresinitwill be addedabout95 mole
weightpercentage inco-polyesterresin
4. Other Additive:Special additiveswere addedtobringimprovedresiliency&softnessin
polymer.
 The criterionforselection of additives:
 Servesintendedpurpose

5. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
5
 Harmlessforreactionkinetics
 Thermallystable upto290 °C
 Shouldnotaffectpolymercolor
 Should notadverselyaffectfilterability
6. Formulations:
For developingnovel polyethylene terephthalate polymerformonofilaments,we have designed mainly
for three experiments. Firsttwoexperimentsare conductedinpilotplantfor10 kg. Afterstudyingall
experimentproperties andprocessfeasibilities we have carriedoutthirdexperimentin80 kg pilotplant
and considered asafinal formulationformonofilamentdevelopment.
Formulation:
a) Recipe for 10 kg pilotplant (p-01)
S.No Raw Material ESPET E-02 ESPET E-03
1 PTA 6.601 6.601
3 EG 2.841 2.841
4 AR-04 0.539 0.539
5 Catalyst (Sb2O3) 0.003 0.003
6 Cobalt acetate 0.002 0.002
7 Ortho Phosphoric Acid 0.001 0.001
8 Blue toner 0.00025 0.00025
9 AR-01 0.013
10 AR-02 0.013

6. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
6
b) Recipe for 80kg pilotplant (P-02)
ESPET-02 and ESPET-03 samples were synthesized in 80 kg pilot plant. The main difference in both
formulationsisadditivesonly.
For preparation of modified PET, 52.81kg of PTA and 22.73 kg of MEG were made into a paste and fed to
the Esterification reactor. PTA:MEG mole ratio of 1:1.07 and 4.31 kg of AR-04 were taken in the
Esterification reactor. 24 g of antimony trioxide catalyst, 17 g of Cobalt Acetate and 11 g of ortho-
phosphoric acid were added to the esterification reactor . Esterification was carried out between 240
and 260° C. After the completion of esterification 100g of AR-01 additive is added to the esterifier. The
prepolymer with all the additives was transferred via a 20 micron filter to the polycondensation reactor.
Polymerization was conducted between 270 and 285° C. with a peak temperature of 288° C. to achieve
the required I.V. in the melt. After reaching the required I.V. the amorphous co polyester resin melt was
extruded out as strands and cut under water and collected as amorphous chips. These amorphous chips
were dried and pre-crystallized before subjecting to solid state polymerization (SSP) for increasing the
I.V.
S.No Raw Material ESPET E-02 ESPET E-03
1 PTA 52.81 52.81
3 EG 22.73 22.73
4 AR-04 4.31 4.31
5 Catalyst (Sb2O3) 0.024 0.024
6 Cobalt acetate 0.017 0.017
7 Ortho Phosphoric Acid 0.011 0.011
8 Blue toner 0.002 0.002
9 AR-01 0.10
10 AR-02 0.10

7. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
7
Similarlyinthe secondsetadditive AR-02wasaddedinsteadof additiveAR-01
We have selectedthe twomostoptimum formulationsforthe manufacturingof monofilamentdue toit
isprovidingoptimumpropertiesandcomparable tothe polybutyleneterephthalate (PBT).
The intrinsicviscosity ismeasuredata temperature of 25° C. at 0.5 g/dL concentrationina solvent
mixture of symmetrictetrachloroethane andphenolhavingaweightratioof symmetric
tetrachloroethanetophenol of 2:3.
The 2nd cycle glasstransitiontemperatures,meltingpointand% of crystallinity weredetermined
accordingto DSC at a heatingrate of 10° C./minto a temperature of 300° C.,
7. Properties
The propertiesof amorphousandSSPchipsof modifiedCo-PETare giveninthe below tables.
(A) Meltpolymerized amorphous chipsproperties.
S.N Parameter Unit ESPET E-02 ESPET E-03
1 Intrinsic Viscosity dl / gm 0.620+0.02 0.620+0.02
2 Carboxylic End group
meq /
Kg
Max 40 Max 40
3 Ash Content wt% ≤0.030 <=0.030
4 Color Value (CIE Scale )
L* value %
b* Value - 5+2 5+2
6
Melting temperature
(Tm2)
℃ 230+3 230+3
7 Chips/gm No. 35+5 35+5
8 Bulk Density Gm/cc 800+50 800+50
9 PET Fines ppm Max 100 Max 100
10 Moisture when packed wt % ≤0.02 ≤0.02

8. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
8
(B) SSPchipsproperties:
The solidstate polymerizationprocessisusedtoimprove the molecularweight(IntrinsicViscosity)
of amorphouschips. Inthisprocessamorphouschipswere loadedintremblerdriertocrystallizethe
chipsto avoidstrikingoragglomerationof chipsthenaftercrystallizationthe same chipswere
undergone SSP process.The propertiesof SSPchipsare listedinthe below table
S.N Parameter Unit ESPET E-02 ESPET E-03
1 Intrinsic Viscosity dl / gm 0.820+0.02 0.820+0.02
2 Carboxylic End group meq / Kg Max 30 Max 30
3 Ash Content wt% ≤0.030 <=0.030
4 Color Value (CIE Scale )
L* value %
b* Value - 5+2 5+2
6
Melting temperature
(Tm2)
℃ 230+3 230+3
7 Chips/gm No. 35+5 35+5
8 Bulk Density Gm/cc 800+50 800+50
9 PET Fines ppm Max 100 Max 100
10 Moisture when packed wt % ≤0.02 ≤0.02

9. Khatima
Development of Specialty PET Grade for
Toothbrush Bristles
Project N0: ES-01/12
Plastic TechnologyInc.
9
8. Comparative studyof modifiedPETwithUltradure B4500 (BASF)
We have sentthe samplestoexternal testinglaboratorytomake filamentsandconduct all test
relatedtobristles.We will provide youacomparative studyreportof modifiedPETwithUltradure
B4500 (BASFproductwhichisusedfor toothbrushbristles) within2weeks
S.N Parameter Unit ESPET E-02 ESPET E-03
Ultadure
B4500
1 Intrinsic Viscosity dl / gm
2 Carboxylic End group meq / Kg
3 Density g/cm3
4 Tensile strength Gpa
5 Elongation at break %
6 Initial Modilus cN/dtex
7
Melting temperature
(Tm2)
℃
8
Water absorption for 24
hours
%
9 Bend recovery %
10
Dimensional Stability in
Wet and Dry conditions
(%)
%
9. Recommendedguidelinesforprocessof the polymer
1) Drying: The sample driedat150°C for 5 hourshumidity
2) Extrusionandspinning:Meltingtemperatureat280 °C