FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2016
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
1. Title of the Invention:-
“COMPOSITIONS FOR CONTROL AND INHIBITION OF
POLYMERIZATION OF VINYL AROMATIC MONOMERS, AND METHODS OF USE THEREOF”
2. Applicant(s):-
Name : DORF KETAL CHEMICALS (INDIA) PRIVATE LIMITED
Nationality : A Company organized under the Laws of India
Address : Dorf Ketal Tower, D’Monte Street, Orlem, Malad (W), MUMBAI
400064, Maharashtra, INDIA
3. Preamble to the Description:-
Complete Specification:
The following specification particularly describes the Invention and the manner in which it is to be performed.

Title of the in\ention:
Compositions for Control and Inhibition of Polymerization of Vinyl Aromatic Monomers, and Methods of Use thereof.
Field of the invention:
The present invention relates to compositions for control and inhibition of polymerization of vinyl aromatic monomers, and methods of use thereof, wherein aromatic vinyl monomer includes stvrene. wherein improvement comprises a composition of at least one amine wilh mixture of one or more quinone mclhide or derivative thereof and one or more phenolic compound.
In one embodiment. the present invention relates l. and/or tris|N-butylaminc) i.TBA) is added to a composition comprising a combination of QM and phenolic compounds. then, polymerization controlling and inhibiting efficiency of the prior art composition comprising a combination of QM and phenolic compounds is not improved. Therefore. Ihe compositions comprising triethanolamine (TEA), monoclhanolaminc (MEA). diethanolaminc iDEA). and/or tris|N hutylaminc| iTBA) with a combination of QM and phenolic compounds are not in accordance with the present invention.
Wordingly. the present invention relates to an improved amine based additive composition for controlling and inhibiting polymerization of aromatic vinyl monomers including styrene comprising:
(A i one or more quinone melhide or derivatives thereof (QM).
(B) one or more phenolic compounds, and
characterized in that the said composition further comprises:
(O al least one amine comprising aliphatic tertiary amine containing OH group in the alkyl chain.
In accordance with one of the embodiments of the present invention, the amine of the present invention makes the present composition economical as well as environment friendly.
In accordance with the most preferred embodiment of the present invention, the aliphatic tertiary amine containing hydroxy] group in the alkyl chain comprises iri-isopropanol amine ortris<2-hydroxypropyhaminc (TIPA).
In accordance with one of the embodiments of the present invention. Ihe aliphatic tertiary amine containing hydroxyl group in the alkyl chain may comprise N.N.N'.N'-Tetrakis {2-hydroxyethvlt ethylene-diamine (THEED). N.N.N '.N -Tetrakis

(2-hydroxypropyli ethylene-diamine (Quadrol"'). or a mixture thereof. However, as
described herein above, ilie compositions comprising N.N.N'.N* tetrakis <2-
hydro\\piopy|> elhylenediamine (Quadrof*). 2.2'.2".2'"-( 12-
LtlnincdivldmiiriloHctraethanol (THEED). or a mixture thereof with a combination of QM and phenolic compounds are the second preferred embodiment of the present invention.
Therefore, in first embodiment, the present invention relates to an improved amine based additive composition for control and inhibition of polxmcri/alion of aromatic vinyl monomers including styrene comprising:
(A) one or more quinone melhide or derivatives thereof (QM).
(B i one or more phenolic compounds, and
characterized in that the said composition further comprises:
(O at least one amine comprising aliphatic tertiary amine containing -OH group in the alkyl chain.
wherein said aliphatic tertiary amine comprises tri-isopropanol amine iTIPA).
Therefore, in accordance wiUi another embodiment of the present invention it relates to the additive composition, wherein the aliphatic tertiary amine containing hydroxy! group in the alkyl chain comprises N.N.N'.N-Tetrakis <2 hydroxyethyl) ethylene-diamine (THEED). N.N.N'.N'-Tetrakis (2 hydroxv propyl* ethylene-diamine (OuadroTv). or mixture thereof.
Therefore, in second embodiment, die present invention relates to an improved amine based additive composition lor control and inhibition of polymerization of aromatic vinyl monomers including styrene comprising:
(A) one or more quinone mcthide or deriv ati\vs thereof (QM).
(UI one or more phenolic compounds, and
characleri/ed in that the said composition further comprises:
(C) .ii least one amine comprising aliphatic tertiary amine containing -OH group in the alkyl chain.
wherein said aliphatic tertiary amine is selected from the group comprising:
i) tns(2-hydroxypropyl)amine (TIPA):
ii) and may additionally comprise N.N.N'.N-Tetrakis i2-hydroxypropyl) ethylene-diamine (Qnadft
iii) N.N.N'.N'Tetrakis (2-hydroxycthyl) ethylene-diamine (THEED): and
i\ i a mixture thereof.

The inventor has found thai when composition of the present invention comprises at least one of the aliphatic tertiary amine of the present invention, the efficiency of QM and phenolic compounds to control and inhibit polymerization of aromatic vinyl monomers including stytene is. surprisingly and unexpectedly. substantially improved to the an improved level that's too at substantially reduced <>i minimized dosages of QM and phenolic compounds, thereby making the composition of present invention relatively more economical and environment friendly.
In accordance with one of the embodiments of the present invention, the phenolic compound comprises 2.6-di-lert-bulyl phenol (2.6 DTBPL butylated hydroxy anisole (BHA). butylated hydroxy toluene (BUT), or a mixture thereof.
In accordance with one of the embodiments of the present invention, the phenolic compound does not comprise hydroquinonc (HQ>. particularly it docs not comprise 1.4-hcn/cne diol or 1.4-dihydroxy ben/ene. because the inventor has found that when the phenolic compound is MQ and is in combination with the QM. then surprisingly and unexpectedly, the addition of the aliphatic tertiary amine of the present invention doei not improve the polymerization controlling and inhibition efficiency with reduced amount of the QM and IIQ.
In accordance with one of the embodiments of the present invention, the said quinonc meUiidc or derivatives thereof (QM) comprises benzyl quinone memide. preferably 4-ben/ylidenc.2.6-di-iert-bulyl cyclohexa-2.5-dienone.
It may be noted that said quinone methide or derivatives thereof herein after may be referred to as QM.
In accordance with one of the embodiments of the present invention, in the mixture Of QM and phenolic compound, the QM may be taken in an amount varying lumi about 0.2 to about 99.8 % by wl. and the phenolic compound may be taken in an amount varying from about 99.8 to about 0.2 (A by wt. of the mixture of the QM and the phenolic compound.
In accordance with one ot the embodiments of the present invention, the mixture of the QM and the phenolic compound may comprise the QM and the phenolic compound in a weight ratio varying from about 99.8:0.2 to about 0.2:99.8.
In accordance with one of the embodiments of the present invention, the said aliphatic tertiary amine or mixture thereof is taken an amount varying from about 0.01 to about 70 9S by wt. of the composition, preferably varying from about 0.1 to about 50 % by wl. of the composition, more preferably varying from about 0.5 to about 30 ck by

wt. of the composition, even more preferably varying from about 1 to about 20 % by \vt. of the composition.
It may be noted that the stream comprising aromatic vinyl monomers including styrcne may be referred to as monomer stream or as aromatic vinyl monomers stream.
In accordance with one of the preferred embodiments of the present invention, the composition of present invention may be added to the stream containing aromaiic vinyl monomers including styrene in an amount varying from about 0.01 ppm to about 5 ppm, preferably varying from about 0.1 ppm to about 3(KX) ppm. more preferably varying from about 1 ppm to about 2000 ppm. even more preferably varying from about ? ppm to about 20(X) ppm by weight of the stream of the monomers including styrene.
Accordingly, in third embodiment, the present invention also relates to method of using the above-described amine based additive composition of the present invention to control and inhibit polymerization of aromatic vinyl monomers including styrene. wherein the method comprises treating the aromatic vinyl monomers including styrene with the said additive composition.
In accordance with one of the embodiments of the present invention, one or more said QM. one or more said phenolic compounds, and said aliphatic tertiary amine may be added to the monomers stream either individually or after mixing with each other.
It may be noted Unit all the features of the composition of die present invention described herein, a reference to which is drawn in entirely, are deemed to have been included in present method of using said additive composition of the present invention
Accordingly, in fourth embodiment, the present invention also relates to method for controlling and inhibiting polymeri/ation of aromatic vinyl monomers including ItylCIK, wherein the method comprises adding the said amine based additive composition of the present invention described herein to Ihc stream comprising aromatic vinyl monomers including styrene.
In accordance with one of the preferred embodiments of the present invention. the method for controlling and inhibiting polymerization of aromatic vinyl monomers including styrene by employing said additive composition of the present invention comprises adding an amount varying from about 0.01 ppm to about 5000 ppm. preferably varying from about 0.1 ppm to about 3000 ppm. more preferably varying from about 1 ppm to about 2000 ppm. even more preferably varying from about 5 ppm

lo uboul 2000 ppm of the said composilion to the aromatic vinyl monomers slream including styrene based on weight of die monomers.
In accordance wilh one of die embodiments of the present invention, one or more said QM. one or more said phenolic compounds, and said amine may be added to the monomers stream either individually or after mixing wilh each other.
It may be noted that all the features of the composition of Ihe present invention described herein, a reference to which is drawn in entirety, are deemed to have been included in Ihe present method for controlling and inhibiting polymerization of aromatic vinyl monomers including styrene by employing said additive composilion of the present invention.
In accordance with one of the embodiments of the present invention, the composition of the present invention may be mixed with stream containing aromatic vinyl monomers either before Ihc stream enters into processing syslcm or after Ihe stream has entered into processing system, but preferably the composition is added to the stream containing aromatic vinyl monomers before its processing starts so that polymerization of aromatic vinyl monomers is avoided or minimized.
In accordance with one of the embodiments of the present invention, the present composition may be used over a wide range of temperature varying from about 50 degree C to about 180 degree C. preferably from about 60 degree C lo about 180 degree C.
The composition of the present invention may be prepared in any known manner lo prepare ihe compositions.
Accordingly, in fifth embodiment, the present invention also relates lo a method for preparing said amine based additive composition of the present invention described herein for controlling and inhibiting polymerization of aromatic vinyl monomers including styrene. wherein one or more said QM. one or more said phenolic compounds may be mixed with said amine either individually or after mixing wilh each other.
In particular, in fifth embodiment. Ihe present invention relates to a method for preparation of additive composition of the present invention described herein, a reference to which is drawn in entirety, for controlling and inhibition of polymerization of aromatic vinyl monomers including styrene. wherein said method comprises:
step of mixing
(A) one or more quinonc mclhide or derivatives thereof nt:
In the following experiments, weighed amount of distilled siyrcne (or hydrocarbon stream in gms) and weighed amount of additives (in ppm by weight of styrene or hydrocarbon stream) were taken in a tube reactor equipped with thermometer and nitrogen inlet and outlet. In these experiments, enough N: How was maintained to ensure proper agitation The reactions were carried out at about I20UC under continuous nitrogen How for duration as mentioned in following tables. After the selected duration, the reactor was cooled to below about 1()UC by immersing in crashed ice. The contents of the reactor were then poured in a beaker. To this same beaker. approximately for about 1.5-2g chilled polymerization mixture, about 80g methanol was used to precipitate the polymer formed in the styrene solution. The precipitate

obtained was filtered, dried to remove methanol, and weighed. The weight of the preeipitate Conned is reported as % polymer formed.
It may be noted that styrene was purified before use to remove the stabilizers.
The Inventor has also found that neither the amine per se. for example TIPA per se. Quadrol per se, THEED per se is a styrene polymerization inhibitor, nor the phenolic compound per se. for example 2.6 I) IBP pet w. BHA per fir, BH'I per se is a stya-ne polymerization inhibitor (re Table VII. The 200 ppm dosage of T1PA per se from Sterling has tbOWH about 17.08% polymerization and TIP A per se from DOW has shown about 16.16% polymerization of the styrene. Similarly, the 200 ppm dosage of Quadrol per se has shown about 14.64% polymerization and THEED per se has shown about 14.34% polymerization of the styrene. Similarly. 2(X) ppm dosage of the 2. 6 DTBP per se has shown about 16.31% polymerization of the styrene. 200 ppm dosage Of the BHA per se has shown about 17.14% polymerization of the st\rcnc. and 2(X) ppm dosage of the BUT perse has shown about 15.68% pol> menzation of the styrene.
The combination of QM and the phenolic compound, the prior art additive for the present invention, has shown substantial polymerization of styrene. For example. the 100 ppm dosage of combination of QM and 2.6 DTBP when taken in a weight ratio of 90:10 has shown about 7.62% polymerization of the styrene. combination of QM and BHA in same weight ratio has shown about 10.41% polymerization of the styrene. and combination of QM and BHT in same weight ratio has shown about 7.8% polymeri/alion of die styrene. Similarly, die 200 ppm dosage of combination of QM and 2.6 DTBP when taken in a weight ratio of 90:10 has shown about 3.16% polymerization of die styrene. combination of QM and BHA in same weight ratio has shown about 6.96% polymerization oflhc styrene. and combination of QM and BHT in same weight ratio has shown about 3.68% polymerization of the styrene.
It may be noted that the combinations of QM and 2.6 DTBP. QM and BHA. and QM and BHT are the prior art compositions of the present invention, and the % polymerization of these combinations is the blank for the test results of the compositions of the present invention and the comparative amines.
Therefore, it would not be obvious to combine the aliphatic tertiary amine per se. for example. TIPA. Quadrol or THEED with the combination of QM and the phenolic COmpOUML i.e. 2.6 DTBP. BHA or BHT.

The Inventor has found thai when 4 ppm or 20 ppm of TEA. DEA. MEA or TBA is added to 100 ppm dosage of a combination of QM and 2.6 DTBP in a weight ratio of 90:10. the % polymerization of the styrene does not improve (Re Table I).
The Inventor has found that when 4 ppm of Quadrol® is added to 100 ppm dosage of a combination of QM and 2.6 DTBP in a weight ratio of 90:10. the % polymerization of the styrcne reduces to about 6.15%, and on addition of about 20 ppm it reduces to about 4.86% (Re Table ll.
The Inventor has found that when 4 ppm of THEED is added to KM) ppm dotage of a combination of QM and 2.6 DTBP in a weight ratio of 90:10, the *& polymerization of the styrene reduces to about 6.72%. and on addition of about 20 ppm it reduces to about 5.08f/f (Re Tabic 11
However, the Inventor has found that when 4 ppm of TIPA is added to 100 ppm dosage of a combination of QM and 2.6 DTBP in a weight ratio of 90:10. the % polymerization of the styrene substantially reduces to about 4.48%. and on addition of about 20 ppm it substantially reduces to about 3.08% (Re Table I).
Therefore, it would not be obvious to combine die TEA. DEA. MEA or TBA instead of the aliphatic tertiary amine with the combination of QM and the phenolic compound, i.e. 2.6 DTBP.
Same technical effects have been seen with the combinations of QM and BHA (Re table II I. and QM ajid BHT (Re table 111) for 100 ppm dosage.
With above unexpected and surprising findings the inventor has found that when 20 ppm of TIPA. Quadrol or THKKD is added to 200 ppm dosage of the lomhinalion of QM and 2. 6 DTBP. the % polymerization of styrene. respectively. reduces substantially from 3.18^ to 0.21%. 0.5341 and 0.44%. On the contrary, the change with addition of TEA. MEA and DEA is marginal (Re Tabic - IV).
Similarly, with above unexpected and surprising findings the inventor has found that when 20 ppm of TIPA. Quadrol or THEED is added to 200 ppm dosage of the combination of QM and BHA. the % polymerization oi styrene, respectively, reduces substantially from 6 5W to 0349 . I 690$ and I.549J. On the contrary, substantially no change is observed with addition of TEA. DEA and MIA i Re Tabic - V).
Similarly, with above unexpected and surprising findings the inventor has found that when 20 ppm of TIPA. Quadrol or THEED N added to 200 ppm dosage of the combination of QM and BHT. the CA polymerization of styrene. respectively, reduces

substantially from 3.68% to 0.32%. 1.38% and 1.42%. On ihc contrary, substantially no change is observed with addition of TEA. DEA and ME A (Re Table - VI).
The inventor has also found that the prior art additive - a combination of QM and 1IQ also does not show substantial improvement on addition of the amine of the present invention, i.e. a combination of QM and HQ with TIPA (re Tables Vlll-X).
The inventor has also carried out experiments with prior art additive - quinonc mcthidc (4 Ben/ylidene. 2.6 di Ten Butyl Cyclohexa-2.5 dicrotic) for 600 ppm dosage for \ arious duration of lime varying up to 3(H) mins for comparison purpose.
The experiments with prior art additives a combination of QM and 2.6 DTBP. and ■ combination of QM and HQ were also carried for a composition comprising 6U0 ppm of QM and 85 ppm of phenolic compound for various duration of time varying up to 3(H) mins for comparison purpose (re Tabic VIII). and for a comparative combination Of QM and HQ with TIPA arc also carried for a composiiion comprising 6(H) ppm of QM. 85 ppm of phenolic compound and either 18 ppm or 30 ppm of TIPA for various duration of time varying up to 300 mins for comparison purpose (re Table X).
The experiment with die present additive compositions comprising a combination of QM and 2.6 DTBP with TIPA were also carried for a composition comprising 6(K) ppm of QM. 85 ppm of phenolic compound and either 18 ppm or 30 ppm of TIPA for various duration of time varying up to 300 mins for comparison purpose (re Table IX).

Time
imin) 'X Polymerization unh 600 ppm of QM. 85 ppm of HQ. and 18 ppm of TIPA lX Polymerization with 600 ppm of QM. 85 ppm of HQ. and 30 ppm of TIPA
30 0 0
60 0.40 035
90 0.90 0 72
120 1.07 093
l>0 1.91 ! IS
180 2.18 196
210 2.61 2.21
240 3.52 3.03
270 6.62 5.79
300 9.05 7 52
As can be observed from above experiments, on addition of 18 ppm of TIPA in 685 ppm of combination of "QM (600 ppm) and 2-6 DTBP (85 ppm)", the "°o polymerization" reduces substantially.
Similarly, on addition of 30 ppm of TIPA in 685 ppm of combination of "QM (600 ppmi and 2-6 DTBP (85 ppm)", the "°o polymerization" reduces substantially .
As can be observed from above experiments, on addition of 18 ppm of TIPA in 685 ppm of combination of "QM (600 ppm) and HQ (85 ppm)". the "°o polymerization" does not reduce substantially.
Similarly, on addition of 30 ppm of TIPA in 685 ppm of combination of "QM (600 ppm) and HQ (85 ppm)"". the °o polymerization" does not reduce substantially.
All of above experiment*, confirm that only the present additive compositions comprising mixture of QM and phenolic compound and aliphatic teitiarv amine of the

present invention result in improvement of polymerization inhibition efficiency of the prior art additive consisting of a combination of QM and phenolic compound.
The above findings confirm that the present composition is more economical and environment friendly than prior art composition consisting of mixture of QM and phenolic compounds.
1 he above findings also confirm synergistic, surprising and unexpected effects of the present composition.
Above experimental results tJtO confirm that the presently provided composition is far superior than the prior art additive compositions, and hence, has technical advantages and surprising effects over the prior art additives

Claims
1. An improved amine based additive composition for controlling and inhibiting
polymcri/alion of aromatic vinyl monomers including styrene comprising:
(A) one or more qui none melhide or derivatives thereof (QM),
(B) one or more phenolic compounds, and characterized in thai the said composition further comprises:
(C) at least one amine comprising aliphatic tertiary amine containing -OH
group in the alky! chain.
2. The additive composition as claimed in claim I. wherein the aliphatic tertiary amine containing hydroxyl group in the alkyl chain comprises tri-isopropanol amine ortris(2-hydroxypropyl)amine «TIPA).
3. The additive composition as claimed in claim I or claim 2. wherein the aliphatic tertiary amine containing hydroxyl group in the alkyl chain comprises N.N.N'.N-Tetrakis (2-hydroxyethyl) ethylene-diamine (THEED). N.N.N'.N'-Tetrakis (2-hydroxypropvl> ethylene-diamine DTBPl. butylatcd hydroxy anisole (BHA). butylated hydroxy toluene (BHT). or a mixture thereof.
5. The additive composition as claimed in any one of the preceding claims. wherein the said quinone melhide or derivatives thereof (QM) comprises ben/yl quinone melhide. preferably 4-ben/.ylidenc.2.6-di-tert-bulyl cyclohexa-2.5-dicnone.
6. A method of using the additive composition as claimed in any one of the preceding claims to control and inhibit polymerization of aromatic vinyl monomers including styrene, wherein the method comprises treating the aromatic vinyl monomers including styrene with the said additive composition.
7. A method for controlling and inhibiting polymerisation of aromatic vinyl monomers including styrene. wherein the method comprises adding the said additive composition as claimed in any one of the preceding claims to the siream comprising aromatic vinyl monomers including stvrcne.
8. The method as claimed in claim 7 or claim 8. wherein the additive composition il added to the siream containing aromatic vinyl monomers including styrene in

an amount varying from about 0.01 ppm lo about 5000 ppm. preferably varying from about 0.1 ppm lo about 3000 ppm. more preferably varying from about 1 ppm to about 2000 ppm. even more preferably varying from about 5 ppm to about 2(HK) ppm by weight of the stream of the monomers including styrcne 9. The method as claimed in claim 7 or claim 8. wherein the additive composition is used at a temperature varying from about 50 degree C to about ISO degree ('. preferably from about 60 degree C to about ISO degree C.

Clean Version ! Claims amended under Article 34 of PCT
I
I I. An improved amine based additive composition for controlling and inhibiting polymerization of aromatic vinyl monomers including styrcne cumprising:
(A) one or more quinonc raedude or dcrivntives thereof (QM),
(B) one or more phenolic compounds, and characterized in that the said composition further comprises:
(C) at least one amine comprising aliphatic tertiary amine containing -OH
group in the alkyl chain;
wherein the quinonc methide or derivatives thereof (QM) comprises benzyl quinone methide, preferably 4-benzylidene.2.6-di-tert-butyl cyclohcxa 2.5-dienone;
wherein the phenolic compound comprises 2,6-di-tert-butyl phenol (2,6 DTBP), butylatcd hydroxy anisole (BHA). butylated hydroxy toluene (BHT), or a mixture thereof; and
wherein the aliphatic tertiary amine comprises tri-isopropanol amine or tris(2 hydroxypropy|)amine (T1PA). N.N,N\N'-TetrakiB (2-hydroxycthyl) ethylene-diamine (THEED), N,N,N\^Tctrakis (2-hydroxypcopyl) ethylene^iamme (Quadrof*), or mixture thereof.
2. A method of using the additive composition as claimed in claim 1 to control and inhibit polymerization of aromatic vinyl monomers including styrcne, wherein the method comprises treating the aromatic vinyl monomers including styrene with the said additive composition.
3. A method for controlling and inhibiting polymerization of aromatic vinyl monomers including styrene, wherein the method comprises adding the said additive composition as claimed in claim 1 to the stream comprising aromatic vinyl monomers including styrcne.
4. The method as claimed in claim 2 or claim 3, wherein the additive composition is added to the stream containing aromatic vinyl monomers including styrene in
an amount varying from 0.01 ppm to 5000 ppm, preferably varying from 0.1 I