Claims:We Claim:

1. HNIPU (hydroxyl non-isocyanate polyurethane) pre-polymers comprising stable cyclic carbonate backbone based amine terminated HNIPU prepolymers which is a copolymer of:

(i) precursor cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000;
(ii) polyamines;
said precursor cyclic carbonate to polyamine mole ratio being from 1:1.1 to 1:2 and said copolymer has amine hydrogen equivalent (AHEW) levels in the range 190-600.

2. HNIPU pre-polymers as claimed in claim 1 wherein said polyamines involves a combination of cycloaliphatic amine and linear aliphatic amine.

3. HNIPU pre-polymers as claimed in claims 1 or 2 wherein said stable cyclic carbonate backbone is preferably a hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers having functional groups including amines and hydroxyls apart from the carbamate linkages; wherein said amines are curable with epoxy moieties adapted for epoxy amine coatings or with isocyanates adapted for hybrid polyurethane urea coatings, and wherein said pendant -OH functionality with every carbamate group is adapted for baking to provide 1K (one component) thermoset systems with the -OH groups curing by themselves.

4. HNIPU pre-polymers as claimed in claim 1-3 wherein said (i) precursor cyclic carbonate comprises partially carbonated different backbone based precursors as blend cyclic carbonate sourced of epoxy precursors including Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) having BADGE:ESBO ratio range of 1:99 to 75:25.

5. HNIPU pre-polymers as claimed in claims 1-4 wherein said (i) involves blend of partially carbonated ESBO: partially carbonated BADGE in 60:40 wt. ratio with epoxy equivalent levels of 1300-2000 corresponding to 40-80% of epoxy converted carbonate.

6. HNIPU pre-polymers as claimed in claims 1-5 wherein said (i) cyclic carbonate and (ii) polyamine when taken in said ratio range of 1:1.1 to 1:2 results in stable amine terminated HNIPU pre-polymers and includes excess amine that passes accelerated stability test @ 55oC for at least 30 days, and does not self cure at said temperature.

7. HNIPU pre-polymers as claimed in claims 1-6 wherein said (ii) polyamine involving combination of cycloaliphatic amine and linear aliphatic amine is in mole ratio range of 0.45-0.9:0.2-1.1.

8. HNIPU pre-polymers as claimed in claims 1-7 wherein said select epoxy precursor bisphenol A epoxy resin (BADGE) having epoxy equivalent in the range of 170-300 enables faster drying vis-à-vis diglycidyl ether of hydrogenated bisphenol-A having same epoxy equivalent in the range of 170-300 providing for slower drying characteristics upon curing with epoxy resin.

9. HNIPU pre-polymers as claimed in claims 1-8 wherein said select combination of epoxy precursor includes 0.1 to 3% of diglycidyl ether of hydrogenated bisphenol-A with epoxy equivalent weight in the range of 450-3000 adapted for improved flow leveling of films.

10. HNIPU pre-polymers as claimed in claims 1-9 wherein said copolymer having amine hydrogen equivalent range in between 190-600 is adapted for faster drying in the range of 3-8 hr.

11. HNIPU pre-polymers as claimed in claims 1-10 wherein said copolymer having solid content of said pre-polymers/ binder in the levels of 65-70% (depending on solid content Gardner scale viscosity in the range of I to Z7 range).

12. HNIPU pre-polymers as claimed in claims 1-11 that is curable/ cross-likable with epoxy moieties sourced of epoxy monomers/ polymers/ resins or combinations thereof free of any catalyst adapted for curable formulations/thermosets/coating films thereof including ambient temperature cured films with sandability of the film only after 3-5h, improved mechanical and flow leveling properties, gloss, drying, curing efficiency, re-coatability of said cured HNIPU based films.

13. HNIPU pre-polymers as claimed in claims 1-12 as a curable formulation preferably a fast curable/ curing ambient temperature curable formulation comprising said
I(i) epoxy precursor based precursor cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000;
I(ii) polyamines preferably involving combination of cycloaliphatic amine and linear aliphatic amine; and
(II) epoxy moieties sourced of epoxy monomers/ polymers/ resins or combinations thereof.

14. A process for manufacturing HNIPU pre-polymers as claimed in claims 1-13 comprising the steps of

(i) providing epoxy precursor and partially reacting with CO2 to obtain precursor cyclic carbonate having residual epoxy equivalent weight (EWE) levels of 800-4000; and

(ii) reacting said precursor cyclic carbonate with polyamines preferably involving combination of cycloaliphatic amine and linear aliphatic amine in precursor cyclic carbonate to amine mole ratio is from 1:1.1 to 1:2 and obtaining said copolymer based HNIPU pre-polymer therefrom having amine hydrogen equivalent (AHEW) levels in the range 190-600, free of any catalysts.

15. A process for manufacturing HNIPU pre-polymers as claimed in claim 14

wherein said step (i) of providing epoxy precursors involves providing a blend of Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) as epoxy precursors having BADGE:ESBO ratio range of 1:99 to 75:25 and partially reacting with CO2 in the presence of Tetra butyl ammonium bromide (TBAB) to obtain said partially carbonated epoxy based cyclic carbonate blend adapted for hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers;
said step (ii) involves reacting said epoxy precursor based cyclic carbonate blend that is partially carbonated, with polyamines including Isophorondiamine (IPDA) in the temperature range of 40-120 ?C preferably at about 80oC for 2-5 hr preferably for 2.30 hr, and thereafter adding Triethylenetetramine (TETA) and continued for 2-8 hrs preferably 4.30 hr until amine hydrogen equivalent levels in the range of 190-600 preferably in the range of 272-350 is reached and obtaining therefrom said hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers, free of any catalysts.

16. A process for manufacturing HNIPU pre-polymers as claimed in claims 14 or 15 wherein said step (i) preferably involves reacting said blend of epoxy polymer with CO2 in the presence of Tetra butyl ammonium bromide (TBAB) with initial CO2 supply pressure of about 18 bar in organic solvent preferably o-xylene at temperature of about 150 ?C by maintaining the CO2 supply pressure at 38-40 bar for about 9.30hrproviding for partially carbonated ESBO: partially carbonated BADGE in 60:40 wt. ratio with epoxy equivalent levels preferably in the range of 1300-2000 corresponding to 40-80% of epoxy converted carbonate.

Dated this the 16th day of July, 2019 Anjan Sen
Of Anjan Sen and Associates
(Applicants Agent)
IN/ PA-199
, Description:FIELD OF THE INVENTION

The present invention provides for HNIPU (hydroxyl non-isocyanate polyurethane) pre-polymers comprising stable hybrid cyclic carbonate backbone derived amine terminated HNIPU prepolymers comprising copolymers of polyamines and cyclic carbonate precursor having residual epoxy equivalent weight levels in the range of 800-4000, which is further curable with epoxy moieties at temperatures including ambient temperatures or with isocyanates adapted for curable formulations/ thermosets/ coating films/ hybrid polyurethane urea type coatings free of any catalysts. More particularly, a process for preparing said HNIPU pre-polymers/ binders are also provided.

BACKGROUND ART

Thermosets of Non-Isocyanate Polyurethanes (NIPUs) can beobtained by the blend of cyclic carbonates or polycylic carbonate and amines or polyamines. NIPUs can be also obtained by thereaction of cyclic carbonated monomer or polymers and diamines. According to the literature, it isknown that the NIPUs obtained from carbonated monomers/polymers are cured using different aliphatic, cycloaliphatic and aromatic diamines at elevated temperature. In order to improve the reaction kinetics or fastening of the carbonate/amine reaction at ambient temperature, several researchers have been dedicated to the developmentof novel catalysts for synthesizing the thermosets of NIPUs at ambient temperature. Thermosets of NIPUs films having poor solvent resistance.

On this reference is drawn to CN 109593451in which a bisphenol AF and the perfluoro epoxy compound are used as raw materials, the bisphenol AF and the perfluoro cyclic carbonate are synthesized under the CO2 atmosphere and a high-performance non-isocyanate polyurethane coating is further prepared with different amine curing agents; wherein the preparation method of bisphenol AF cyclic carbonate comprises the steps: adding a bisphenol AF-based epoxy compound into a high-pressure reaction kettle, adding a double organic solvent, adding a catalyst, introducing carbon dioxide to maintain the pressure at 0.5-4.0Mpa, reacting, controlling the reaction temperature to be 60-180° and reacting for 2-40h; the non-isocyanate polyurethane coating prepared by the preparation method has very good hydrophobic, oleophobic and corrosion-resistant performances, high hardness, excellent impact resistance and chem. resistance and is expected to be a multifunctional coating for replacing traditional polyurethane. This prior work employs fluorinated Bisphenol–A as the precursor material.
Progress in Organic Coatings (2019), 127, 359-365, teaches a non-isocyanate polyurethane (NIPU) synthesized by cyclic carbonate resins (CC) and amines satisfies the growing awareness of environmental protection and attracts increasing research interest. However, CC are often prepared by CO2 and epoxy resin under high temperature and high pressure for a satisfactory conversion rate. This preparation process not only requires special equipment, but also causes the high cost of CC. To promote the synthesized method of CC, herein, we reported the successfully prepn. of CC under atm. pressure with excellent properties. O-chloro alc. resins were first synthesized by polyol reacted with anhydride and epichlorohydrin (ECH). This resins then reacted with sodium bicarbonate (NaHCO3) to offer CC under atm. pressure. The structures of CC were characterized by FTIR and 1H NMR. The NIPU were prepd. with CC and amines at different molar ratios. It was found that the NIPU films exhibited high hardness up to 2H as well as good adhesion. It also has excellent thermal stability with the initial thermal decomposition temp. up to 260 °C (the molar ratio of CC: isophoronediamine (IPDA) = 1:1). To further improve the chemical resistance of NIPU film, the NIPU was modified with epoxy resins. NIPU film with 40 wt% of E-20 exhibited excellent chemical resistance. Surprisingly, this NIPU film also displayed excellent flexibility and good impact resistance (100 cm.kg).Starting material for this prior art are O-chloro alcohol resins, polyol reacted with anhydride and epichlorohydrin providing for HNIPU prepared by different amines with excess curing with epoxy resins.

Abstracts of Papers, 256th ACS National Meeting & Exposition, Boston, MA, United States, August 19-23, 2018 (2018), POLY-609 provides for adhesive and mechanical properties of hybrid polyhydroxyurethane-epoxy network polymers, said polyhydroxyurethanes are an environmentally friendly non-isocyanate based alternative to more traditional polyurethanes. They are formed from the reaction between multifunctional amines and cyclic carbonate (CC) monomers. For practical applications, cyclic carbonate resins can be difficult to formulate as they are often very viscous or cryst. solids and require the use of solvents or reactive diluents to form films or bulk polymer. CC resins can be blended with epoxy resins to produce hybrid network structures wherein the functionality and cross-link of the network can be tuned depending on the feed ratio of CC and epoxy resins. In this work, trimethoylpropanetriglycidylether (TMPTGE) was converted to the trifunctional CC (TMPTGECC). TMPTGE and TMPTGECC were combined at various ratios and cured with bis-(p-aminocyclohexyl) methane (PACM). The mechanical behavior of the network polymers was characterized by dynamic mech. anal. (DMA) and tensile testing with digital image correlation. The adhesive properties of the materials were also characterized with single-lap-joint testing of grit blasted aluminum substrates at room temperature. It was found that with increasing levels of TMPTGECC, Mc increased along with simultaneous increases in Youngs modulus, yield stress, and toughness. It was also observed that the peel strength and displacement at complete failure also increased with increasing TMPTGECC content, this prior art thus involves adding epoxy resin in cyclic carbonate resin.

Progress in Organic Coatings (2017), 112, 169-175 teaches a series of novel cyclic carbonate-functionalized polysiloxanes (CC) prepared by the reaction of epoxy-functionalized polysiloxanes with carbon dioxide. Then the CCs with different carbonate content were reacted with various structural diamines such as isophorondiamine (IPDA), 4,4'-diaminodicyclohexylmethane (PACM), 1,2-proplenediamine (PDA) and 1,6-hexamethylenediamine (HMDA) to form non-isocyanate polyurethane (NIPU) coatings, resp. The precursor material involved in this prior art is epoxy-functionalized polysiloxanes.

RSC Advances (2017), 7(46), 28841-28852 teaches polyurethane/epoxy hybrid materials from CO2-sourced monomer prepared via an environmentally-friendly and non-toxic route, which avoided the use of toxic isocyanate. A series of non-isocyanate polyurethane (NIPU)/epoxy hybrid materials, with different and controlled architectures, were synthesized from CO2, polypropylene glycol diglycidyl ether (PPGDGE), amines and diglycidyl ether of bisphenol-A (BADGE). Around 12 wt.% CO2 was incorporated into PPGDGE to form a five-membered cyclic carbonate (5CC-PPGDGE). The complete conversion and selectivity of PPGDGE were obtained. The kinetics of 5CC-PPGDGE was investigated by reacting it with 1,2-ethylenediamine (EDA) at different temperature NH2-terminated pre-polymers were obtained by reacting 5CC-PPGDGE with various excessive amines. Finally, the hybrid materials were obtained by curing pre-polymers with BADGE. The results showed that a high content of amine with more functional groups led to better mechanical performances than diamine-based hybrid materials. This is the first time that architectures have been controlled by altering the amine ratio and functionality. And these hybrid materials exhibited satisfactory mechanical performances. The DETA-based and TETA-based materials with high amine ratio exhibited a tensile strength of 15.0 MPa and 12.5 MPa, accompanied with elongation at break of 151.3% and 170.9%, resp. The gel content, glass transition temperature and thermodynamic stability went up first and then declined with the increase of amine ratio, which demonstrated the architectures of hybrid materials ranged from defective to crosslinked and linear structures. This prior art is thus directed to homo polymers of polypropylene glycol diglycidylether(PPGDGE), amines and the pre-polymer attained thereof was cured with diglycidyl ether of bisphenol-A (BADGE).Thus reaction of PPGDGE with CO2 and reaction of carbonate attained thereof with high content of amine/ excess amine and altering the amine ratio is disclosed to achieve better mechanical performance minus any glossy feature in line with prior known fact that PPGDGE does not provide for any glossy output, wherein the BADGE is for curing purposes only to provide for hybrid materials.

CN 106118172 teaches an aluminum alloy container body, and the inner wall and outer wall of the aluminum alloy container body are resp. provided with a heavy-duty anticorrosion coating. The heavy-duty anticorrosion coating is prepared from epoxy cyclic carbonate 25-35, non-isocyanate polyurethane 23-33, cashew phenolic amine 12-24, nanotitania concentrated pulp 5-10, sintered epoxy powder 10-20, solvent 30-40 and fluoroalkyl-polysiloxane 15-25 parts. In this prior art non-isocyanate polyurethane is added in this formulation.

Progress in Organic Coatings (2016), 101, 461-467 teaches a series of bio-based non-isocyanate polyurethane (NIPU) coatings prepared via the ring-opening polymerization of rosin-based cyclic carbonate with amines. Then the NIPUs were modified with epoxy and cyclic carbonate-functionalized polyhedral oligomericsilsesquioxanes (POSS) to form NIPU/POSS coatings, respectively. The properties of the NIPU and NIPU/POSS coatings were determined, and the influences of POSS on mechanical and thermal properties of the resulting coatings were investigated. The results showed that by introducing POSS into the NIPU networks, the water tolerance, pencil hardness and thermal stabilities of the NIPU/POSS coatings were improved obviously with the increasing of the POSS content, but the impact strength, adhesion and flexibility of NIPU/POSS coatings were not observed to be affected to a significant extent. This prior art thus teaches NIPU made from cyclic carbonate-functionalized polyhedral oligomericsilsesquioxanes (POSS) and amine.

Progress in Organic Coatings (2015), 89, 160-169, teaches conventional polyurethanes, in spite of their excellent properties and wide applications possess safety and handling issues related to isocyanate compounds while synthesis. The cyclic carbonate-amine reaction resulting into hydroxyurethane is said to be an isocyanate free polyurethane system and novel route of synthesis as well as good alternative to conventional polyurethanes. In the present work, non-isocyanate polyurethane was synthesized by modification of dehydrated castor oil fatty acid (DCOFA) with tris-2-hydroxy-Et isocyanurate (THEIC). The synthesis involved three steps viz esterification of DCOFA with THEIC, epoxidn. of the ester formed (TEFA) and subsequent cyclocarbonation of THEIC-ester of fatty acid (CTEFA). The products obtained were confirmed by fourier transform IR spectroscopy (FTIR) as well as 1H and 13C nuclear magnetic spectroscopy (NMR). The CTEFA was cured with various amines such as di-Me di-Phsulfone (DDS), isophoronediamine (IPDA) and hexamethylenediamine (HMDA) to obtain NIPU coatings. The cured coatings were studied for chemical, mechanical, thermal and electrochemical properties. Also, the effect of amine curing agents on the performance of NIPU coatings was investigated. Experimental results showed that incorporation of THEIC into the system significantly improved coating properties. Non-isocyanate polyurethane in this prior art wassynthesized by modification of dehydrated castor oil fatty acid (DCOFA) with tris-2-hydroxy-Et isocyanurate (THEIC).

CN 103333323 A teaches a method for preparing the curing agent comprises the steps of: weighing cyclic carbonate and polyamine at a mole ratio of (0.1-1):1, batch-adding cyclic carbonate to a reactor filled with the amine, reacting, weighing thiourea 0.5-2.5 times the molar wt. of the amine, batch-adding thiourea to the reactor, reacting, cooling to 80°C, adding accelerant 0.5-5% of total mass of product in the reactor, stirring, discharging, and sealing. The curing agent is different from traditional curing agent, contains polyurethane flexible chain section synthesized from non-isocyanate, and has good toughness and impact strength. Polyamine containing thiourea bond inside the curing agent exists in ketone-form and enol-form balance state. The enol-form compound can react with epoxy group rapidly, cures epoxy completely in winter, and shortens working period effectively.Thiourea is employed in this prior art.

CN 102731779 A teaches hybrid non-isocyanate polyurethanes are prepared by the steps, (a) mixing epoxy resin (E-21, E-44 or E-51) and catalyst at 60-150° in an autoclave, replacing gas in the autoclave by CO2 for three times, keeping CO2 pressure at 0.5-2 MPa, reacting for 1-4 h to obtain cyclic carbonate with terminal group containing epoxy group, (b) reacting the cyclic carbonate with amine selected from ethylene amine, hexamethylenediamine, polyethylene polyamine or their mixture in solvent at 30-60° for 2-10 h to obtain hybrid non-isocyanate polyurethane soln., (c) pouring into a mold, removing solvent, standing at room temp. for 24 h, and heating at 50° for 48 h. Thus, E44 200 g, tetrabutylammonium bromide 1 g were heated at 80° in carbon dioxide atm. 1.0 MPa for 3 h to give cyclic carbonate product; the product 100 g, dioxane 200 mL, triethylamine 0.5 g, ethylene diamine 12 g were reacted for 9 h to give polyurethane soln.; the soln. was filled in PTFE mold, evaporated at room temperature for 24 h, then at 50° for 48 h to give a polyurethane sheet showing tensile strength 1.7 MPa, elongation at break 211%. This prior art involves copolymerization of DGEBA epoxy.

CN 106008966 A teaches reaction of CO2 and epoxy soybean oil to synthesize soybean oil-based five-membered cyclic carbonate; reaction of CO2 and bisphenol A diglycidyl ether to synthesize bisphenol A cyclic carbonate; and reaction of the two kinds of cyclic carbonate with amine to synthesize hybrid non-isocyanate polyurethane. This prior art provides good comprehensive mechanical performance and simple preparation method. This prior art teaches carbonated ESOB and carbonated BADGE to react with amine to synthesize hybrid HNIPU, which vulcanizes and self cures to give a vulcanized product and does not relate to any shelf stable HNIPU prepolymer that can be later cured with epoxy resin and does not self sure.

Hence it is the need in the art to provide for shelf stable amine terminated NIPU prepolymers or thermosetting NIPUs that would be stable by involving reaction between cyclic carbonate and polyamines without the use of any catalyst, which may further proceed to be cured/crosslinked by epoxy monomers/ polymers or resin thereof at ambient temperatures, and would not self cure, to thus not only provide for thermosetting NIPUs and thermosets thereof having better performance and gloss ascompared to known thermosets of NIPUs, would also provide for isocyanate based curing adapted for hybrid polyurethane urea coatings, and would further be capable of being baked in also having pendant-OH functionality with every carbamate group to provide 1K (one component) thermoset systems with the -OH groups curing by themselves.

OBJECTS OF THE INVENTION

It is thus the basic object of the present invention to provide for HNIPU prepolymers that is hybrid cyclic carbonate backbone based amine terminated HNIPU prepolymers that would be shelf stable and attainable free of any involvement of catalyst.

It is another object of the present invention to provide for said hybrid cyclic carbonate backbone based amine terminated HNIPU prepolymers and a process thereof that would not only be stable but would also be curable at temperatures including ambient temperatures with epoxy moieties free of any curing catalyst, and would also not self sure to lead to any vulcanized product.

It is yet another object of the present invention to provide for ambient temperature based fast curable formulation system free of catalyst providing for cured NIPU based coating films with anyone or more characteristics of sandability of said film only after 3-5h, improved mechanical and flow leveling properties, gloss, drying, curing efficiency, and re-coatability of such cured NIPU films.

It is yet another object of the present invention to provide a process for the synthesis of said hybrid cyclic carbonate backbone based amine terminated HNIPU prepolymers that would result in a stable prepolymer based on the reaction of a select hybrid cyclic carbonate with excess polyamine,preferably involving a combination of cycloaliphatic amine and linear aliphatic amine, at room temperature to elevated temperature free of involvement of any catalyst.

It is yet another object of the present invention to provide for cured said stable hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymer with epoxy moieties including epoxy monomers/ polymers/ resins that may be provided as a curable formulation.

SUMMARY OF THE INVENTION

Thus according to the basic aspect of the present invention there is provided HNIPU (hydroxyl non-isocyanate polyurethane) pre-polymers comprising stable cyclic carbonate backbone derived amine terminated HNIPU prepolymers which is a copolymer of:

(i) precursor cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000;
(ii) polyamines;
said precursor cyclic carbonate to polyamine mole ratio being from 1:1.1 to 1:2 and said copolymer has amine hydrogen equivalent (AHEW) levels in the range 190-600.

Preferably, said HNIPU pre-polymers involves polyamines that is a combination of cycloaliphatic amine and linear aliphatic amine.

Advantageously, said HNIPU pre-polymers wherein said stable cyclic carbonate backbone is preferably a hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers having functional groups including amines and hydroxyls apart from the carbamate linkages; wherein said amines are curable with epoxy moieties adapted for epoxy amine coatings or with isocyanates adapted for hybrid polyurethane urea coatings, and wherein said pendant -OH functionality with every carbamate group is adapted for baking to provide 1K (one component) thermoset systems with the -OH groups curing by themselves.

According to a preferred aspect of the present invention there is provided said HNIPU pre-polymers wherein said (i) precursor cyclic carbonate comprises partially carbonated different backbone based precursors as blend cyclic carbonate sourced of epoxy precursors including Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) having BADGE:ESBO ratio range of 1:99 to 75:25.

Preferably in said HNIPU pre-polymers wherein said (i) involves blend of partially carbonated ESBO: partially carbonated BADGE in 60:40 wt. ratio with epoxy equivalent levels of 1300-2000 corresponding to 40-80% of epoxy converted carbonate.

According to yet another preferred aspect of the present invention there is provided said HNIPU pre-polymers wherein said (i) cyclic carbonate and (ii) polyamine when taken in said ratio range of 1:1.1 to 1:2 results in stable amine terminated HNIPU pre-polymers and includes excess amine that passes accelerated stability test @ 55oC for at least 30 days, and does not self cure at said temperature.

Preferably, said HNIPU pre-polymers is provided wherein said (ii) polyamine preferably involving combination of cycloaliphatic amine and linear aliphatic amine is in mole ratio range of 0.45-0.9:0.2-1.1 and preferable wt. ratio range of 45-90% : 20-110%.

According to another preferred aspect of the present invention there is provided said HNIPU pre-polymers wherein said select epoxy precursor bisphenol A epoxy resin (BADGE) having epoxy equivalent in the range of 170-300 enables faster drying vis-à-vis diglycidyl ether of hydrogenated bisphenol-A having same epoxy equivalent in the range of 170-300 providing for slower drying characteristics upon curing with epoxy resin.

Preferably in said HNIPU pre-polymers said select combination of epoxy precursor includes 0.1 to 3% of diglycidyl ether of hydrogenated bisphenol-A with epoxy equivalent weight in the range of 450-3000 adapted for improved flow leveling of films.

More preferably said HNIPU pre-polymers comprising said copolymer having amine hydrogen equivalent range in between 190-600 is adapted for faster drying in the range of 3-8 hr.

Preferably said HNIPU pre-polymers comprises said copolymer having solid content of said pre-polymers/ binder in the levels of 65-70% (depending on solid content Gardner scale viscosity in the range of I to Z7 range).

According to another preferred aspect of the present invention there is provided said HNIPU pre-polymers that is curable/ cross-likable with epoxy moieties sourced of epoxy monomers/ polymers/ resins or combinations thereof free of any catalyst adapted for curable formulations/thermosets/coating films thereof including ambient temperature cured films with sandability of the film only after 3-5h, improved mechanical and flow leveling properties, gloss, drying, curing efficiency, re-coatability of said cured HNIPU based films.

Preferably said HNIPU pre-polymers as a curable formulation is preferably a fast curable/ curing ambient temperature curable formulation comprising said
I(i) epoxy precursor based precursor cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000;
I(ii) polyamines preferably involving combination of cycloaliphatic amine and linear aliphatic amine; and
(II) epoxy moieties sourced of epoxy monomers/ polymers/ resins or combinations thereof.

According to another aspect of the present invention there is provided a process for manufacturing HNIPU pre-polymers comprising the steps of

(i) providing epoxy precursor and partially reacting with CO2 to obtain precursor cyclic carbonate having residual epoxy equivalent weight (EWE) levels of 800-4000; and

(ii) reacting said precursor cyclic carbonate with polyamines preferably involving combination of cycloaliphatic amine and linear aliphatic amine in precursor cyclic carbonate to amine mole ratio is from 1:1.1 to 1:2 and obtaining said copolymer based HNIPU pre-polymer therefrom having amine hydrogen equivalent (AHEW) levels in the range 190-600, free of any catalysts.

Preferably in said process for manufacturing HNIPU pre-polymers
wherein said step (i) of providing epoxy precursors involves providing a blend of Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) as epoxy precursors having BADGE:ESBO ratio range of 1:99 to 75:25 and partially reacting with CO2 in the presence of Tetra butyl ammonium bromide (TBAB) to obtain said partially carbonated epoxy based cyclic carbonate blend adapted for hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers;
said step (ii) involves reacting said epoxy precursor based cyclic carbonate blend that is partially carbonated, with polyamines including Isophorondiamine (IPDA) in the temperature range of 40-120 ?C preferably at about 80oC for 2-5 hr preferably for 2.30 hr, and thereafter adding Triethylenetetramine (TETA) and continued for 2-8 hrs preferably 4.30 hr until amine hydrogen equivalent levels in the range of 190-600 preferably in the range of 272-350 is reached and obtaining therefrom said hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers, free of any catalysts.

According to another preferred aspect of said process for manufacturing HNIPU pre-polymers said step (i) preferably involves reacting said blend of epoxy polymer with CO2 in the presence of Tetra butyl ammonium bromide (TBAB) with initial CO2 supply pressure of about 18 bar in organic solvent preferably o-xylene at temperature of about 150 ?C by maintaining the CO2 supply pressure at 38-40 bar for about 9.30hr providing for partially carbonated ESBO: partially carbonated BADGE in 60:40 wt. ratio with epoxy equivalent levels preferably in the range of 1300-2000 corresponding to 40-80% of epoxy converted carbonate.

DETAILED DESCRIPTION OF THE INVENTION

As discussed hereinbefore, the present invention provides for HNIPU pre-polymerscomprising stable hybrid cyclic carbonate backbone derived amine terminated HNIPU prepolymers which is a copolymer of:
(i) precursor cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000;(ii) polyamines;said precursor cyclic carbonate to polyamine mole ratio being from 1:1.1 to 1:2 and said copolymer has amine hydrogen equivalent (AHEW) levels in the range 190-600.

Preferably, said polyamine is a combination of cycloaliphatic amine and linear aliphatic amine.

According to an embodiment of the present invention said precursor cyclic carbonate is (i) blend cyclic carbonate having residual select epoxy equivalent levels 1300-2000 comprising partially CO2 reacted epoxy precursors of different backbone including Bisphenol A (BADGE)andepoxidized soybean oil (ESBO) in the ratio of BADGE:ESBO of 1:99 to 75:25;
(ii) polyamines involves combination of cycloaliphatic amine and linear aliphatic amine;
said precursor cyclic carbonate to polyamine mole ratio being in the levels of from 1:1.1 to 1:2 is thus adapted to generate said copolymer having amine hydrogen equivalent (AHEW) levels in the range 190-600.

Advantageously,said stable hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers thus generated as per its constitution has functional groups including amines and hydroxyls apart from the carbamate linkages and provides for following select characteristics:
accelerated stability @ 55oC for at least 30 days;
said amines are curable with epoxy moieties adapted for epoxy amine coatings or with isocyanates adapted for hybrid polyurethane urea coatings, and wherein said pendant -OH functionality with every carbamate group is adapted for baking to provide 1K (one component) thermoset systems with the -OH groups curing by themselves.

Preferably,said stable amine terminated HNIPU pre polymers are curable with epoxy moieties at temperatures including ambient temperatures.

Said precursor cyclic carbonate is a hybrid cyclic carbonate sourced of different backbone based epoxy precursors including commercially available epoxy resins made from Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) when surprisingly partially reacted with CO2 providing for blendcyclic carbonate having said residual epoxy levels in the levels of 800-4000 which when further reacted with a combination of polyamines could effectively provide for said stable cyclic carbonate backbone based amine terminated HNIPU pre-polymers having select characteristics as above, which otherwise could not be obtained.

Preferably when Carbonated ESBO: carbonated BADGE is blended in select 60:40 wt. ratio then reacted with polyamines provided for improved drying time and stability issues.

Importantly, it was found that not all the epoxy of precursor epoxy preferably ESBO and BADGE blend based epoxy was required to be carbonated to achieve the desired characteristics as above, but it was essential to control the epoxy to carbonate conversion to retain residual epoxy equivalent levels of 800-4000 of the cyclic carbonate blend corresponding to conversion of epoxy to carbonate between 40-80% that was further proceeded for reaction with polyamines to provide for said shelf stable amine terminated HNIPU prepolymer. Not only the above control, but it also necessary to have Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) in the ratio of BADGE:ESBO of 1:99 to 75:25 in case of epoxy combination based blend cylic carbonate to attain the desired shelf stability.

Added to the above, said polyamines are selected from various amine structures such as from cycloaliphatic amine and linear aliphatic amine, further preferably when taken in a specified ratio, also plays a key role directed to control the target objectives of the pre-polymer towards attaining the shelf stability like that of thermoplastic binder and its related drying kinetics.
Preferably polyamine involving combination of cycloaliphatic amine and linear aliphatic amine is in wt. ratio range of 45-90% : 20-110% and mole ratio range of 0.45-0.9:0.2-1.1.

Thus importantly, the absence of such controls with regard to the select residual epoxy equivalent levels of precursor cyclic carbonate preferably cyclic carbonate blend involving BADGE:ESBO based epoxy resin even when taken in select ratio levels, together with polyamines taken in a select ratio with respect to the cyclic carbonate wherein absence of such controls sometimes including control on select combination of amines, otherwise, leads to an unstable and gelled product that did not pass the conventional accelerated stability test @ 55oC for at least 30 days used for testing the stability of thermoplastic binders. Thus such is the surprising select constitution of the present invention leading to the target objectives.

Essentially thus the total polyamine is also present in select ratio with that of total carbonate such that excess amine is present that further improves the stability and performance of amine terminated HNIPU prepolymers.

Therefore with the total polyamine present in select ratio with that of total carbonate is not only to have excess amine on one hand to kill the remnant epoxy of the thus generated thermoplastic binder, but also smoothly enables further curing/crosslinking of the amine terminated HNIPU with epoxy moieties including epoxy monomers/ polymers/ resins or combinations thereof to provide for a coating having the desired characteristics of good gloss, together with improved mechanical properties and also curing efficiency.

According to another aspect of the present invention there is provided a stable amine terminated HNIPU pre-polymer based curable coating formulation comprising
(i) said stable excess amine terminated HNIPU pre-polymers,
(ii) epoxy moieties;
adapted for curing/ crosslinking and generation of coating films that cures at temperatures including ambient temperature free of catalyst and having diverse glossy, mechanical and flow leveling properties.

Advantageously, the attributes of curable coating formulation including ambient temperature curable formulation attained without any catalyst provides sandability of the film after 3-5h with the coating films showing(i) good mechanical and flow leveling properties; (ii) gloss; (iii) drying, curing efficiency, sandability and re-coatability of the thus cured NIPU much improved vis-à-vis other curing technologies.

Thus significantly it was found by way of the present invention that even when different backbone based epoxy precursors were employed for cyclic carbonate synthesis with CO2 thus providing for cyclic carbonate blend, such as by reaction of commercially available epoxy resins made from Bisphenol A (BADGE) and epoxidized soybean oil (ESBO) with CO2, said blend cyclic carbonate not only has to have select residual EEW levels but should also involve polyamines preferably including a select combination of cycloaliphatic amine and linear aliphatic amine for generation of amine terminated HNIPU prepolymers.

Further the above synthesized stable HNIPU pre-polymers further crosslink with epoxy moieties including epoxy monomers/ polymers/ resins or combinations thereof to provide for a coating having the desired characteristics of good gloss, together with improved mechanical properties and also curing efficiency/ faster drying performances.

EXAMPLES:
The below non-limiting examples illustrate attainment of select HNIPU pre-polymers that is shelf stable, and further curable with epoxy moieties preferably curable at ambient temperatures to meet the desired glossy and mechanical properties of the top coat with improved curing kinetics. Said HNIPU pre-polymers of the present invention are also curable with isocyanates adapted for hybrid polyurethane urea coatings, and wherein said pendant -OH functionality with every carbamate group is adapted for baking to provide 1K (one component) thermoset systems with the -OH groups curing by themselves.

Reaction of epoxidized soybean oil (ESBO) and GY250 with carbon dioxide
The blend of Carbonated soybean oil (CSBO)/gy250 was obtained in the reaction of the commercial Epoxidized soybean oil ESBO and Bisphenol A based epoxy (Gy250) with CO2 carried out in the presence of Tetra butyl ammonium bromide (TBAB) and condition are shown in Table 1.
Simple ESBO instead of the blend could also be employed as shown in Table 2.
Table 1: Representative formulation:
Sr. no. Ingredient Wt %
1 ESBO/gy250 32.26/48.38
2 TBAB 3.23
3 o-xylene 16.13
4 Pressure initial supply 18 bar
5 Temperature 152
6 After 150 temperature pressure maintained 38-40 bar
7 time 9.30hr
Total 100

Table 2: Representative formulation:
Sr. no. Ingredient Wt %
1 ESBO/gy250 80.64
2 TBAB 3.23
3 o-xylene 16.13
4 Pressure initial supply 18 bar
5 Temperature 152
6 After 150 temperature pressure maintained 38-40 bar
7 time 9.30hr
Total 100

Results for both Table 1 and Table 2 formulations
Solids (120oC for 1 hour) 85±2%
EEW (g/epoxide) 1300 - 2000

Synthesis of Amine terminated HNIPU with blending of cyclic carbonate and blend of amine:

The above synthesized ESBO and Gy20 cyclic carbonate was reacted with Isophorondiamine (IPDA) at 80oC for 2.30 hr, then after addition of TETA amine and continue for 4.30 hr and check the Amine hydrogen equivalent (AHEW) by titration.

Table: 4 Representative formulation for Amine terminated HNIPU
Sr. no. Ingredient Wt %
1 Carbonate of Gy250/ESBO 53.5
2 IPDA(Isophorondiamine) 8.12
3 o-xylene 29.55
Stirring started at 200 RPM
Temperature-80,2.30hr
4 Addition of TETA(triethylenetetramine) 8.83
Continue for 80,for 4.30-5 hr
AHEW value 272-350
Total 100

Table 5: Curing studies of amine terminated HNIPU of the present invention with epoxy resin (Gy250)

Formulation:
Sr.No Ingredient WT %
1 Amine terminated H-NIPU resin 40.2
2 GY250 25.3
3 O-Xylene 34.5
Total 100

Comparative Results:

Sl. no.1 60:40 wt. ratio (best)
Broad and Preferred Ratio range
Workability range cyclic carbonate of BADGE:ESBO is 1:99 to 75:25
Below the ratio that does not work
Below range cyclic carbonate of BADGE:ESBO is 1:99 Beyond the ratio that does not work
Beyond range cyclic carbonate of BADGE:ESBO is 75: 25 Glossy, Mechanical characteristics of the top coat together with improved drying characteristics when cured with epoxy resin
Partially carbonated ESBO: partially carbonated BADGE blend as precursor and the resulting characteristics of shelf stability of amine attained upon reaction with polyamines starting from this precursor.

Pass accelerated stability @ 55oC for 30 days
Pass accelerated stability @ 55oC for 30 days

Pass accelerated stability @ 55oC for 30 days

fails in Accelerated stability @ 55oC for 30 days

NA
(Not applicable)
Sl. no. 2 Best epoxy equivalent level
1300-2000 800-4000 corresponding to epoxy to carbonate conversion between 40-80%range, and preferred range Below the range800 Beyond the range4000

Epoxy equivalent of Partially carbonated single ESBO ORepoxy equivalent of partially carbonated single BADGE with the resulting characteristics of shelf stability of amine attained upon reaction with polyamines starting from this precursor

Pass accelerated stability @ 55oC for 30 days

Pass accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

NA
(Not applicable)
Epoxy equivalent of Partially carbonated ESBO: partially carbonated BADGE blend and the resulting characteristics of shelf stability of amine attained upon reaction with polyamines starting from this precursor

Pass accelerated stability @ 55oC for 30 days

Pass accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

NA
(Not applicable)
Sl. no. 3 With linear aliphatic amine With cycloaliphatic amine With mixture of linear aliphatic amine + cycloaliphatic amine at broader ratio range
Ratio of cyclic carbonate: linear aliphatic + cyclo aliphatic
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of 45-90%:20-110% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.45-0.9:0.2-1.1) Preferred amine ratio of cyclo: linear showing best results
Ratio of cyclic carbonate: linear aliphatic + cyclo aliphatic
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of 65 to 85%:30 to 70% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.65 to 0.85 :0.7 to 0.3)

Partially carbonated blend at best ratio of 60:40, and, best epoxy equivalent / Partially carbonated single epoxy blend at best epoxy equivalent, for reaction with polyamines providing for the resulting characteristics of shelf stability
Fails in accelerated stability @ 55oC for 30 days
Stable system without chasing binder parameters passes accelerated stability @ 55oC for 30 days, and is curable.

Pass accelerated stability @ 55oC for 30 days
Pass accelerated stability @ 55oC for 30 days
Detection of Image value:92 and R value (R Value(Combo Ford rating (Combination of DOI, Gloss and Orange Peel): 6.2
konig pendulum hardness :54.8
Pencil hardness:4H
Sl. no. 4 Best ratio
Ratio of cyclic carbonate: linear aliphatic+cyclo aliphatic amine
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of 65%+70% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.65:0.7) Broad and preferred ratio range
Ratio of cyclic carbonate: linear aliphatic+cyclo aliphatic amine
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of 65 to 85%:30 to 70% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.65 to 0.85 :0.7 to 0.3) Below the ratio that show less desired results
Ratio of cyclic carbonate: linear aliphatic+cyclo aliphatic amine
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of less than 45%:20% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.45:0.2) Beyond the ratio that show less preferred results does not work
Ratio of cyclic carbonate: linear aliphatic+ cycloaliphatic amine
CYCLOALIPHATIC:ALIPHATIC weight ratio is in the range of more than 90%:110% based on 100 gram of cyclic carbonate.
(one mole of cyclic carbonate is required CYCLOALIPHATIC : ALIPHATIC in the range of 0.9:1.1 )

Partially carbonated single epoxy precursor based carbonate/ blend epoxy precursor based carbonate: total amine ratio providing for the desired amine equivalent and providing for the resulting characteristics of shelf stability

PASS in accelerated stability @ 55oC for 30 days

PASS in accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

Fails in accelerated stability @ 55oC for 30 days

(Unstable HNIPU pre-polymers cannot be proceeded with like above to impart the desired characteristics)

The present invention therefore provides precursor cyclic carbonate/ blend thereof with residual EEW levels preferably provides for a carbonated ESBO: carbonated BADGE blend combination, having said carbonated ESBO and BADGE with remnant select epoxy equivalent levelswhich when reacted with polyamines preferably aselect combination of polyamines, preferably taken in select ratio, not only provides for shelf stability of amine terminated HNIPU pre-polymer thus generated but also when cured with epoxy resin is adapted to favour glossy characteristics, desired mechanical performance (like that of acrylic or alkyd top coats) together with improved curing kinetics of the top coat preferably at temperatures including ambient temperatures.
Glossy appearance together with improved mechanical performance and curing kinetics is difficult to be achieved from ESBO known to only impart glossy appearance/ characteristics, which challenge in the art could be overcome by the present invention based on select constitution of amine terminated HNIPU pre-polymer thus attained.

Thus the shelf stability imparting select epoxy equivalent EEW of the carbonated blend preferably involving select ratio levels carbonated ESOB: carbonated BADGE when goes into the reaction with polyamine advantageously provides for amine terminated shelf stable HNIPU prepolymerincludingexcess amine, that can be further cured with epoxy resin and does not self sure. Hence thethus generated microstructure of the pre-polymer favours the much desired property/ characteristics upon curing with moieties including epoxy moieties.

More importantly, and further to the aforesaid, the epoxy conversion of the carbonated blend to lead to precursor cyclic carbonate was controlled to provide for the desired remnant epoxy equivalent corresponding to epoxy to carbonate conversion of 40-80%to attain the desired shelf stable HNIPU pre-polymer with a controlled level of H-bonding resulting from the controlled level of hydroxyl urethane linkages generated upon reaction with polyamines preferably combination of polyamines thus arrests the gelling tendency to thus be shelf stable, such stability being further controlled by a combination of polyamines including cycloaliphatic amine having lesser reactivity. Thus the desired shelf stability of the pre-polymer that is curable, and not self cured, enables further curing with epoxy moieties.

The various combinations of hybrid cyclic carbonate backbone based amine terminated HNIPU pre-polymers could be thus attained based on select polyamines including select combination of different amines that yields stable HNIPU pre polymers having different physical properties (viscosity and amine hydrogen equivalent) or forms thermosets of HNIPU when cured with epoxy moieties including epoxy monomers/ polymers/ resins or combinations thereof. Finally ambient temperature curable coating formulation could also be provided comprising said stable amine terminated HNIPU prepolymerincluding excess amine when taken together in combination with epoxy moieties that could generate coating films having a wide array of gloss, mechanical and flow leveling properties.

Principally the present invention provides for the following:
1. Copolymerization by unique combination of cyclic carbonate having residual epoxy equivalent weight (EEW) levels of 800-4000 and amine in binder synthesis which results into excellent DOI(Distinctness of image) along with faster drying characteristics 3-4 h;
2. Various combinations with different structures are used as reactants and its process to prepare stable HNIPU pre polymers;
3. Twostep synthetic approaches comprising of a first step towards the synthesis of blend combination of cyclic carbonate and second synthetic step is towards obtaining amine terminated stable HNIPU pre polymers including excess amine that could easily react with epoxy polymers to provide for coats;
4. Cyclic carbonate ring opening with polyamines including different combination amines preferably involving varying ratio of amines andratio of cyclic carbonate: total amine, at room temperature to elevated temperature;
5. Curing said stable HNIPU pre polymer by cross linking with different epoxy polymers or isocyanates or can be baked;
6. Ambient temperature fast curable formulation/ system involving said HNIPU pre-polymer and epoxy moieties that cures without using any catalyst and sandability of the film after 3-5h is attained;
7. Coating films provides good mechanical and flow leveling characteristics for wood finish and floor coating applications.

The present advancement thus provides for stable amine terminated HNIPUs pre-polymers by the reaction between precursor cyclic carbonatehaving residual epoxy equivalent weight (EEW) levels of 800-4000 or a select blend thereof having said EEW levels and polyaminestaken in excess at elevated temperature without using any catalyst. These amine terminated HNIPUS including excess amines are then further reacted with epoxy ring containing moieties including monomer or polymers or resins or mixtures thereof provided as a cross linker at ambient temperature to achieve thermosetting NIPUs having better performance as compared to known NIPU thermosets.