EPOXY RESIN AND ONE-POT PREPARATION THEREOF

FIELD OF THE INVENTION

[0001] The present disclosure pertains to organic synthesis. In particular, the present disclosure pertains to organic synthesis of photo-curable acrylate/ methacrylate resins.

BACKGROUND OF THE INVENTION

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] In recent years, photo-induced polymerization has become a well-known technology owing to its large variety of industrial applications such as printing inks, coatings, adhesives, sealants, etc. Among numerous methods, ultraviolet (UV)-radiation curing is one of the most efficient ways to rapidly convert the liquid photosensitive resin to solid polymer within a fraction of a second. Ultraviolet-curable resins are the resins most suitable to the requirements of the times such as low pollution, resource conservation, high performance and functionalization. The oligomers and monomers commonly used in UV-curable formulations include acrylated compounds such as epoxy acrylate/ methacrylate (vinyl ester) resins, urethane acrylates, polyester and polyether acrylates and epoxy acrylate nanocomposites. Epoxy acrylate/methacrylate resins are (semi-) polymeric substances called oligomers with variable chain lengths that are widely applied as photo-sensitive substrate in various industries and manufacture because of the distinct properties such as great adhesion, corrosion resistance and hardness.

[0004] Amongst the epoxy acrylate resins, di-functional acrylates i.e, diacrylated epoxy resins are most commonly synthesized. The method of preparation of diacrylated epoxy resins typically involves the reaction of different epoxy resins (different phenols) with acrylic acid. Generally, diglycidal ethers comprising two epoxide functional groups are reacted with acrylic acid in the presence of quaternary ammonium compounds, alkyl amines, alkyl/aryl phosphines and Lewis acid catalyst, resulting in ring opening of epoxide or end-capping the epoxide groups with acrylate group to obtain diacrylated epoxy resin, as shown in Scheme 1.

Scheme 1: General Scheme for Epoxy Di-Acrylate

[0005] The diacrylated epoxy resin thus obtained has two secondary hydroxyl groups on the backbone of the oligomer chain, which do not further react with acrylic acid to form ester linkage, as their reaction is very sluggish. Additionally, the presence of secondary OH groups hinders the curing speed and also reduces the crosslinking density of the polymer, thus, weakening the physical, mechanical, chemical and thermal properties of the UV-cured

Scheme 2: Formation of Di- and Tetra-Acrylated Bisphenol A based Epoxy Resin

[0006] In attempts to synthesize multifunctional epoxy resins, in recent years, work towards the synthesis of tetra- acrylated epoxy resins is being reported. In one such process reported in US patent 5,650,462, depicted in Scheme 2, Bisphenol A diglycidal ether is reacted with acryloyl chloride in the presence of basic catalyst triethylamine (Et^N), resulting in formation of a mixture of di- and tetra-acrylated epoxy resins. Thus, though this process yields tetra- acrylated epoxy resin, the purity of the product obtained is very less. Furthermore, this reaction yields byproducts that are extremely hazardous; treatment and disposal of the effluents is an issue. The use of acryloyl chloride as an active ingredient for end-capping the epoxide and hydroxyl groups with acrylate function groups also has drawbacks. Acryloyl chloride is highly toxic, flammable, has a lachrymatory effect and is not very stable as it decomposes on contact with moisture, thus it cannot be stored in open environment. Moreover, toxic fumes of hydrochloric acid are generated throughout the reaction. [0007] In another reported procedure in patent no. US 3,845,009 as shown in Scheme 3, tetra-methacrylated epoxy resins have been synthesized starting from resorcinol diglycidal ether, which is reacted with methacrylic acid using base as a catalyst to form di -methacrylic Epoxy Resin. The dimethacrylated epoxy resin, thus obtained, is then reacted with methacryloyl chloride in presence of base catalyst triethylamine (EtsN) to end-cap secondary hydroxyl groups, resulting in tetra-methacrylic epoxy resin. The use of methacryloyl chloride has limitations similar to the use of acryloyl chloride such as methacryloyl chloride is flammable with low stability, toxic, corrosive, lachrymatory and generates extremely hazardous byproducts (toxic fumes of hydrochloric acid are generated throughout the

Scheme 3: Tetra-Methacrylated epoxy of resorcinol

[0008] Another reported method of synthesizing tetra-acrylated epoxy amino resin has been reported by Mohtadizadeh et al.; Progress in Organic Coatings', 2015, 231-239, wherein tetra-functional epoxy amino resin, namely tetra- amino -glycidyl ether is reacted with acrylic acid in presence of a basic catalyst, resulting in the formation of tetra-acrylated epoxy amino resin, as shown in Scheme 4. However, the secondary hydroxyl groups generated during this reaction do not react further and remain as such in the final compound. The presence of free secondary hydroxyl groups in this tetra-acrylated epoxy amino resin results in reduced crosslinking density and hinders the curing speed. The product thus obtained, weakens the physical, mechanical, chemical and thermal properties of the UV-cured product.

Scheme 4: Synthesis of tetra-functional epoxy amino resin [0009] Thus there is an urgent need to develop an improved UV-curable tetra- acrylated/ methacrylated epoxy resin and synthetic procedure for its synthesis, which can overcome the deficiencies associated with the known arts. Need is also felt for an improved UV-curable tetra- acrylated/ methacrylated epoxy resin, which has increased functionality, can be synthesized in high purity without any toxic byproduct formation, demonstrates improved crosslinking and curing speed and improves the physical, mechanical, chemical and thermal properties of the cured product.

OBJECTS OF THE INVENTION

[0010] An object of the present disclosure is to provide an improved photo-curable tetra- acrylated/ methacrylated epoxy resin and process for its synthesis, which can overcome deficiencies associated with the known arts.

[0011] Another object of the present disclosure is to provide a photo-curable multifunctional, tetra- acrylated/ methacrylated epoxy resin that demonstrates improved crosslinking and curing speed.

[0012] Yet another object of the present disclosure is to provide a photo-curable multifunctional tetra-acrylated/ methacrylated epoxy resin that improves the physical, mechanical, chemical and thermal properties of the cured product.

[0013] Another object of the present disclosure is to provide a photo-curable multifunctional tetra-acrylated/ methacrylated epoxy resin that can be synthesized in high purity and without any harmful byproduct formation.

[0014] Still another object of the present disclosure is to provide a one pot synthetic process for the synthesis of multifunctional tetra-acrylated/ methacrylated epoxy resin that does not involve any hazardous starting materials and provides product in high purity.

[0015] The other objects and preferred embodiments and advantages of the present disclosure will become more apparent from the following description of the present disclosure when read in conjunction with the accompanying examples and figures, which are not intended to limit scope of the present disclosure in any manner.

SUMMARY OF THE INVENTION

[0016] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in Detailed Description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. [0017] The foregoing and other objects are attained by the present disclosure, which relates to photo-curable multifunctional tetra-acrylated/ methacrylated epoxy resin and one pot synthetic process for its synthesis.

[0018] In the first aspect, the present disclosure relates to one pot synthesis process for the preparation of photo-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, including forming a di-acryl/ methacryl epoxy resin by reacting diglycidal ether with acrylic acid/ methacrylic acid in the presence of a catalyst; and converting di-acryl/methacryl epoxy resin into tetra-acrylated/ methacrylated epoxy resin by reaction with acrylic acid/ methacrylic acid in the presence of a heteropolyacid catalyst; wherein the di-acryl/ methacryl epoxy resin is not isolated after its formation and is in-situ reacted with acrylic acid/ methacrylic acid in the presence of heteropolyacid catalyst to obtain tetra-acrylated/ methacrylated epoxy resin.

[0019] The single pot process for the synthesis of multifunctional tetra-acrylated/ methacrylated epoxy resin according to the present disclosure enables the synthesis of tetra- acrylated / methacrylated epoxy resin in high purity and yield, without any harmful byproduct formation and the process does not involve any hazardous starting materials.

[0020] In the second aspect, the present disclosure relates to a photo-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, synthesized by one pot synthesis process, wherein the tetra-acrylated / methacrylated epoxy resin demonstrates improved crosslinking and curing speed that improves the physical, mechanical, chemical and thermal properties of the cured product.

[0021] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

DETAILED DESCRIPTION

[0022] The following is a detailed description of embodiments of the present disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0023] Unless the context requires otherwise, throughout the specification which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.” [0024] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0025] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0026] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, process conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.

[0027] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein.

[0028] All methods described herein can be performed in suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. [0029] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0030] Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[0031] Aspects of the present disclosure relate to one pot synthesis process for the preparation of photo-curable multifunctional tetra- acrylated/ methacrylated epoxy resin. The single pot process for the synthesis of multifunctional tetra-acrylated/ methacrylated epoxy resin according to the present disclosure enables the synthesis of tetra-acrylated/ methacrylated epoxy resin in high purity and yield, without any harmful byproduct formation and the process does not involve any hazardous starting materials. Further, the process of the present disclosure avoids the isolation of intermediate, thus making the process more efficient and cost-effective. Photo-curable resins are cured using radiation source such as UV light, visible light, electron beam and the like. Typically, UV radiation is used for curing epoxy resins since UV radiation is more energetic.

[0032] In the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, including forming a di-acryl/ methacryl epoxy resin by reacting diglycidal ether with acrylic acid/ methacrylic acid in the presence of a catalyst; and converting di-acryl/ methacryl epoxy resin into tetra-acrylated/ methacrylated epoxy resin by reaction with acrylic acid/ methacrylic acid in the presence of a heteropolyacid catalyst; wherein the di-acryl/ methacryl epoxy resin is not isolated after its formation and is in-situ reacted with acrylic acid/ methacrylic acid in the presence of heteropolyacid catalyst to obtain tetra-acrylated/ methacrylated epoxy resin. A general scheme depicting the one pot process is described in Scheme 5, wherein when R=H, the compound is acrylic acid and when R=CHs, the compound is known as methacrylic acid. Depending upon the acid used, i.e., acrylic acid or methacrylic acid, the corresponding di- or tetra- epoxy resin is obtained. The one pot process is therefore more efficient and cost-effective than the processes of prior art, because it obviates isolation and/or purification of the di-acryl/ methacryl epoxy resin. Further, the process according to the first aspect of the present disclosure provides tetra-acrylated/ methacrylated epoxy resin in high purity and without any harmful byproduct formation. The process of the present disclosure does not involve any hazardous starting materials like acid chlorides that are toxic, hazardous, lachrymatory and unstable.

Scheme 5: General Scheme for the synthesis of tetra -acrylated/ methacrylated epoxy resin

[0033] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra- acrylated/ methacrylated epoxy resin, wherein the reaction of di-acryl/ methacryl epoxy resin with acrylic acid/ methacrylic acid can occur at a temperature in the range of 40 °C to 100 °C and at pressure in the range of atmospheric pressure to 5 bars. In a preferred embodiment, the reaction can be carried out at 90 °C.

[0034] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra- acrylated/ methacrylated epoxy resin, wherein the catalyst for the synthesis of di-acryl/methacryl epoxy resin can be selected from but not limited to quaternary ammonium compounds such as tetra- n-butylammonium bromide (TBAB), cetyl trimethyl ammonium bromide (CTAB), trimethylammonium chloride; alkyl amines such as triethyl amine, dimethylbenzylamine; organophosphorus compound such as triphenylphosphine and lewis acid such as boron trifluoride. The reaction for the synthesis of di-acryl/methacryl epoxy resin can also take place in the presence of inhibitor such as hydroquinone (HQ) and anti-oxidant such as butylated hydroxy toluene (BHT).

[0035] In a preferred embodiment, the catalyst can be a quaternary ammonium compound tetra-n-butylammonium bromide.

[0036] In an exemplary embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated epoxy resin, wherein the one pot process results in the synthesis of bisphenol based tetra- acrylated epoxy resin, as shown in Scheme 6. According to Scheme 6, diglycidyl ether of bisphenol reacts with acrylic acid in the presence of quaternary ammonium compound resulting in epoxy di-acrylate of bisphenol, which is further reacted in the same pot with acrylic acid using heteropolyacid catalyst resulting in epoxy tetra- acrylate of bisphenol.

Scheme 6: Synthesis of Bisphenol based tetra-acrylated epoxy resin

[0037] In another exemplary embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra- methacrylated epoxy resin, wherein the one pot process results in the synthesis of bisphenol based tetra-methacrylated epoxy resin, as shown in Scheme 7. According to Scheme 7, diglycidyl ether of bisphenol reacts with methacrylic acid in the presence of quaternary ammonium compound resulting in epoxy di-methacrylate of bisphenol, which is further reacted in the same pot with methacrylic acid using heteropolyacid catalyst resulting in epoxy tetra-methacrylate of bisphenol.

Scheme 7: Synthesis of Bisphenol based tetra-methacrylated epoxy resin

[0038] In another exemplary embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional, tetra- acrylated epoxy resin, wherein the one pot process results in the synthesis of aromatic or aliphatic diols based tetra-acrylated epoxy resin, as shown in Scheme 8. According to Scheme 8, diglycidyl ether of diol (aromatic or aliphatic) reacts with acrylic acid in the presence of quaternary ammonium compound resulting in epoxy di-acrylate of diol, which is further reacted in the same pot with acrylic acid using heteropolyacid catalyst resulting in epoxy tetra-acrylate of the starting diol.

Scheme 8: Synthesis of diol based tetra-acrylated epoxy resin

[0039] In another exemplary embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional, tetra- methacrylated epoxy resin, wherein the one pot process results in the synthesis of aromatic or aliphatic diols based tetra-methacrylated epoxy resin, as shown in Scheme 9. According to Scheme 9, diglycidyl ether of diol (aromatic or aliphatic) reacts with methacrylic acid in the presence of quaternary ammonium compound resulting in epoxy di-methacrylate of diol, which is further reacted in the same pot with methacrylic acid using heteropolyacid catalyst resulting in epoxy tetra-methacrylate of the starting diol.

Scheme 9: Synthesis of diol based tetra-acrylated epoxy resin

[0040] According to the embodiments of the present disclosure, the heteropoly acid is a class of acid made up of a combination of hydrogen and oxygen with particular metals and non-metals. A heteropoly acid compound must contain an “addenda atom” (transition metal such as tungsten, molybdenum, vanadium, cobalt, zinc etc.); a “hetero atom” (such as silicon, phosphorus, arsenic etc.); oxygen, linked to the metal atom and acidic hydrogen atoms. The metal addenda atoms linked by oxygen atoms form a cluster with the hetero-atom inside bonded via oxygen atoms. Examples with more than one type of metal addenda atom in the cluster are well known. The conjugate anion of a heteropoly acid is known as a polyoxometalate. Different combinations of addenda atoms and different types of heteroatom can result in several different types of heteropolyacids. Two polyacids groups based on Keggin (HXMAU) and Dawson (H _r ,X ₂ M ₁₈ O ₆₂ ) structures can be represented as shown in the below Table.

[0041] In one embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, wherein the heteropolyacid catalyst can be an acid catalyst selected from phosphotungstic acid, phosphomolybdic acid, silicotungstic acid and the like. In a preferred embodiment, the heteropolyacid catalyst can be phosphotungstic acid. The heteropolyacid according to the embodiments of the present disclosure can be used in catalytic amount in the range of 0.1 to 5 wt%. , preferably in the range of 0.2 to 2 wt% and most preferably in the range of 0.3 to 1 wt%.

[0042] In yet another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, wherein the byproduct is water, which can be removed by reverse azeotropic distillation using dichloromethane as the solvent.

[0043] In still another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, wherein the product tetra-acrylated/ methacrylated epoxy resin can be formed in high purity and yield in the range of 95-98%.

[0044] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, wherein ratio of di-acryl/ methacryl epoxy resin and acrylic acid/ methacrylic acid used can be in the range of 1:2 to 1:2.5 equivalent.

[0045] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, wherein di-acrylated/ methacrylated epoxy resin can be prepared starting from diglycidyl ether selected from but not limited to resorcinol diglycidyl ether, bisphenol S-diglycidal ether, bisphenol A-diglycidal ether, bisphenol E-diglycidal ether, bisphenol F-diglycidal ether, butanediol diglycidal ether, hexanediol diglycidal ether, propanediol diglycidal ether, pentanediol diglycidal ether and the like.

[0046] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra- acrylated/ methacrylated epoxy resin, wherein di-acrylated/ methacrylated epoxy resin can be selected from but not limited to resorcinol based di-acrylated/ methacrylated epoxy resin, bisphenol S- based di-acrylated/ methacrylated epoxy resin, bisphenol A- based di-acrylated/ methacrylated epoxy resin, bisphenol E- based di-acrylated/ methacrylated epoxy resin, bisphenol F-based di-acrylated/ methacrylated epoxy resin, butanediol based di-acrylated/ methacrylated epoxy resin, hexanediol based di-acrylated/ methacrylated epoxy resin, propanediol based di-acrylated/ methacrylated epoxy resin, pentanediol based di-acrylated/ methacrylated epoxy resin and the like.

[0047] In another embodiment of the first aspect, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra- acrylated/ methacrylated epoxy resin, wherein the tetra-acrylated/methyacrylated epoxy resin can be selected from but not limited to resorcinol-based epoxy tetra-acrylate/methacrylate, bisphenol S- based epoxy tetra-acrylate/methacrylate, bisphenol A- based epoxy tetra- acrylate/methacrylate, bisphenol E- based epoxy tetra-acrylate/methacrylate, bisphenol F- based epoxy tetra-acrylate/methacrylate, butanediol based epoxy tetra-acrylate/methacrylate, hexanediol based epoxy tetra-acrylate/methacrylate, propanediol based epoxy tetra- acrylate/methacrylate, pentanediol based epoxy tetra-acrylate/methacrylate and the like.

[0048] In another embodiment, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylate epoxy resin, wherein the di-acrylated/ methacrylate epoxy resin has free secondary hydroxyl groups. [0049] In another embodiment, the present disclosure relates to one pot synthesis process for the preparation of UV-curable multifunctional tetra-acrylated/ methacrylate epoxy resin, wherein the tetra-acrylated/ methacrylate epoxy resin does not have any free secondary hydroxyl groups.

[0050] In the second aspect, the present disclosure relates to a UV-curable multifunctional tetra-acrylated/ methacrylated epoxy resin, synthesized by one pot synthesis process, wherein the tetra-acrylated/ methacrylated epoxy resin demonstrates improved crosslinking and curing speed that improves the physical, mechanical, chemical and thermal properties of the cured product. [0051] In one embodiment of the second aspect, the present disclosure relates to UV- curable multifunctional tetra- acrylated/ methacrylated epoxy resin that can be synthesized in high purity and without any harmful byproduct formation.

[0052] In another embodiment of the second aspect, the present disclosure relates to UV-curable multifunctional tetra- acrylated / methacrylated epoxy resin, synthesized by the one pot synthesis process, wherein the tetra- acrylated/ methacrylate epoxy resin, thus obtained can be further blended with suitable reactive diluents (viscosity modifiers), additives and photoinitiators according to the end application and irradiated under suitable wavelength of UV radiation, for curing and crosslinking. The diluents typically used in such reactions include polyester acrylate or urethane acrylate selected from TMPTA (Trimethylol propane triacrylate), HDDA (Hexanediol diacrylate), TPGDA (Tripropylene glycol diacrylate), PEGDA (Polyethylene glycol diacrylate), BDDA (Butanediol diacrylate) and the like. Additives that can be blended with tetra- acrylated/ methacrylate epoxy resin prepared according to the process of the present disclosure can include inhibitors, plasticizers, light stabilizers and the like. Photoinitiators that can be used can be selected from free radical (type 1 and type 2), cationic and anionic photoinitiators. In a preferred embodiment free radical type 1 photoinitiators are used for the curing process, wherein the photoinitiators are selected from but not limited to Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide (Irgacure 819, Ciba), 1 -Hydroxycyclohexyl -phenyl ketone (Irgacure 184, Ciba), Diphenyl (2 4 6- trimethylbenzoyl) phosphine oxide (TPO) and the like.

[0053] According to the embodiments of the present disclosure, the process of the present disclosure can be applied to prepare products with functionalities in the range of three to eight or more, depending upon the number of epoxides in the starting material used.

[0054] While the foregoing description discloses various embodiments of the disclosure, other and further embodiments of the invention may be devised without departing from the basic scope of the disclosure. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

[0055] The present disclosure is further explained in the form of following examples. However, it is to be understood that the foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention. [0056] All the raw materials used are commercially available and were purchased from local vendors. Diglycidal ether of Bisphenol A, Bisphenol F and Resorcinol were received from Atul Ltd and Bisphenol S was obtained from Hindustan Monomers Pvt. Ltd. Other raw materials were purchased from Merck. FT-IR was determined using Perkin Elmer Spectrum 100 FTIR. Agilent Cary 60 UV-Vis was for determining UV/Visible spectra. Waters 2414 RI detector 515 HPLC Pump was used for GPC. Mettler Toledo DSC 3 with Software version: STARe SW 16.00 was used for Differential Scanning Calorimetry (DSC). Perkin Elmer DMA 8000 with Software version Pyris 13.3.2.0030 was used as Dynamic Mechanical Analyzer (DMA). Mettler Toledo TGA/DSC 1 with Software version STARe SW 16.00, was used for Thermogravimetric Analysis (TGA). Bruker Advance 400Hz was used to record C Nuclear Magnetic Resonance (C NMR).

[0057] Example 1: Preparation of resorcinol based epoxy tetraacrylate

[0058] Under nitrogen atmosphere, diglycidal ether of resorcinol (222.24 g, 1 mole) was reacted with acrylic acid (158.5 g, 2.2 mole) in presence of quaternary ammonium compound tetra-n-butyl ammonium bromide (2.7 g, 0.5 wt%) which is used as phase transfer catalyst, inhibitor hydroquinone (0.27 g, 0.05 wt%) and antioxidant butylated hydroxytoluene (0.27 g, 0.05 wt%). Reaction temperature was raised to 90 °C and maintained for 12 h. At the end, part of the reaction mass was taken out to determine the acid value which is preferred less than 5 mg KOH/g. The product obtained is epoxy diacrylate of resorcinol.

[0059] In same pot having epoxy di-acrylate of Resorcinol, was further added acrylic acid (158.5g, 2.2 mole) in presence of heteropolyacid catalyst phosphotungstic acid (0.27 g, 0.05 wt%), solvent dichloromethane (80 g, 15 wt%) and inhibitor hydroquinone (0.27 g, 0.05 wt%). Reaction temperature was raised to 80 °C and esterification reaction was carried out using reverse azeotropic distillation where water of reaction was removed. At the end of the reaction the catalyst was filtered out, the product was alkali washed and vacuum distilled to remove solvent and water from it to obtain the final product epoxy tetra-acrylate of resorcinol (455 g, 96 %). ¹³ C-NMR (5, ppm): 159.59, 131.99, 131.42, 128.24, 127.78, 107.23, 101.76, 68.71, 67.92, 60.88. FT-IR (X, cm' ¹ ): 1729, 1635, 809.

[0060] Example 2: Preparation of Bisphenol S-based epoxy tetraacrylate

[0061] Under nitrogen atmosphere, diglycidal ether of bisphenol-S (362 g, 1 mole) was reacted with acrylic acid (158.5 g, 2.2 mole) in presence of quaternary ammonium compound tetra-n-butyl ammonium bromide (3.4 g, 0.5 wt%), which is used as phase transfer catalyst, accelerator copper(I) chloride (CuCl, 0.07 g, 0.01 wt%), solvent 1,4 dioxane (136 g, 20 wt%), inhibitor hydroquinone (0.34 g, 0.05 wt%) and antioxidant butylated hydroxytoluene (0.34 g, 0.05 wt%). Reaction temperature was raised to 90 °C and maintained for 8 h. At the end, part of the reaction mass was taken out to determine the acid value which is preferred less than 5 mg KOH/g. Further solvent was distilled under partial vacuum to obtain the desired product epoxy di-acrylate of Bisphenol-S.

[0062] In same pot having epoxy di-acrylate of bisphenol-S was further added acrylic acid (158.5g, 2.2 mole) in the presence of heteropolyacid catalyst phosphotungstic acid (3.4 g, 0.5 wt%), solvent dichloro -methane (102 g, 15 wt%) and inhibitor hydroquinone (0.34 g, 0.05 wt%). Reaction temperature was raised to 80 °C and esterification reaction was carried out using reverse azeotropic distillation where water of reaction was removed. At the end of the reaction the catalyst was filtered out, the product was alkali washed and vacuum distilled to remove solvent and water from it to obtain the final product epoxy tetra-acrylate of Bisphenol-S (601 g, 98 %). ¹³ C-NMR (5, ppm): 170.87, 162.07, 133.68, 132.22, 129.35, 127.81, 115.08, 67.78, 66.71, 60.59. FT-IR (X, cm' ¹ ): 1729, 1635, 809.

[0063] Example 3: Preparation of Bisphenol -A based epoxy tetra-acrylate

[0064] Under nitrogen atmosphere, diglycidal ether of bisphenol- A (340.41 g, 1 mole) was reacted with acrylic acid (158.5 g, 2.2 mole) in presence of quaternary ammonium compound tetra-n-butyl ammonium bromide (3.3 g, 0.5 wt%), which is used as phase transfer catalyst, inhibitor hydroquinone (0.33 g, 0.05 wt%) and antioxidant butylated hydroxytoluene (0.33 g, 0.05 wt%). Reaction temperature was raised to 90 °C and maintained for 12 h. At the end, part of the reaction mass was taken out to determine the acid value which is preferred less than 5 mg KOH/g. Further solvent was distilled under partial vacuum to obtain the desired product epoxy di-acrylate of Bisphenol-A.

[0065] In same pot having epoxy di-acrylate of bisphenol-A was further added acrylic acid (158.5g, 2.2 mole) in the presence of heteropolyacid catalyst phosphotungstic acid (3.3 g, 0.5 wt%), solvent dichloro -methane (99 g, 15 w%) and inhibitor hydroquinone (0.33 g, 0.05 wt%). Reaction temperature was raised to 80 °C and esterification reaction was carried out using reverse azeotropic distillation where water of reaction was removed. At the end of the reaction the catalyst was filtered out, the product was alkali washed and vacuum distilled to remove solvent and water from it to obtain the final product epoxy tetra-acrylate of Bisphenol-A (580 g, 98 %). ¹³ C-NMR (5, ppm): 166.43, 143.63, 131.62, 128.33, 128.12, 114.05, 68.72, 66.21, 60.21, 41.69, 31.04. FT-IR (X, cm ¹ ): 1729, 1635, 809.

[0066] Example 4: Preparation of Bisphenol-F based epoxy tetra-acrylate

[0067] Under nitrogen atmosphere, diglycidal ether of bisphenol-A (312.36 g, 1 mole) was reacted with acrylic acid (158.5 g, 2.2 mole) in presence of quaternary ammonium compound tetra-n-butyl ammonium bromide (3.15 g, 0.5 wt%), which is used as phase transfer catalyst, inhibitor hydroquinone (0.31 g, 0.05 wt%) and antioxidant butylated hydroxytoluene (0.31 g, 0.05 wt%). Reaction temperature was raised to 90 °C and maintained for 12 h. At the end, part of the reaction mass was taken out to determine the acid value which is preferred less than 5 mg KOH/g. Further solvent was distilled under partial vacuum to obtain the desired product epoxy di-acrylate of Bisphenol-F.

[0068] In same pot having epoxy di-acrylate of bisphenol-F was further added acrylic acid (158.5g, 2.2 mole) in the presence of heteropolyacid catalyst phosphotungstic acid (3.15 g, 0.5 wt%), solvent dichloro-methane (94g, 15 wt%) and inhibitor hydroquinone (0.31 g, 0.05 wt%). Reaction temperature was raised to 80 °C and esterification reaction was carried out using reverse azeotropic distillation where water of reaction was removed. At the end of the reaction the catalyst was filtered out, the product was alkali washed and vacuum distilled to remove solvent and water from it to obtain the final product epoxy tetra-acrylate of Bisphenol-F (547 g, 97 %). ¹³ C-NMR (5, ppm): 166.37, 166.12, 131.68, 131.39, 128.26, 114.61, 68.81, 66.13, 59.92, 40.11. FT-IR (X, cm ¹ ): 1729, 1635, 809.

[0069] Using the procedures described in Examples 1, 2, 3 and 4, and by replacing acrylic acid with methacrylic acid, diglycidal ether of resorcinol was converted to resorcinol based epoxy tetra-methacrylate, bisphenol-S diglycidal ether was converted to epoxy tetramethacrylate of bisphenol-S, bisphenol-A diglycidal ether was converted to epoxy tetramethacrylate of bisphenol-A and bisphenol-F diglycidal ether was converted to epoxy tetramethacrylate of bisphenol-F.

[0070] The foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.