WO2019002954A1

WO2019002954A1 - A stable conjugate aminosilane adduct

Info

Publication number: WO2019002954A1
Application number: PCT/IB2018/052653
Authority: WO
Inventors: Subarna Shyamroy; Sethuraman KOWSHIKRAMAN; Bhabani Prasad MALLIK; Anandkumar Balasaheb Shivarkar
Original assignee: Asian Paints Limited
Priority date: 2017-06-30
Filing date: 2018-04-17
Publication date: 2019-01-03

Abstract

The present disclosure relates to a stable conjugate aminosilane adduct and a process for preparation. The stable conjugate aminosilane adduct comprises at least one of epoxy compound or at least one acetoacetate compound; and at least one aminosilane compound. The stable adduct is characterized by an amine value in the range of 90 to 250 mgKOH/g and a viscosity in the range of 30 - 350 cps. The stable conjugate aminosilane adduct of the present disclosure provides longer pot life, does not require long induction time before application and shows comparatively less blushing in the coating.

Description

A STABLE CONJUGATE AMINOSILANE ADDUCT

FIELD

The present disclosure relates to a stable conjugate aminosilane adduct. DEFINITIONS:

As used in the present disclosure, the following words and phrases are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.

The expression 'blushing effect' refers to the curing of an amine based polymeric coating (film) which usually results in surface oiliness due to low/ambient temperature or high humidity.

The expression 'pot life' refers to the amount of time the processing properties of a raw material or semi-finished product are retained after final preparation (mixing of components, adding of catalysts, etc.).

The expression "amine value" refers to a convenient way of measuring the amino content of a sample. It is analogous to acid value and is defined as the number of milligrams of KOH equivalent to the basicity in one gram of sample. The expression "amine equivalent weight (AEW)" refers to a calculated value determined from the amine value. The amine equivalent weight is calculated as: 56.1X1000 / amine value = Amine equivalent weight (AEW).

BACKGROUND

Conventionally, epoxy resins have been successfully used in the formation of corrosion resistant coatings. These coatings are applied with a solvent solution using a brush, a roller, or a spray gun. However, the solvents used for applying the various types of coating agents are not environmentally friendly and are detrimental to human health. Therefore, the use of solvents in the coatings needs to be reduced or eliminated. Further, the toxicity of certain curing agents used in the epoxy resin formulations can be hazardous. Also, the volatility of certain amines used for curing epoxy resins, can under certain conditions, create potential health risks.

Films prepared from epoxy resins and cured with amines are also known; however, at low/ambient temperature or high humidity, curing of the polymeric coating (film) based on amine usually results in surface oiliness, commonly referred to as "amine-blush", "blushing" or "sweating". Amine blush results due to the tendency of amine functional curing agents to react with moisture and carbon dioxide in the atmosphere before reaction with the epoxy groups. The reaction product, called carbamate is white in color and gets deposited onto the surface, thereby spoiling the appearance, giving a stained, blotchy (discoloration) look, loss in gloss, poor gloss retention, poor adhesion and recoatability, and are slow to cure, i.e., take a long time to reach an acceptable degree of hardness; and are not readily usable in a water- borne system.

Therefore, there is felt a need to provide a composition for coating that overcomes the aforestated drawbacks. OBJECTS

Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.

It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative. An object of the present disclosure is to provide a stable conjugate aminosilane adduct that itself act as a binder.

Another object of the present disclosure is to provide a stable conjugate aminosilane adduct that result in comparatively less blushing in the coating.

Still another object of the present disclosure is to provide a stable conjugate aminosilane adduct that has enhanced coating properties such as pencil hardness, scratch hardness, taber abrasion, adhesion, surface resistivity, pendulum hardness, and DFT. Yet another object of the present disclosure is to provide a stable conjugate aminosilane adduct having a longer pot life and that does not require long induction time before application.

Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY

The present disclosure relates to a stable conjugate aminosilane adduct and a process for preparing the same. The stable conjugate aminosilane adduct comprises at least one epoxy compound or at least one acetoacetate compound; and at least one aminosilane compound. The stable conjugate aminosilane adduct can be epoxide-aminosilane adduct or acetoacetate- aminosilane adduct. The adduct is characterized by an amine value in the range of 90 mgKOH/g to 250 mg KOH/g and a viscosity in the range of 30 cps to 350 cps. The viscosity of the adduct of the present disclosure is stable and increases by a maximum of 10% by accelerated stability test. In one embodiment, the viscosity of the adduct increases by 7% by accelerated stability test.

Further, the present disclosure relates to a process for preparing the stable conjugate aminosilane adduct. The process comprises reacting at least one epoxy compound or at least one acetoacetate compound with at least one amino silane compound optionally in the presence of at least one catalyst. The epoxy compound can be selected from the group consisting of a monoepoxy compound and a polyepoxy compound. The proportion of monoepoxy compound to amino silane compound can be in the range of 3:97 to 70:30 wt/wt% and the proportion of polyepoxy compound to amino silane compound can be in the range of 3:97 to 40:60 wt/wt%. The acetoacetate compound can be at least one selected from the group consisting of ethyl acetoacetate, methyl acetoacetate, propyl acetoacetate, butyl acetoacetate, tertiary butyl acetoacetate, cyclohexyl acetoacetate and phenyl acetoacetate, acetoacetate functional monomer and acetoacetate functional polymer and the like. The proportion of acetoacetate compound to amino silane compound can be in the range of 3:97 to 50:50 wt/wt%.

Still further, the stable conjugate aminosilane adduct of the present disclosure can be used itself as a binder to form a film on a substrate. The so obtained film has hardness greater than 0.5 kg, typically in the range of 2.5 kg to 4 kg. The conjugate aminosilane adduct comprises at least one epoxide-aminosilane adduct or at least one acetoacetate-aminosilane adduct. The stable conjugate aminosilane adduct of the present disclosure provides longer pot life, does not require long induction time before application and shows comparatively less blushing in the coating. DETAILED DESCRIPTION

The present disclosure relates to a conjugate aminosilane adduct. Proposed solutions to avoid the blushing problem are often provided in the form of new amine hardeners, amine with high AHEW value (amine hydrogen equivalent weight), polymer with high EEW value (epoxide equivalent weight), use of nonreactive diluents (polyoxypropylene polyols), use of reactive diluents (epoxy or acrylate containing diluents), decrease in gel time (e.g. curing at high temperature, which allows some induction time between mixing and coating) and process change (e.g. curing in a dry environment, curing in a carbon dioxide free atmosphere, handling and storage of the amine hardener in inert atmosphere, etc.) However, these approaches have several drawbacks such as longer dry time, shorter gel time, and poor hardness.

Therefore, the present disclosure provides a stable conjugate aminosilane adduct and a process for preparing the same, which overcomes the aforestated drawbacks.

In one aspect of the present application, there is provided a stable conjugate aminosilane adduct which is used as a curative for organic and inorganic hybrid coatings such as epoxy siloxane/ acrylic siloxane. The stable conjugate aminosilane adduct comprises at least one epoxy compound or at least one acetoacetate compound; and at least one aminosilane compound. The stable conjugate aminosilane adduct can be epoxide-aminosilane adduct or acetoacetate-aminosilane adduct. The adduct is characterized by having an amine value in the range of 90 mgKOH/g to 250 mgKOH/g, solids in the range of 30 % to 60 % and a viscosity in the range of 30 cps to 350 cps. The so obtained adduct is flowable, un-gelled and has extended shelf stability. The adduct of the present disclosure can be used as crosslinker and can be used as binder.

Typically, when the adduct of the present disclosure is used as crosslinker or as a binder, it is stored in a solvent prior to use. The solvent can be selected from the group consisting of a non-polar solvent and a polar solvent. In accordance with the present disclosure, the polar solvent is selected from the group consisting of polar protic and polar aprotic solvents and combinations thereof, and the non-polar solvent is selected from the group consisting of aliphatic non-polar solvents and aromatic non-polar solvents and combinations thereof. Typically, the solvent can be selected from the group consisting of alcohols, esters, and ketones. Alcohols, such as ethanol, methanol, propanol, isopropanol etc; esters such as ethyl acetate, methyl acetate, propyl acetate, butyl acetate, benzyl acetate etc; and ketone such as acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), acetophenone, butanone, etc, can be used as solvent in the present disclosure.

The viscosity of the adduct of the present disclosure is stable and increases by a maximum of 10% by accelerated stability test. In one embodiment the viscosity of the adduct increases by 7% by accelerated stability test. The method of accelerated stability testing of the products is based on the principles of chemical kinetics, such as temperature, humidity, pH, viscosity, etc. The stability data of the substance determines the optimal storage conditions.

The epoxy compound can be at least one selected from the group consisting of a mono epoxy compound and a poly epoxy compound. The monoepoxy compound can be at least one selected from the group consisting of Phenyl glycidyl ether, glycidyl ester of Versatic Acid (Cardura E10), and Glycidyl neodecanoate (Glydexx N-10). Typically, aliphatic monoepoxy compounds can be used. The proportion of monoepoxy compound to aminosilane compound can be in the range of 3:97 to 70:30 wt/wt%.

The polyepoxy compound can be at least one selected from the group consisting of Epoxy Novolac Resin (™DEN 431), Epoxy solvent cut resin (Lapox P-101 (ARP-11X75), Liquid epoxy resin based on bisphenol-A (Lapox B-l l (ARB-11)), epoxy phenol novolac resin having functionality 3.6 (Araldite EPN 1180), Bisphenol F type epoxy (YDF 170), Epoxy resin of hydrogenated Bisphenol A (YDH 3000), and bisphenol A/F epoxy resin with monofunctional reactive diluent (Araldite GY 783). The proportion of polyepoxy compound to aminosilane compound can be in the range of 3:97 to 40:60 wt/wt%.

The acetoacetate compound can be at least one selected from the group consisting of ethyl acetoacetate, methyl acetoacetate, propyl acetoacetate, acetoacetate functional monomer, acetoacetate functional polymer, and the like. Typically, the acetoacetate compound can be ethyl acetoacetate and Methacrylate with acetoacetate group. The proportion of acetoacetate compound to aminosilane compound can be in the range of 3:97 to 50:50 wt/wt%. The aminosilane compound can be at least one selected from the group consisting of 3- aminoethyltriethoxysilane, 3-aminopropyl triethoxysilane, n- phenylaminopropyltrimethoxysilane, trimethoxy-silylpropyldiethylene triamine, 3-(3- aminophenoxy) propyltrimethoxysilane, aminoethylaminomethyl phenyl trimethoxy silane, 2-aminoethyl-3-aminopropyl-tris-2-ethylhexoxysilane, n-amino-hexyl-amino propyltrimethoxysilane, and tris-aminopropyltrimethoxyethoxysilane.

In the present disclosure, the proportion of epoxy to silanated amine ratios is such that the amine blooming/blushing is controlled on one side and the cross-linking ability of the silanated amine is retained on the other. Further, in spite of the exothermic reaction between the epoxide and amine functional groups and generation of resultant hydroxyl moieties, the reactive nature of the amine and the silanol groups are retained, which is demonstrated by the adduct's ability to act as an efficient cross-linker of a hybrid organic-silicone binder system. The silanated amine cross-linker works by both reactive functionalities namely amine and silanol when the hybrid binder has both epoxy and silanol functionalities. In another aspect of the present disclosure, there is provided a process for preparation of the stable conjugate aminosilane adduct. The process comprises reacting either at least one epoxy compound or at least one acetoacetate compound with at least one aminosilane compound optionally in the presence of at least one catalyst to obtain the conjugate aminosilane adduct. The stable adduct can be epoxide-aminosilane adduct or acetoacetate-aminosilane adduct. In accordance with the present disclosure a solvent can be used in the preparation of adduct. The solvent can be selected from the group consisting of a non-polar solvent and a polar solvent and combinations thereof. In accordance with the present disclosure, the polar solvent is selected from the group consisting of polar protic solvents, polar aprotic solvents and combinations thereof, and the non-polar solvent is selected from the group consisting of aliphatic non-polar solvents and aromatic non-polar solvents and combinations thereof. Typically, the solvent can be selected from the group consisting of alcohols, esters, and ketones. Alcohols, such as ethanol, methanol, propanol, isopropanol etc; esters such as ethyl acetate, methyl acetate, propyl acetate, butyl acetate, benzyl acetate etc; and ketone such as acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), acetophenone, butanone, etc, can be used in the present disclosure.

The catalyst can be at least one selected from the group consisting of Lewis acid catalyst and Lewis base catalyst. Typically, the catalyst is dibutyl tin dilaurate. In still another aspect of the present disclosure, the stable conjugate aminosilane adduct of the present disclosure can be used as a binder to form a film on a substrate. The adduct binder forms a single component coating on the substrate with or without hardener. The hardener can be selected from the group consisting of an amino-resin hardener, an epoxy hardener, an epoxy-silane hardener, an epoxy-functional hardener, an epoxy-functional acrylic hardener, an epoxy-functional silane hardener, an epoxy-functional siloxane hardener, an epoxy- functional acrylic siloxane hardener and an epoxy functional acrylic polysiloxane hardener and combinations thereof. The hardener is typically used for baking/stoving or for ambient curing of the adduct. The substrate can be glass, wood, metal, or cementitious substrate. The so obtained film has a hardness greater than 0.5 kg, typically in the range of 2.5 kg to 4 kg and having thickness less than or equal to 100 micron, typically in the range of 10-20 microns. The stable conjugate aminosilane adduct can be epoxide-aminosilane adduct or acetoacetate-aminosilane adduct. The stable conjugate aminosilane adduct can be used as a crosslinker and can cure any epoxy binder, any epoxy-functional binder, any epoxy- functional acrylic binder, any epoxy-functional silane or siloxane binder, any epoxy- functional acrylic siloxane binder and any epoxy functional acrylic polysiloxane binder. The epoxy functional group of the binder link with the aminosilane of the adduct. More particularly siloxane of epoxy functional acrylic polysiloxane links with the silane of the adduct while coating on the substrate. The substrate can be selected from the group consisting of glass, metal, wood, cementitious substrate, and the like.

In an embodiment, curing of epoxy functional acrylic siloxane polymer using conjugate amino-silane with <10 wt% of aliphatic mono-epoxy compound exhibited blushing effect, however conjugate amino-silane with 25-40 wt% of aliphatic mono-epoxy compound did not exhibit the blushing effect. Conjugate amino-silane with >50-70 wt% of aliphatic mono- epoxy compound did not exhibit the blushing effect, however drying of the film is very slow i.e. >48 hr.

The present disclosure is further described in the light of the following laboratory experiments which are set forth for illustration purpose only, and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale, and the results obtained can be extrapolated to industrial scale. Experimental details:

Experiment 1: Preparation of conjugate aminosilane adduct in accordance with the present disclosure:

In a 100 ml round bottom flask lgm of Cardura E-10 (epoxy compound) was introduced, followed by addition of 1.7gm 3-amino propyl triethoxy silane in the presence of 0.05gm of dibutyl tin dilaurate (DBTDL) to obtain a reaction mixture. 1 % solution of DBTDL in o- xylene was used as the catalyst. The reaction mixture was stirred at 30 °C for 50 hours to obtain an adduct of Cardura E-10 and 3-amino propyl triethoxy silane (adduct 1). The amine equivalent weight of the adduct was found to be 250-300 and the viscosity (in cps) was found to be 80-150.

The amine value was used to calculate the amine equivalent weight by the following formula: 56.1X1000 / amine value = Amine equivalent weight (AEW).

Experiment 2: Preparation of conjugate aminosilane adduct in accordance with the present disclosure: Similar to experiment 1, different conjugate aminosilane adducts were prepared. Table- 1 summarizes the epoxy compound and the aminosilane used to prepare different adducts, along with the quantity used.

Table-1: Epoxide-aminosilane adduct

Experiment 3: Preparation of conjugate aminosilane adducts in accordance with the present disclosure:

Similar to experiment 1, different conjugate aminosilane adducts were prepared. Table-2 summarizes the acetoacetate compound and the aminosilane used to prepare different adducts, along with the quantity used.

Table-2: Acetoacetate-aminosilane adduct

Experiment 4: Adduct acts as a crosslinker in accordance with the present disclosure:

The adduct obtained in experiments 1 to 3 were used along with epoxy functional acrylic polysiloxane. The amount of adduct and other ingredients used are summarized in Table-3.

Table -3

The binder used in experiment 4 was epoxy functional acrylic polysiloxane.

From table 3, it can be seen that the drying time is reduced with catalyst, however hard film is achieved with more drying time which overcomes the issues of blushing. The presence of catalyst improves the drying time slightly and the effect can be increased with increasing catalyst concentration. TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE

The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a stable conjugate aminosilane adduct. The adduct can be used as a binder for coating a substrate that has a longer pot life, does not require long induction time before application, and shows less blushing in the coating. The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A stable conjugate aminosilane adduct comprising:

a. at least one epoxy compound or at least one acetoacetate compound; and b. at least one aminosilane compound, wherein said adduct has an amine value in the range of 90 mgKOH/g to 250 mgKOH/g and a viscosity in the range of 30 cps to 350 cps.

2. The adduct as claimed in claim 1, wherein said viscosity of said adduct is stable and increases by a maximum of 10% by accelerated stability test.

3. The adduct as claimed in claim 2, wherein said viscosity of said adduct is stable and increases by 7% by accelerated stability test.

4. The adduct as claimed in claim 1, wherein said epoxy compound is at least one selected from the group consisting of a monoepoxy compound and a polyepoxy compound.

5. The adduct as claimed in claim 4, wherein the proportion of said monoepoxy compound to said amino silane compound is in the range of 3:97 to 70:30 wt/wt%.

6. The adduct as claimed in claim 4, wherein the proportion of said polyepoxy compound to said amino silane compound is in the range of 3:97 to 40:60 wt/wt%.

7. The adduct as claimed in claim 4, wherein said monoepoxy compound is at least one selected from the group consisting of Phenyl glycidyl ether, glycidyl ester of Versatic Acid and Glycidyl neodecanoate

8. The adduct as claimed in claim 4, wherein said polyepoxy compound is at least one selected from the group consisting of epoxy novolac resin, epoxy solvent cut resin, liquid epoxy resin based on bisphenol-A, epoxy phenol novolac resin having functionality 3.6, bisphenol F type epoxy, epoxy resin of hydrogenated bisphenol A, and bisphenol A/F epoxy resin with monofunctional reactive diluent.

9. The adduct as claimed in claim 1, wherein said acetoacetate compound is at least one selected from the group consisting of ethyl acetoacetate, methyl acetoacetate, propyl acetoacetate, butyl acetoacetate, tertiary butyl acetoacetate, cyclohexyl acetoacetate and phenyl acetoacetate, acetoacetate functional monomer and acetoacetate functional polymer.

10. The adduct as claimed in claim 1, wherein the proportion of said acetoacetate compound to said amino silane compound is in the range of 3:97 to 50:50 wt/wt .

11. The adduct as claimed in claim 1, wherein said amino silane compound is at least one selected from the group consisting of 3-aminoethyltriethoxysilane, 3- aminopropyl triethoxysilane, n-phenylaminopropyltrimethoxysilane, trimethoxy- silylpropyldiethylene triamine, 3-(3-aminophenoxy)propyltrimethoxysilane, aminoethylaminomethylphenyl trimethoxysilane, 2-aminoethyl-3-aminopropyl- tris-2-ethylhexoxysilane, n-amino-hexyl-amino propyltrimethoxysilane, and tris- aminopropyltrimethoxyethoxysilane.

12. Use of the adduct as claimed in claims 1 to 11 as a crosslinker.

13. The use of the adduct as a crosslinker as claimed in claim 12 for curing at least one compound selected from the group consisting of an epoxy binder, an epoxy- functional binder, an epoxy-functional acrylic binder, an epoxy-functional silane, an epoxy-functional siloxane binder, an epoxy-functional acrylic siloxane binder and an epoxy functional acrylic polysiloxane binder and combinations thereof.

14. Use of the adduct as claimed in claims 1 to 11 as a binder for coating a substrate.

15. The adduct as claimed in claim 14, wherein said adduct is stored in a solvent, prior to use.

16. The adduct as claimed in claim 15, wherein said solvent is selected from the group consisting of non-polar solvent, polar solvent and combinations thereof.

17. The adduct as claimed claim 15, wherein said solvent is at least one nonpolar solvent selected from the group consisting of aliphatic non-polar solvent, aromatic non-polar solvents and combinations thereof.

18. The adduct as claimed claim 15, wherein said solvent is a polar solvent selected from the group consisting of protic polar solvent, aprotic polar solvents and combinations thereof.

19. The adduct as claimed claim 18, wherein said protic polar solvents is selected from the group consisting of alcohols, glycols, glycol monoethers and combinations thereof.

20. The adduct as claimed claim 18, wherein said aprotic polar solvent is selected from the group consisting of esters, ketones, ethers, glycol ethers and combinations thereof.

21. The adduct as claimed in any one of the preceding claims for use as a binder for coating a substrate, wherein said coating forms a film on said substrate, having hardness greater than 0.5 kg, typically in the range of 2.5 kg to 4 kg.

22. The adduct as claimed in claim 21 which forms a single component coating on said substrate.

23. The adduct as claimed in claim 21, wherein the adduct is used as a binder along with a hardener.

24. The adduct as claimed in claim 23, wherein said hardener is a compound selected from the group consisting of an amino resin hardener, an epoxy hardener, an epoxy-functional hardener, an epoxy-functional acrylic hardener, an epoxy- functional silane hardener, an epoxy-functional siloxane hardener, an epoxy- functional acrylic siloxane hardener and an epoxy functional acrylic polysiloxane hardener and combinations thereof.

25. The adduct as claimed in claims 21 to 24, wherein said substrate is glass, wood, metal or cementitious substrate.

26. A process for preparing a stable conjugate aminosilane adduct, said process comprising reacting at least one epoxy compound or at least one acetoacetate compound with at least one aminosilane, optionally in the presence of at least one catalyst to obtain an epoxide-aminosilane adduct or an acetoacetate-aminosilane adduct, wherein said adduct is characterized by amine value in the range of 90 mgKOH/g to 250 mgKOH/g and a viscosity in the range of 30 cps to 350 cps.

27. The process as claimed in claim 26, wherein at least one solvent is used in the preparation of said adduct.

28. The process as claimed in claim 27, wherein said solvent is selected from the group consisting of non-polar solvent, polar solvent, and combinations thereof, preferably from the group consisting of alcohols, esters, and ketones.

29. The process as claimed in claim 26, wherein the amount of said catalyst is in the range of 0.01 - 0.1 wt% , preferably 0.02 - 0.5 wt , more preferably 0.05 - 0.1 wt , of said aminosilane compound.

30. The process as claimed in claim 26, wherein said catalyst is Lewis acid catalyst.

31. The process as claimed in claim 30, wherein said catalyst is dibutyl tin dilaurate.