Claims:WE CLAIM:
1. A process for preparing 2-butoxyethyl chloroacetate, said process comprising the following steps:
i. reacting butyl cellosolve with mono chloro acetic acid in a predetermined molar ratio in the presence of a catalyst in a fluid medium to obtain a reaction mixture;
ii. heating said reaction mixture at a first predetermined temperature and simultaneously removing water to obtain a product mixture comprising 2-butoxyethyl chloroacetate, said fluid medium, unreacted mono chloro acetic acid and said catalyst;
iii. adding water to said product mixture to obtain a first biphasic mixture containing a first organic phase and a first aqueous phase, wherein said first aqueous phase comprises said unreacted mono chloro acetic acid and said catalyst and said first organic phase comprises 2-butoxyethyl chloroacetate and said fluid medium;
iv. separating said first aqueous phase from said first biphasic mixture to obtain said first organic phase comprising 2-butoxyethyl chloroacetate and said fluid medium;
v. washing said first organic phase with an aqueous base by maintaining a pH in the range of 6 to 9 to obtain a second biphasic mixture containing a second organic phase and a second aqueous phase followed by separating said second aqueous phase from said second biphasic mixture to obtain said second organic phase containing 2-butoxyethyl chloroacetate and said fluid medium; and
vi. vacuum distilling said second organic phase at a second predetermined temperature and at a predetermined pressure to recover said fluid medium, to obtain a residual mass containing 2-butoxyethyl chloroacetate.
2. The process as claimed in claim 1, wherein a small fraction of 2-butoxyethyl chloroacetate is distilled out along with said recovered fluid medium and wherein said recovered fluid medium along with said small fraction of 2-butoxyethyl chloroacetate are recycled to a next batch.
3. The process as claimed in claim 1, wherein said predetermined molar ratio of said butyl cellosolve to said mono chloro acetic acid is in the range of 1:1 to 1:1.5.
4. The process as claimed in claim 1, wherein said catalyst is selected from the group consisting of para toluene sulfonic acid (PTSA) and methane sulphonic acid.
5. The process as claimed in claim 1, wherein said catalyst is present in an amount in the range of 1 mole% to 2 mole % with respect to the amount of butyl cellosolve.
6. The process as claimed in claim 1, wherein said fluid medium is selected from the group consisting toluene, n-hexane, cyclohexane, benzene and chlorobenzene.
7. The process as claimed in claim 1, wherein said base is selected from the group consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide and potassium hydroxide.
8. The process as claimed in claim 1, wherein said first predetermined temperature is in the range of 50 °C to 120 °C and said second predetermined temperature is in the range of 100 °C to 130 °C.
9. The process as claimed in claim 1, wherein said predetermined pressure is in the range of 10 mmHg to 20 mmHg.
10. The process as claimed in claim 1, wherein a yield of 2-Butoxyethyl chloroacetate is in the range of 90 % to 99 % and a purity is in the range of 98 % to 99.9 %. , Description:FIELD
The present disclosure relates to a process for the preparation of 2-Butoxyethyl chloroacetate.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Triclopyr-butotyl is an organic compound in the pyridine group that is used as a systemic foliar herbicide and fungicide. Triclopyr-butotyl is used to control broadleaf weeds and also to control rust diseases on crops. The chemical name of triclopyr-butotyl is 2-[(3,5,6-trichloro-2-pyridinyl)oxy]acetic acid 2-butoxyethyl ester and has the following chemical structure:

Triclopyr-butotyl
2-Butoxyethyl chloroacetate is an important intermediate used for the preparation of Triclopyr-butotyl. Conventionally, the process of preparing 2-Butoxyethyl chloroacetate involves catalytic esterification of butyl cellosolve and mono chloro acetic acid by using mineral acid as a catalyst. However, various impurities/by-products are formed during the conventional processes. Further, the use of mineral acids on a large scale production/reaction is not convenient due to the corrosive nature of the mineral acids.
There is, therefore, felt a need to provide a process for preparing 2-Butoxyethyl chloroacetate that mitigates the aforestated drawbacks or at least provides a useful alternative.
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 process for the preparation of 2-Butoxyethyl chloroacetate.
Another object of the present disclosure is to provide a process for the preparation of 2-Butoxyethyl chloroacetate with high yield and high purity.
Yet another object of the present disclosure is to provide a process for the preparation of 2-Butoxyethyl chloroacetate that is environment friendly.
Still another object of the present disclosure is to provide a simple and cost-efficient process for the preparation of 2-Butoxyethyl chloroacetate.
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 process for the preparation of 2-Butoxyethyl chloroacetate. The process comprises reacting butyl cellosolve with mono chloro acetic acid in a predetermined molar ratio in the presence of a catalyst in a fluid medium to obtain a reaction mixture. The reaction mixture is heated at a first predetermined temperature and simultaneously, water is removed to obtain a product mixture comprising 2-butoxyethyl chloroacetate, fluid medium, unreacted mono chloro acetic acid and the catalyst. Further, water is added to the product mixture to obtain a first biphasic mixture comprising a first organic phase and a first aqueous phase, wherein the first aqueous phase comprises the unreacted mono chloro acetic acid and the catalyst and the first organic phase comprises 2-butoxyethyl chloroacetate and the fluid medium. The first aqueous phase comprising the unreacted mono chloro acetic acid and the catalyst is separated from the first biphasic mixture to obtain the first organic phase comprising 2-butoxyethyl chloroacetate and the fluid medium. The first organic phase is washed with an aqueous base to maintain a pH in the range of 6 to 9 to obtain a second biphasic mixture containing a second organic phase and a second aqueous phase followed by separating the second aqueous phase from the second biphasic mixture to obtain the second organic phase containing 2-butoxyethyl chloroacetate and the fluid medium. The second organic phase is vacuum distilled at a second predetermined temperature and at a predetermined pressure to recover the fluid medium, to obtain a residual mass containing 2-butoxyethyl chloroacetate. The unreacted mono chloro acetic acid, the fluid medium and the catalyst are recovered and recycled in the next batch.
DETAILED DESCRIPTION
The present disclosure relates to a process for the preparation of 2-Butoxyethyl chloroacetate.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Triclopyr-butotyl is a synthetic herbicide used to control both broadleaf and woody plants. Broadleaf weeds often controlled with Triclopyr-butotyl include nettles, docks, brambles, and woody plants. It affects actively growing plants by mimicking a specific type of plant growth hormone, known as an auxin. Plants rapidly take in Triclopyr-butotyl through leaves and roots and lead to plant death. After absorbing the herbicide, the plants die slowly i.e. within weeks.
2-Butoxyethyl chloroacetate is an important intermediate in the preparation of Triclopyr-butotyl. Conventionally, the process of preparing 2-Butoxyethyl chloroacetate involves catalytic esterification of butyl cellosolve and mono chloro acetic acid by using mineral acid as catalyst. However, various impurities/by-products are formed during the conventional processes. Further, the use of mineral acids on a large scale is not convenient due to the corrosive nature of the mineral acids.
The present disclosure provides a process for the preparation of 2-Butoxyethyl chloroacetate which is simple, provides 2-Butoxyethyl chloroacetate in high yield and high purity and is environment friendly.
The present disclosure provides a process for the preparation of 2-Butoxyethyl chloroacetate. 2-Butoxyethyl chloroacetate is represented below as Formula I.

Formula-I
Chemical formula: C8H15ClO3
Molar mass: 194.65
The process for the preparation of 2-Butoxyethyl chloroacetate comprises the following steps:
i. reacting butyl cellosolve with mono chloro acetic acid in a predetermined molar ratio in the presence of a catalyst in a fluid medium to obtain a reaction mixture;
ii. heating the reaction mixture at a first predetermined temperature and simultaneously removing water to obtain a product mixture comprising 2-butoxyethyl chloroacetate, the fluid medium, unreacted mono chloro acetic acid and the catalyst;
iii. adding water to the product mixture to obtain a first biphasic mixture containing a first organic phase and a first aqueous phase, wherein the first aqueous phase comprises the unreacted mono chloro acetic acid and the catalyst and the first organic phase comprises 2-butoxyethyl chloroacetate and the fluid medium;
iv. separating the first aqueous phase from the first biphasic mixture to obtain the first organic phase comprising 2-butoxyethyl chloroacetate and the fluid medium;
v. washing the first organic phase with an aqueous base by maintaining a pH in the range of 6 to 9 to obtain a second biphasic mixture containing a second organic phase and a second aqueous phase followed by separating the second aqueous phase from the second biphasic mixture to obtain the second organic phase containing 2-butoxyethyl chloroacetate and the fluid medium; and
vi. vacuum distilling the second organic phase at a second predetermined temperature and at a predetermined pressure to recover the fluid medium, to obtain a residual mass containing 2-butoxyethyl chloroacetate.
The process is described in detail herein below:
In a first step, butyl cellosolve is reacted with mono chloro acetic acid in a predetermined molar ratio in the presence of a catalyst in a fluid medium to obtain a reaction mixture.
In an embodiment of the present disclosure, the predetermined molar ratio of the butyl cellosolve to the mono chloro acetic acid is in the range of 1:1 to 1:1.5. In an exemplary embodiment of the present disclosure, the molar ratio of the butyl cellosolve to the mono chloro acetic acid is 1:1.15.
The catalyst is selected from the group consisting of para toluene sulfonic acid (PTSA) and methane sulphonic acid. In an exemplary embodiment of the present disclosure, the catalyst is para toluene sulfonic acid (PTSA).
The catalyst is present in an amount in the range of 1 mole% to 2 mole% with respect to the amount of butyl cellosolve. In an exemplary embodiment of the present disclosure, the amount of the catalyst is 1.1 mole% with respect to the amount of butyl cellosolve.
The fluid medium is selected from the group consisting of toluene, n-hexane, cyclohexane, benzene and chlorobenzene. In an exemplary embodiment of the present disclosure, the fluid medium is toluene. In another exemplary embodiment of the present disclosure, the fluid medium is hexane.
In a second step, the reaction mixture is heated at a first predetermined temperature and simultaneously water is removed to obtain a product mixture comprising 2-butoxyethyl chloroacetate, the fluid medium, unreacted mono chloro acetic acid and the catalyst.
The first predetermined temperature is in the range of 50 °C to 130 °C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 86 °C. In another exemplary embodiment of the present disclosure, the first predetermined temperature is 65 °C.
In an embodiment of the present disclosure, the simultaneous removal of water from the reaction mixture is done by azeotropic distillation.
In a third step, water is added to the product mixture to obtain a first biphasic mixture comprising a first organic phase and a first aqueous phase, wherein the first aqueous phase comprises the unreacted mono chloro acetic acid and the catalyst and the first organic phase comprises 2-butoxyethyl chloroacetate and the fluid medium.
The advantage of adding water to the product mixture in this step is that the majority of the unreacted mono chloro acetic acid and the catalyst get dissolved in water and get separated from the product mixture and can be recycled in the next batch. Therefore, a less amount of base will be required in the next step for washing off the traces of acids present in the first organic phase.
In a fourth step, the first aqueous phase comprising the unreacted mono chloro acetic acid and the catalyst is separated from the first biphasic mixture to obtain the first organic phase comprising 2-butoxyethyl chloroacetate and the fluid medium.
In accordance with an embodiment of the present disclosure, the first aqueous phase containing the catalyst and the unreacted mono chloro acetic acid are recycled and used in the next batch, thus, making the process economical and environment friendly.
In a fifth step, the first organic phase is washed with an aqueous base by maintaining a pH in the range of 6 to 9, to obtain a second biphasic mixture comprising a second organic phase and a second aqueous phase followed by separating the second aqueous phase from the second biphasic mixture to obtain the second organic phase containing 2-butoxyethyl chloroacetate and the fluid medium.
The aqueous base neutralizes the traces of acids present in the first organic phase to form salts. Thus, the second aqueous phase comprises the traces of mono chloro acetic acid salt and traces of catalyst salt which is separated from the second biphasic mixture. Thus, the acid impurities are completely removed from the second organic phase containing 2-butoxyethyl chloroacetate and the fluid medium.
The base is selected from the group consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide and potassium hydroxide. In an exemplary embodiment of the present disclosure, the base is sodium carbonate.
In an embodiment of the present disclosure, the pH is in the range of 7 to 8. In an exemplary embodiment of the present disclosure, the pH is 7.5.
In a sixth step, the second organic phase is vacuum distilled at a second predetermined temperature and at a predetermined pressure to recover the fluid medium, to obtain a residual mass containing 2-butoxyethyl chloroacetate
The second pre-determined temperature is in the range of 100 °C to 130 °C. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 105 °C. In another exemplary embodiment of the present disclosure, the second predetermined temperature is 110 °C.
The pre-determined pressure is in the range of 10 mmHg to 20 mmHg. In an exemplary embodiment of the present disclosure, the pre-determined pressure is 15 mmHg.
In accordance with an embodiment of the present disclosure, during the vacuum distillation of the organic phase, traces of 2-Butoxy chloroacetate is also distilled out along with the fluid medium.
The yield of 2-butoxyethyl chloroacetate obtained by the process of the present disclosure is in the range of 90 mole% to 99 mole%. The purity of 2-butoxyethyl chloroacetate obtained by the process of the present disclosure is 98.0 % to 99.9 %.
The recovered fluid medium along with the traces of 2-Butoxy chloroacetate are recycled and used in the next batch making the process economical and environment friendly.
The process of the present disclosure is simple, economical, environment friendly and suitable for industrial applications. The unreacted starting materials, fluid medium and catalysts are recovered and recycled in the next batch making the process of the present disclosure economical and environment friendly.
The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following 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 the industrial scale.
EXPERIMENTAL DETAILS
Example 1: Preparation of 2-butoxyethyl chloroacetate using toluene as a fluid medium in accordance with the present disclosure
In a 4 neck round bottom flask with Dean and Stark apparatus, double coil condenser, overhead stirrer and reaction temperature indicator, 118.0 g of butyl cellosolve and 113.4 g of mono chloro acetic acid were charged and reacted in the presence of 2.0 g of para toluene sulfonic acid (PTSA) in 100 ml toluene to obtain a reaction mixture. The reaction mixture was heated at 86 °C and simultaneously water was removed through the Dean and Stark system to obtain a product mixture comprising 2-butoxyethyl chloroacetate, toluene, unreacted mono chloro acetic acid and para toluene sulfonic acid. After complete removal of water (18ml), the product mixture was cooled to 20 °C followed by adding 10 ml of water to obtain a first biphasic mixture comprising a first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and a first aqueous phase. The first aqueous phase comprising the unreacted mono chloro acetic acid and the catalyst was separated from the first biphasic mixture and recycled in next batch. The first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and traces of acid impurity was subjected to washing with 75 ml of an aqueous solution of sodium carbonate (5 %w/w) to maintain a pH of 7.5 to obtain a second biphasic mixture comprising a second organic phase and a second aqueous phase. The second aqueous phase comprising the traces of mono chloro acetic acid salt and PTSA salt was separated from the second biphasic mixture to obtain the second organic phase comprising 2-butoxyethyl chloroacetate and toluene. The second organic phase was vacuum distilled at 105 °C at a pressure of 15 mmHg to recover toluene, to obtain a residual mass containing 2-butoxyethyl chloroacetate. Small fraction of 2-butoxyethyl chloroacetate was also distilled out along with toluene. The recovered toluene along with the traces of 2-Butoxy chloroacetate was recycled and used in the next batch.
The purity of 2-butoxyethyl chloroacetate was 99.0 % and the yield was 96.0 mole %.
Example 2: Preparation of 2-butoxyethyl chloroacetate by using the recovered fluid of Example 1
In a 4 neck round bottom flask with Dean and Stark apparatus, double coil condenser, overhead stirrer and reaction temperature indicator, 118.0 g of butyl cellosolve and 108.7 g of mono chloro acetic acid were charged and reacted in the presence of 2.0 g of para toluene sulfonic acid and recovered toluene along with the traces of 2-butoxyethyl chloroacetate of example 1 were added to obtain a reaction mixture. The reaction mixture was heated at 86 °C and simultaneously water was removed through the Dean and Stark system to obtain a product mixture comprising 2-butoxyethyl chloroacetate, toluene, unreacted mono chloro acetic acid and para toluene sulfonic acid. After complete removal of water (18ml), the product mixture was cooled to 20 °C followed by adding 10 ml of water to obtain a first biphasic mixture comprising a first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and a first aqueous phase. The first aqueous phase comprising the unreacted mono chloro acetic acid and the catalyst was separated from the first biphasic mixture and recycled in next batch. The first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and traces of acid impurity was subjected to washing with 75 ml of an aqueous solution of sodium carbonate (5 %w/w) to maintain a pH of 7.5 to obtain a second biphasic mixture comprising a second organic phase and a second aqueous phase. The second aqueous phase comprising the traces of mono chloro acetic acid salt and PTSA salt was separated from the second biphasic mixture to obtain the second organic phase comprising 2-butoxyethyl chloroacetate and toluene. The second organic phase was vacuum distilled at 108 °C at a pressure of 15 mmHg to recover toluene, to obtain a residual mass containing 2-butoxyethyl chloroacetate. Small fraction of 2-butoxyethyl chloroacetate was also distilled out along with toluene. The recovered toluene along with the traces of 2-Butoxy chloroacetate was recycled and used in the next batch.
The purity of 2-butoxyethyl chloroacetate was 99.05 % and the yield was 97.0 mole %.
Example 3: Preparation of 2-butoxyethyl chloroacetate by using the recovered fluid medium of Example 2
In a 4 neck round bottom flask with Dean and Stark apparatus, double coil condenser, overhead stirrer and reaction temperature indicator, 118.0 g of butyl cellosolve and 108.7 g of mono chloro acetic acid were charged and reacted in the presence of 2.0 g of para toluene sulfonic acid and the recovered toluene along with the traces of 2-butoxyethyl chloroacetate of example 2 were added to obtain a reaction mixture. The reaction mixture was heated at 86 °C and simultaneously water was removed through the Dean and Stark system to obtain a product mixture comprising 2-butoxyethyl chloroacetate, toluene, unreacted mono chloro acetic acid and para toluene sulfonic acid. After complete removal of water (18ml), the product mixture was cooled to 20 °C followed by 10 ml of water to obtain a first biphasic mixture comprising a first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and a first aqueous phase. The first aqueous phase comprising the unreacted mono chloro acetic acid and the catalyst was separated from the first biphasic mixture and recycled in next batch. The first organic phase comprising 2-butoxyethyl chloroacetate along with toluene and traces of acid impurity was subjected to washing with 75 ml of an aqueous solution of sodium carbonate (5 %w/w) to maintain a pH of 7.5 to obtain a second biphasic mixture comprising a second organic phase and a second aqueous phase. The second aqueous phase comprising the traces of mono chloro acetic acid salt and PTSA salt was separated from the second biphasic mixture to obtain the second organic phase comprising 2-butoxyethyl chloroacetate and toluene. The organic phase was vacuum distilled at 108 °C at a pressure of 15 mmHg to recover toluene and to obtain a residual mass containing 2-butoxyethyl chloroacetate. Small fraction of 2-butoxyethyl chloroacetate was also distilled out along with toluene. The recovered toluene along with the traces of 2-Butoxy chloroacetate was recycled and used in the next batch.
The purity of 2-butoxyethyl chloroacetate was 99.5 % and the yield was 97.5 mole %.
Example 4: Preparation of 2-butoxyethyl chloroacetate using n-hexane as a fluid medium in accordance with the present disclosure
The same procedure of Example 1 was followed except that 100 ml of n-hexane was used instead of toluene to obtain 2-butoxyethyl chloroacetate.
The purity of 2-butoxyethyl chloroacetate was 99.5 % and the yield was 97.0 mole %.
Example 5: Preparation of 2-butoxyethyl chloroacetate by using the recovered fluid medium and recovered catalyst of Example 4
The same procedure of Example 1 was followed except that the recovered n-hexane along with the traces of 2-butoxyethyl chloroacetate of example 4 was used instead of toluene to obtain 2-butoxyethyl chloroacetate.
The purity of 2-butoxyethyl chloroacetate was 99.4 % and the yield was 97.2 mole %.
Example 6: Preparation of 2-butoxyethyl chloroacetate by using the recovered fluid medium and recovered catalyst of Example 5
The same procedure of Example 1 was followed except that the recovered n-hexane along with the traces of 2-butoxyethyl chloroacetate of example 5 was used instead of toluene to obtain 2-butoxyethyl chloroacetate.
The purity of 2-butoxyethyl chloroacetate was 99.6 % and the yield was 97.0 mole %.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a process for the preparation of 2-butoxyethyl chloroacetate, that:
? is environment friendly as solvents, reactants and catalyst are recycled;
? is simple, efficient, and economical; and
? provides 2-butoxyethyl chloroacetate in high yield and high purity.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/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.
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 invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
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 given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment 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.