Claims:WE CLAIM
1. A water based binder composition comprising:
a. a matured slaked lime in an amount in the range of 30 to 80 wt% of the total amount of the binder composition;
b. calcium caseinate in an amount in the range of 4 to 10 wt% of the total amount of the binder composition; and
c. a first additive in an amount in the range of 0.1 to 10 wt% of the total amount of the binder composition.
2. The binder composition as claimed in claim 1, wherein the matured slaked lime has Hydraulicity Index in the range of 0.001 to 0.01.
3. The binder composition as claimed in claim 1, wherein the first additive is selected from the group consisting of a defoamer, a thickener and a surfactant.
4. The binder composition as claimed in claim 3, wherein the defoamer is present in an amount in the range of 0.1 to 1.0 wt% of the total amount of the binder composition.
5. The binder composition as claimed in claim 3, wherein the thickener is present in an amount in the range of 1.0 to 5.0 wt% of the total amount of the binder composition.
6. The binder composition as claimed in claim 3, wherein the surfactant is present in an amount in the range of 1.0 to 5.0 wt% of the total amount of the binder composition.
7. The binder composition as claimed in claim 3, wherein the defoamer is a substituted paraffin hydrocarbon.
8. The binder composition as claimed in claim 3, wherein the surfactant is selected from sugar alcohol and poly alkoxylate.
9. The binder composition as claimed in claim 3, wherein the thickener is selected from cellulose and derivatives thereof.
10. The process for preparation of the binder composition as claimed in claim 1, wherein the process comprising the following steps:
a. roasting lime at a temperature in the range of 900 to 1200 °C to obtain a roasted lime; and
b. slaking the roasted lime with water to obtain a slaked lime;
c. separately, mixing a first additive and casein to obtain a casein mixture;
d. stabilizing the slaked lime by adding the casein mixture at a temperature in the range of 20 to 40 °C to obtain a stabilized slaked lime comprising calcium caseinate;
e. maturing the stabilized slaked lime over a time period in the range of 7 to 180 days to obtain the binder composition;
wherein Hydraulicity Index of the slaked lime is in the range of 0.001 to 0.01.
11. The process as clamed in claim 10, wherein the step of maturing the slaked lime is carried out prior to the step of stabilization of the slaked lime with the casein mixture.
12. The process as clamed in claim 10, wherein the mole ratio of the slaked lime to casein is in the range of 1: 2 to 1: 5.
13. A water based coating composition comprising:
a. a water based binder composition as claimed in claim 1 in an amount in the range of 30.0 to 50.0 wt% of the total amount of the coating composition;
b. an extender in an amount in the range of 40.0 to 60.0 wt% of the total amount of the coating composition; and
c. a second additive in an amount in the range of 1.0 to 5.0 wt% of the total amount of the coating composition.
14. The coating composition as claimed in claim 13, wherein the extender is selected from the group consisting of calcium carbonate, talc, clays, dolomite, silica and silicates.
15. The coating composition as claimed in claim 13, wherein the second additive is selected from the group consisting of thickener, plasticizer, and wetting agent.
16. A process for preparation of the water based coating composition as claimed in claim 13, the process comprising the following steps:
i. obtaining a binder composition as claimed in claim 10;
ii. separately, mixing at least one second additive and an extender to obtain a paste;
iii. adding the binder composition to the paste to obtain a suspension; and
iv. curing the suspension for a time period in the range of 20 to 30 days to obtain the water based coating composition.
Dated this 24th Day of September, 2019

_______________________________
MOHAN DEWAN, IN/PA - 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant
, Description:
FIELD
The present disclosure relates to a binder composition, preferably a water based binder composition and a process for preparation thereof.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used to indicate otherwise.
Slaking the lime refers to the process of hydrating the lime (calcium oxide) to produce calcium hydroxide.
Maturing the lime refers to the step of allowing the slaked lime to condense and slowly changes from a liquid state to a thick paste state.
Breathability of the coating composition refers to ability of the coating composition to allow easy flow of air and water through the surface, to avoid trapping of moisture or dampness.
Hydraulicity of lime refers to the property of lime to harden in contact with water. Hydraulicity index of lime is calculated by formula given below:
Hydraulicity index = (%Al2O3+%Fe2O3+%SiO2) / (%CaO+%MgO).
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The conventional coatings are composed of the materials which are of synthetic nature. Most of these synthetic materials adds to marine and air pollution, as degradation of these materials is very slow process.
To overcome this drawback, the coatings based on natural components were considered. However, the conventional coatings based on natural components have very short wet shelf-life and are also associated with complexities of use. Therefore, these conventional coatings have limited scope.
Further, most coating compositions also contain synthetic solvents and ingredients that emits volatile organic compounds (VOCs) to the environment. These VOCs are accused of causing serious pathological conditions in humans. Moreover, once applied, these coatings forms plastic like film on the wall, which hinders the passage of water in either liquid or vapour form resulting in dampness. The damp conditions give rise to various physiological illnesses like allergic reactions, asthma, sick home syndrome and the like.
There is, therefore, felt a need for the development of a composition that mitigates the drawbacks mentioned herein above.
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 water based binder composition comprising natural components.
Another object of the present disclosure is to provide a process for preparation of the water based binder composition.
Still another object of the present disclosure is to provide a water based coating composition.
Yet another object of the present disclosure is to provide a process for preparation of the water based coating composition.
Yet another object of the present disclosure is to provide a composition having longer shelf life, low VOC, high breathability and anti-bacterial activity.
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 water based binder composition and a process for preparation thereof. The binder composition comprises a matured slaked lime in an amount in the range of 30 to 80 wt% of the total amount of the binder composition; calcium caseinate in an amount in the range of 4 to 10 wt% of the total amount of the binder composition; and a first additive in an amount in the range of 0.1 to 10 wt% of the total amount of the binder composition.
The process for the preparation of the binder composition comprises roasting a lime to obtain a roasted lime. The roasted lime is slaked with water to obtain a slaked lime. Separately, casein is mixed with a first additive to obtain a casein mixture. The slaked lime is stabilized by addition of the casein mixture to obtain a stabilized slaked lime. The stabilized slaked lime is matured for a period in the range of 7 to 180 days to obtain a binder composition. Optionally, the slaked lime is matured for a at least 7 days prior to the step of stabilization with the casein mixture.
The present disclosure further relates to a water based coating composition and a process for preparation thereof. The coating composition comprises a water based binder composition in an amount in the range of 30.0 to 50.0 wt% of the total amount of the coating composition; an extender in an amount in the range of 40.0 to 60.0 wt% of the total amount of the coating composition; and a second additive in an amount in the range of 1.0 to 5.0 wt% of the total amount of the coating composition.
The process to prepare the coating composition involves mixing an extender and a second additive to obtain a paste. The binder composition is then added to the paste to obtain a suspension. The suspension is cured for a time period in the range of 20 to 30 days to obtain the water based coting composition.
The composition of the present disclosure has more than 95% natural components. Further, the composition is characterized by longer shelf life, low VOC, high breathability and anti-bacterial activity.
DETAILED DESCRIPTION
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.
The conventional coatings are composed of materials which are of synthetic nature. Most of these synthetic materials adds to marine and air pollution as degradation of these chemicals is a very slow process.
To overcome this drawback, the present disclosure provides a water based binder composition having natural components and a process for its preparation. The present disclosure further provides a water based coating composition and a process for its preparation.
In the first aspect, the present disclosure provides a water based binder composition comprising a matured slaked lime in an amount in the range of 30 to 80 wt% of the total amount of the binder composition; calcium caseinate in an amount in the range of 4 to 10 wt% of the total amount of the binder composition; and a first additive in an amount in the range of 0.1 to 10 wt% of the total amount of the binder composition.
In accordance with the present disclosure, the matured slaked lime has Hydraulicity Index in the range of 0.001 to 0.01, preferably 0.007.
The first additive is selected from the group consisting of a defoamer, a thickener and a surfactant.
The defoamer is selected from the group consisting of substituted paraffin hydrocarbons, paraffin silicone, substituted polysilicones and polysiloxanes. In an exemplary embodiment, the defoamer is dewaxed heavy paraffin. The defoamer is present in an amount in the range of 0.1 to 1.0%. In an exemplary embodiment, the defoamer is present in an amount of 0.5 wt%.
The surfactant is selected from saccharides, carboxylates, sulphonates, alkoxylates, phosphonates. In an exemplary embodiment, the surfactant is a combination of sugar alcohol and poly alkoxylate. The surfactant is present in an amount in the range of 1.0 to 5.0%. In an exemplary embodiment, the surfactant is present in an amount of 2.0 wt%.
The thickener is selected from cellulose and derivatives thereof. In an exemplary embodiment, the thickener is hydroxyl ethyl cellulose. The thickener is present in an amount in the range of 1.0 to 5.0%. In an exemplary embodiment, the thickener is present in an amount of 2.5 wt%.
In the second aspect, the present disclosure provides a process for preparation of the binder composition. The process is described in detail herein below:
In the first step, lime is roasted at a temperature in the range of 900 to 1200 °C to obtain a roasted lime. The roasted lime is then slaked with water to obtain a slaked lime. The step of slaking of lime removes the impurities present in lime.
Optionally, the slaked lime is matured for a time period in the range of 7 to 15 days to obtained a matured slaked lime.
Separately, casein and at least one first additive are mixed together to form a casein mixture.
The first additive is selected from a thickener, a deafoamer and a surfactant.
In accordance with the exemplary embodiment, casein is mixed with a defoamer and a surfactant to form the casein mixture. Casein has a tendency to stabilize a foam in the system. Therefore, to eliminate generation of the foam, casein is first mixed with defoamer.
The slaked lime is stabilized by reaction with casein at a temperature in the range of 20 to 35 °C to obtain a stabilized slaked lime. Typically, calcium present in lime reacts with casein present in the mixture to form an adduct, calcium caseinate.
The slaked lime is selected from non-matured slaked lime, matured slaked lime and hydrated slaked lime.
The mole ratio of slaked lime to casein is in the range of 1: 2 to 1: 5. In an exemplary embodiment, the mole ratio of slaked lime to casein is 1: 2.
In accordance with the present disclosure, the ratio of slaked lime to casein is maintained higher than that required for neutralization of casein. The part of the slaked lime, is reacted with casein to form calcium-caseinate, an adduct.
The stabilized slaked lime is matured for a time period in the range of 7 to 180 days to obtain the binder composition.
Typically, the Hydraulicity Index of the matured slaked lime is in the range of 0.001 to 0.01, preferably 0.007.
In the third aspect, the present disclosure provides a water based coating composition comprising the water based binder composition in an amount in the range of 30.0 to 50.0 wt% of the total amount of the coating composition; an extender in an amount in the range of 40.0 to 50.0 wt% of the total amount of the coating composition; and a second additive in an amount in the range of 1.0 to 5.0 wt% of the total amount of the coating composition.
The extender is selected from the group consisting of calcium carbonate, talc, clays, dolomite, silica and silicates. In an exemplary embodiment, the extender is a combination of calcium carbonate and magnesium carbonate. The amount of extender is in the range of 40 to 60 wt%. In an exemplary embodiment, the amount of extender is 50 wt%.
The second additive is selected from the group consisting of thickener, plasticizers, and wetting agent.
The plasticizer is selected from phathalates, terephthalates, epoxies, aliphatics. In an exemplary embodiment, the plasticizer is an aliphatic oil. The amount of plasticizer is in the range of 2 to 6 wt%. In an exemplary embodiment, the amount of plasticizer is 3 wt%.
The wetting agent is selected from glycerophospholipid which includes phosphatidylcholine, phosphatidylethanolamine, phosphate-idylinositol, phosphatidylserine, and phosphatidic acid. The amount of wetting agent is in the range of 0.2 to 0.45%. In an exemplary embodiment, the amount of wetting agent is 0.3 wt%.
In the fourth aspect, the present disclosure provides a process to prepare a water based coating composition. The process is described in detail herein below:
Initially, a second additive is mixed with an extender to form a paste.
The second additive is selected from a thickener, a deafoamer, a surfactant, a wetting agent, a plasticizer and a pigment.
The binder composition is then added to so obtained paste under continuous stirring to obtain a suspension.
The suspension is cured for a time period in the range of 20 to 30 days to obtain the water based coting composition.
The adduct, calcium caseinate plays a vital role in overall stabilization of the coating composition and provides binding to overcome the immediate chalking behavior observed in the lime based paints. It also allows easy and uniform deposition of the coating by the application tools thereby resulting in smoother and uniform finish.
The excess slaked lime in the coating composition renders in-can microbial resistance and cures to offer long-term durability.
The composition has more than 95% of ingredients which are either natural or of natural origin. The water based coating composition of the present disclosure is characterized by having a wet shelf-life of minimum 2 yrs. The composition is characterized by VOC of 3 gm/lit as per ASTM D 6886-18 and SD value of less than 0.01 m.
Due to high natural content and low VOC of the coating composition, it does not add to any air, soil and marine pollution during any phase of its life-cycle. Further, the composition has high breathability, which prevents condensation of moisture and dampness of the local environment. The coating also exhibits high anti-bacterial performance with more than 99% kill in 2 hrs as per JIS Z 2801. This property contributes to purification of interior environment adding value to living conditions.
The present disclosure provides an effective solution in the form of the coating composition that is non-toxic and sustainable yet offers novel properties like breathability and anti-microbial resistance.
The foregoing description of the embodiments has been provided for purposes of illustration and 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 industrial scale.
EXPERIMENTAL DETAILS
Experiment 1: Preparation of binder composition
Limestone or marble powder was roasted at 1000 °C to obtain a roasted lime. The roasted lime was then slaked with water to remove impurities to obtain a slaked lime.
The slaked lime was matured for a time period of 50 days and filtered through 150# sieve to obtain a matured slaked lime.
Separately, casein (20 wt%) having a protein content not less than 82% and not more than 86% was added to ethyl cellulose (1 wt%), dewaxed heavy paraffin (0.5 wt%) and D-Sorbitol (0.5 wt%) to obtain a mixture. The mixture was stirred 45 mins under a shear rate of 5 m/s of the cowl disc (high speed disperser) to achieve swelling of the protein.
Polyalkoxylate type surfactants (0.5 wt%) was added to the mixture, followed by addition of the slaked lime (40 wt%) under stirring for 20 min to obtain a stabilized slake lime.
The so obtained stabilized slaked lime was further matured for 40 days. The stabilized slaked lime was agitated by a cowl stirrer at a shear rate of 5-7 m/s tip speed with a schedule of 10-15 min/day. During the maturing process, more than 95% of the casein binded with calcium of lime to form calcium caseinate.
The mixture was filtered through 80 mesh sieve to obtain a binder composition.
The binder composition is characterized by having a viscosity of 60 KU measured by a Stormer Viscometer at 30±1C°and a solid content between 26-32% when subjected to 120°C for 1 hr.
Experiment 2: Preparation of binder composition using non-matured slaked lime.
Same experimental procedure as described hereinabove was followed, except non-matured slaked lime was used in the preparation of the binder composition. Non-matured slaked lime refers to slaked lime which is not matured prior to stabilization.
Experiment 3: Preparation of binder composition using hydrated lime.
Same experimental procedure as described hereinabove was followed, except hydrated lime was used in the preparation of the binder composition. Hydrated lime refers to quick lime mixed with water.
Experiment 4: Preparation of binder composition using matured slaked lime.
Same experimental procedure as described hereinabove was followed, except the amount of matured slaked lime was equal to the stoichiometric requirement of lime.
The binder compositions prepare in examples 1 to 5 were further used for the preparation of the water based coating composition.
Experiments 5-8: Preparation of the water based coating composition
General procedure:
Initially, hydroxyl ethyl cellulose (1.5 wt%, thickener), glycerophospholipid (0.3 wt%, wetting agent) were mixed to obtain a mixture. Calcium carbonate and Talc (50 wt%, extender) was added to the mixture, followed by addition of dehydrated castor oil (3 wt%) to obtain a paste. The paste had constituency between 240-280 Degrees of Penetration (DOP) in a Penetrometer at 30±1 °C.
To the so obtained paste was added the binder composition obtained in experiments 1 to 4 respectively to obtain a water based coating composition. The coating composition had a constituency of 340-360 DOP in a Penetrometer at 30±1°C.
The chemical composition of the water based coating composition are given below in table 1:
Table1: Chemical composition of the water based coating composition
Sr. No. Component Ex. 5 Ex. 6 Ex. 7 Ex. 8
1 Binder composition Ex. 1 Ex. 2 Ex. 3 Ex. 4
Lime Matured slaked lime Non-slaked lime Hydrated lime Matured slaked lime
Amount of lime 350 times of the Stoichiometric amount 350 times of the Stoichiometric amount 350 times of the Stoichiometric amount Stoichiometric amount
Calcium caseinate 5 wt% 5 wt% 5 wt% 5 wt%
Defoamer 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt%
Surfactant 1 wt% 1 wt% 1 wt% 1 wt%
Thickener 1 wt% 1 wt% 1 wt% 1 wt%
2 Wetting agent 0.3 wt% 0.3 wt% 0.3 wt% 0.3 wt%
3 Thickener 1.5 wt% 1.5 wt% 1.5 wt% 1.5 wt%
4 Plasticizer 3 wt% 3 wt% 3 wt% 3 wt%
5 Extender 50 wt% 50 wt% 50 wt% 50 wt%

The summary of the performance of the coating composition prepared in experiments 6-10 is given below:
Table 2:
Coating compositions Gelling of batch Microbial Resistance
(After 48 hours) Applicability and finish of the coating composition
Composition 5 No Gelling
Batch processed to completion Unaffected Acceptable
Composition 6 No Gelling
Batch processed to completion Unaffected Not acceptable
Composition 7 Gelling occurred
Batch cannot processed to completion Not tested Not tested
Composition 8 No Gelling
Batch processed to completion Microbial degradation
Emission of foul odour Not tested

From table 2, it is evident that the coating composition 7 comprising hydrated lime could not be processed to completion due to unmanageable processing viscosity, due to gelling.
Further, the coating compositions 8 comprising lower amounts of lime in the composition exhibited microbial degradation.
Furthermore, the coating composition 6 comprising non-matured slaked lime was failed to provide uniform of smooth coating.
However, the coating composition 5 in accordance with the present disclosure exhibited in-can microbial resistance, uniform and smooth application of coating and obviated gelling of the composition during processing.
TECHNICAL ADVANCEMENTS AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
• a water based binder composition:
- with more than 95% components being natural or of natural origin;
- having in-can microbial resistance; and
- capable of obviating chalking behavior of the lime based paints; and
• a water based coating composition having:
- more than 95% components being natural or of natural origin;
- longer shelf life;
- lower VOC; and
- high breathability.
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 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 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.