DESC:
FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)


Title of Invention:
PROTEIN BASED BINDERS AND WOOD AND AGRICULTURAL WASTE BASED PRODUCTS THEREOF

Applicant
Pidilite Industries Limited
A Company Incorporated in India under The Companies Act, 1956
Regent Chambers, 7th Floor,
Jamnalal Bajaj Marg, 208, Nariman Point,
Mumbai – 400021,
Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority to Indian Provisional Application No. 3712/MUM/2013, filed on November 26th, 2013, the entirety of which is hereby incorporated by reference.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to preparation of binders and particularly to preparation of protein based binders, and application of protein based binders to manufacture wood and agricultural waste based products thereof.

BACKGROUND
[003] Formaldehyde based binders are being used since long time to achieve better strength and water resistance properties. The formaldehyde based binders are being used in interior as well as exterior applications. However use of the formaldehyde based binders leads to continuous emission of formaldehyde in the air which is hazardous to community health. Considering community health aspect, use of the formaldehyde based binders is being prohibited in many countries. Hence demand for formaldehyde free binders is increased.
[004] Formaldehyde free binders manufactured from protein source in the prior art suffers with drawbacks such as poor water resistance, high viscosity and restricted use to interior application. Further, the formaldehyde free protein based binders also showed limited shelf life. Recent developments in the field of soy protein binders proposed use of variety of denaturing agents to denature the soy protein, however the soy protein binders are still suffering from the problem of high viscosity. Further, there are a variety of curing agents proposed in the art to increase the strength of the binders and improve water resistance. Although the curing agents are used widely, the protein based binders are still facing with poor water resistance and high viscosity. Further, the soy protein binders produced by conventional processes are expensive.
SUMMARY
[005] This summary is provided to introduce aspects related to processes for preparing a protein based binder and a wood based product, and compositions of a protein based binder. The aspects are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[006] In one implementation, a process 100 for preparing a protein based binder is disclosed. The process comprises denaturing of a proteinaceous material by cooking the proteinaceous material in presence of water, an alkaline agent, a urea and a polyphenolic compound, at a temperature range of 40 to 150 deg C to prepare the protein based binder. The proteinaceous material is a soy protein and the soy protein is in form of soy flour, a soy concentrate, or a soy protein isolate, obtained from soy beans. The polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).
[007] In another implementation, a process 200 for preparing a protein based binder is disclosed. The process comprises carboxylating a proteinaceous material by esterification of the proteinaceous material with a carboxylating agent to produce a carboxylated proteinaceous material. The process 200 further comprises denaturing of the carboxylated proteinaceous material by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, a polyphenolic compound, and a natural resin such as a shellac, at a temperature range of 40 to 150 deg C to prepare the protein based binder. The proteinaceous material is a soy protein and the soy protein is in form of soy flour, a soy concentrate, or a soy protein isolate, obtained from soy beans. The polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).
[008] In another implementation, a composition 500 of a protein based binder is described. The composition 500 of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a range of 10 to 17 weight parts; c) an alkaline agent in a range of 1 to 4 weight parts; d) urea in a range of 8 to 12 weight parts, and e) a polyphenolic compound in a range of 2 to 8 weight parts.
[009] In another implementation, a composition 600 of a protein based binder is described. The composition 600 of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a rage of 14 to 50 weight parts; c) a carboxylating agent in a range of 2 to 4 weight parts; d) an alkaline agent in a range of 1 to 4 weight parts; and e) a polyphenolic compound in a range of 2 to 8 weight parts and f) a natural resin such as shellac in a range of 2 to 5 weight parts.
[0010] In another implementation, a method 300 for making a wood based product is disclosed. The method comprises mixing a protein based binder and a cross linking agent to prepare a mixture. The protein based binder is prepared by a process comprising denaturing of a proteinaceous material by cooking the proteinaceous material in presence of water, an alkaline agent, a urea and a polyphenolic compound, at a temperature range of 40 to 150 deg C to prepare the protein based binder. The method 300 further comprises applying the mixture to wood material or agricultural waste or a combination thereof to produce the wood based product.
[0011] In another implementation, a method 400 for making a wood based product is disclosed. The method 400 comprises mixing a protein based binder and a cross linking agent to prepare a mixture. The protein based binder is prepared by a process comprising carboxylating a proteinaceous material by esterification of the proteinaceous material with a carboxylating agent to produce a carboxylated proteinaceous material, and denaturing the carboxylated proteinaceous material by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, a polyphenolic compound, and a natural resin such as shellac at a temperature range of 40 to 150 deg C. The method 400 further comprises applying the mixture to a wood material or an agricultural waste or a combination thereof to produce the wood based product.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[0013] Figure 1 illustrates a process 100 for preparing a protein based binder, in accordance with an embodiment of the present subject matter.
[0014] Figure 2 illustrates a process 200 for preparing a protein based binder, in accordance with an embodiment of the present subject matter.
[0015] Figure 3 illustrates a method 300 for making a wood based product, in accordance with an embodiment of the present subject matter.
[0016] Figure 4 illustrates a method 400 for making a wood based product, in accordance with an embodiment of the present subject matter.
[0017] Figure 5 illustrates a plot of Modulus of Rupture (MOR) of boards prepared with different pressing time intervals, in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION
[0018] Before the present process(s), composition(s) and product(s), enablement are described, it is to be understood that this disclosure in not limited to the particular processes, compositions, products and methodologies described, as there can be multiple possible embodiments of the present invention and which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present disclosure.
[0019] In one embodiment, a process for preparing a protein based binder is described. The process may comprise denaturing of a proteinaceous material by cooking the proteinaceous material. The proteinaceous material may be cooked in presence of water, an alkaline agent, a urea and a polyphenolic compound. The proteinaceous material may be cooked at a temperature range of 40 to 150 deg C to prepare the protein based binder.
[0020] In another embodiment, a process for preparing a protein based binder is described. The process may be comprising carboxylating a proteinaceous material by esterification of the proteinaceous material with a carboxylating agent to produce a carboxylated proteinaceous material. The process may further comprise denaturing of the carboxylated proteinaceous material by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, and a polyphenolic compound. The cooking of the carboxylated proteinaceous material may be carried out at a temperature range of 40 to 150 deg C to prepare the protein based binder.
[0021] In another embodiment, a composition of a protein based binder is described. The composition of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a range of 10 to 17 weight parts; c) an alkaline agent in a range of 1 to 4 weight parts; d) urea in a range of 8 to 12 weight parts, and e) a polyphenolic compound in a range of 2 to 8 weight parts.
[0022] In another embodiment, a composition of a protein based binder is described. The composition of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a rage of 14 to 50 weight parts; c) a carboxylating agent in a range of 2 to 4 weight parts; d) an alkaline agent in a range of 1 to 4 weight parts; and e) a polyphenolic compound in a range of 2 to 8 weight parts and f) a natural resin such as shellac in a range of 2 to 5 weight parts.
[0023] While aspects of described processes for preparing a protein based binder and compositions of a protein based binder may be applied in any number of different ways, the embodiments are described in the context of the following exemplary system.
[0024] Referring now to Figure 1, a process 100 for preparing a protein based binder is illustrated, in accordance with an embodiment of the present subject matter. In step 102, the process 100 may comprise adding water, an alkaline agent and urea to prepare a mixture. The mixture of water, the alkaline agent and the urea may be referred as “mixture A” hereafter for ease of understanding. In the step 102, 70% of the water may be added to the mixture A and 30% of the water may be kept for further use. The step 102 further may comprise stirring the mixture A till the alkaline agent and urea gets completely dissolved in the water. The urea may be added at a temperature range of 20 to 150 deg C. The alkaline agent may be selected from NaOH, KOH, sodium carbonate, sodium bicarbonate or ammonia solution. Preferred alkaline agent is NaOH. The alkaline agent may be added at a temperature ranging from 20 to 150 deg C. The alkaline agent is diluted prior to mixing in the water or the above said mixture A. The alkaline agent may be diluted to at most 50%.
[0025] In step 104 of the process 100 further comprises adding a polyphenolic compound and a proteinaceous material in succession to the mixture A. In step 104, remaining 30% of the water may be added to the mixture A. The proteinaceous material may be added slowly to the mixture A so that no lumps are formed. The proteinaceous material may be added in parts. The proteinaceous material may be added in 2 to 10 equal parts. By way of an example, the proteinaceous material may be a soy protein. The soy protein may be in form of soy flour, a soy concentrate, or a soy protein isolate. The soy flour or the soy concentrate or the soy protein isolate may be obtained from soy beans. The preferred soy protein is soy flour. The proteinaceous material may comprise at least 20% of carbohydrates by weight. The soy protein may comprise at least 20% of carbohydrates by weight.
[0026] According to another embodiment of the present disclosure, the proteinaceous material used in the present process may not be limited to soy protein and may comprise other protein sources known to a person skilled in the art. The protein source may be selected from soy protein, beans protein, corn protein, whey, wheat protein, keratin, albumin, gelatin, collagen, gluten, casein, a combination thereof and among other kind of proteins.
[0027] The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The preferred polyphenolic compound is tannin. The tannin may be selected from a source such as Quebracho (Schinopsis balansae or S. lorentzii, Anacardiaceae), Wattle (Acacia mearnsii), canaigre (Rumex hymenocephalus, Polygonaceae), European chestnut (Castanea sativa, Fagaceae) or Sumac.
[0028] In step 106 of the process 100 further comprises denaturing of the proteinaceous material by cooking the proteinaceous material in presence of water, the alkaline agent, urea and the polyphenolic compound to prepare the protein based binder. In the step 106, the denaturing of the proteinaceous material by cooking the proteinaceous material in presence of water, the alkaline agent, urea and the polyphenolic compound may be carried out at a temperature range of 40 to 150 deg C to prepare the protein based binder.
[0029] In one embodiment, in step 106, the polyphenolic compound may be added in a ratio of 0.31 with the soy protein. In another example, the polyphenolic compound such as tannin may be added in a ratio of 0.31 with the soy protein. In another embodiment, the ratio of addition of the soy protein with the polyphenolic compound such as tannin may be in a range of 1 to10. In one example, in step 104, urea may be added in a ratio of 1:1 with the soy protein by weight. The ratio of the urea with the soy protein may be in a range of 3:1 to 1:3.by weight. In one example, the alkaline agent may be added in 10 to 50 % of the soy protein by weight.
[0030] In step 106, a reactive diluent may be added to denature the proteinaceous material. The reactive diluent may be selected from a glycerol (glycerin), an ethylene glycol, a propylene glycol, or neopentyl glycol and polymeric version thereof. In the step 106, a boron compound may be added to mixture A to denature the proteinaceous material. The boron compound may be selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid. The ratio of reactive diluent to the soy protein may be 0.77. The ratio of boron compound to the soy protein may be 0.077.
[0031] In step 106, the proteinaceous material may be denatured (cooked) for a period of ranging from 15 to 500 minutes. In another embodiment, the proteinaceous material may be denatured (cooked) for a period of ranging from 15 to 300 minutes. In another embodiment, the proteinaceous material may be denatured (cooked) for a period of three hours, at a temperature ranging between 80 to 90 deg C. In step 106, the process 100 may comprise cooking the mixture of step 106 for about 3 hrs at 80 to 90 deg C. In the step 106, the soy flour/protein source may be denatured by heating to at least 40 to 150 deg C.
[0032] In step 108, the mixture of step 106 may be cooled up to 40 deg C to prepare the protein based binder. The protein based binder prepared in step 108 may be used for variety of applications.
[0033] In step 104, the process may further comprise adding defoamer and emulsifier to the remaining water i.e. 30% of the water, and the water with the defoamer and emulsifier may be added slowly to the above said mixture A.
[0034] Further, in step 108, the cooked mixture of step 106 may be cooled up to around 40 deg C. The process in step 108 further may comprise adding preservative and biocide to the cooled mixture at 40 deg C and in step 108, the cooled mixture may be stirred for around 30 minutes to prepare the protein based binder. Thus the process results into the formation of the protein based binder for application. The defoamer and emulsifier may be used in above mixture can be any defoamer or emulsifier known to a person skilled in the art. The defoamer may be selected from an oil based defoamer, a water based defoamer, a glycol based defoamer or a silicon based defoamer. The emulsifier may be selected from a nonionic emulsifier, an anionic emulsifier, or a cationic emulsifier. Preferably the nonionic emulsifier is selected.
[0035] According to the exemplary embodiment of the present disclosure, the proteinaceous material used is the soy protein. The proportion of alkaline agent such as NaOH and urea in the above said mixture A may be adjusted in order to achieve optimum denaturing of the soy protein and to achieve lower viscosity of the protein based binder that is soy based binder. Further, addition of glycerin, tannin, casein and borax into the mixture results into reduction of viscosity of the soy based binder and high solid content of the soy based binder. The optimum use of NaOH and urea for denaturing of the soy protein and cooking of the soy protein in presence of glycerin, tannin, casein and borax results into preserving the required tertiary and quaternary structures of the soy protein. The addition of tannin, glycerin, casein and borax into the mixture of soy protein of step 106 also results into better water resistance property and improved stability of the soy based binder. Glycerin acts as a plasticizer in the present process 100 and provides additional cross linking sites in the soy based binder. Further reduction of viscosity or increase in the solid content with similar viscosity in the soy based binder is possible by addition of tannin. Due to the presence of multiple hydroxyl groups in a tannin molecule, there is complex formation in the mixture which reduces viscosity of the soy based binder. After application of the soy based binder, in the wood based product, cross linking of lignocellulosic materials of the wood based product through hydroxyl groups of the tannin results into stronger bonding and better water resistance of the wood based product.
[0036] Referring now to Figure 2, a process 200 for preparing a protein based binder is illustrated, in accordance with an embodiment of the present subject matter. In step 202, water and a carboxylating agent may be added to prepare diluted carboxylic acid. The carboxylating agent may be added 2 to 4 weight parts of the total weight of the protein based binder. In the step 202, 70% of the water may be added to the carboxylating agent and 30% of the water may be kept for further use. In another embodiment, a dilute acid/ a protonating agent may be added to the water before adding the carboxylating agent to reduce pH of water to a range of 4 to 5. The protonating agent may be a diluted strong acid or a weak acid. By way of an example, the protonating agent may be diluted H2SO4 or diluted HCl or weak acids such as boric acid. The ratio of carboxylating agent to the soy protein may be 0.045.The ratio of protonating agent to the soy protein may be 0.011.
[0037] Further, the mixture of water and dilute acid may be stirred for 15 minutes. Further, in step 202, the proteinaceous material may be added slowly to the mixture of the diluted carboxylating agent and the dilute acid/protonating agent so that no lumps are formed. The proteinaceous material may be added in parts. The proteinaceous material may be added in 2 to 10 equal parts. By way of an example, the proteinaceous material may be a soy protein. The soy protein may be in form of soy flour, a soy concentrate, or a soy protein isolate. The soy flour or the soy concentrate or the soy protein isolate may be obtained from soy beans. The preferred soy protein is soy flour. The proteinaceous material may comprise at least 20% of carbohydrates by weight. The soy protein may comprise at least 20% of carbohydrates by weight.
[0038] In step 204, the proteinaceous material may be carboxylated by esterification of the proteinaceous material with the carboxylating agent to produce a carboxylated proteinaceous material. The proteinaceous material may be carboxylated in acidic medium. The carboxylating agent may be a dicarboxylic acid. The dicarboxylic acid may be selected from a group consisting of a succinic acid, an oxalic acid, a malonic acid, an adipic acid, and an azealic acid. The step 204 further comprises heating while stirring the mixture of the proteinaceous material and the carboxylating agent for 1 hr at 80 – 85 degree C to produce a carboxylated proteinaceous material.
[0039] In step 206, an alkaline agent may be added to the carboxylated proteinaceous material to prepare a mixture. The mixture of the alkaline agent and the carboxylated proteinaceous material may be referred as “mixture B” hereafter for ease of understanding. The alkaline agent may be selected from NaOH, KOH, sodium carbonate, sodium bicarbonate or ammonia solution. Preferred alkaline agent is NaOH. The alkaline agent may be added at a temperature ranging from 20 to 150 deg C. The alkaline agent may be added in 10 to 50 % of the soy protein by weight. The step 206 further may comprise stirring the mixture B.
[0040] In step 206, the process 200, may further comprise adding defoamer and emulsifier to the remaining water i.e. 30% of the water, and the water with the defoamer and the emulsifier may be added slowly to the mixture B. The defoamer and the emulsifier may be any defoamer or emulsifier known to a person skilled in the art. The defoamer may be selected from an oil based defoamer, a water based defoamer, a glycol based defoamer or a silicon based defoamer. The emulsifier may be selected from a nonionic emulsifier, an anionic emulsifier, or a cationic emulsifier. Preferably the nonionic emulsifier is selected.
[0041] In the step 206, a boron compound may be added to mixture B to denature the carboxylated proteinaceous material. The boron compound may be selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid. The ratio of boron compound to the soy protein may be 0.057.
In step 208, a polyphenolic compound and a natural resin such as shellac may be added to the mixture B to denature the carboxylated proteinaceous material. The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The preferred polyphenolic compound is tannin. The tannin may be selected from a source such as Quebracho (Schinopsis balansae or S. lorentzii, Anacardiaceae), Wattle (Acacia mearnsii), canaigre (Rumex hymenocephalus, Polygonaceae), European chestnut (Castanea sativa, Fagaceae) or Sumac. The natural resin may be selected from a group consisting shellac, rosin, frankinscense, or rosin derivatives.
[0042] In one embodiment, in step 208, the polyphenolic compound may be added in a ratio of 4.375 with the soy protein. In another embodiment, a ratio of the soy protein to tannin may be of 4.375 by weight. In another embodiment, a ratio of addition of the soy protein with the polyphenolic compound such as tannin may be in a range of 1 to10.
[0043] The step 208 may also comprise adding a reactive diluent to the mixture B to denature the carboxylated proteinaceous material. The reactive diluent may be selected from a glycerol (glycerin), an ethylene glycol, a propylene glycol, or neopentyl glycol and polymeric version thereof. The ratio of reactive diluent to the soy protein may be 0.44.
[0044] In step 210, the carboxylated proteinaceous material may be denatured by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, and a polyphenolic compound, and shellac at a temperature range of 40 to 150 deg C to prepare the protein based binder.
[0045] In another embodiment, in step 210, the carboxylated proteinaceous material may be denatured by cooking the carboxylated proteinaceous material in presence of water, the alkaline agent, the polyphenolic compound, the shellac, the reactive diluent, and the boron compound at a temperature range of 40 to 150 deg C.
[0046] In step 210, the carboxylated proteinaceous material may be denatured (cooked) for a period of ranging from 15 to 500 minutes. In another embodiment, the carboxylated proteinaceous material may be denatured (cooked) for a period of ranging from 15 to 300 minutes. In another embodiment, the carboxylated proteinaceous material may be denatured (cooked) for a period of three hours, at a temperature ranging between 80 to 90 deg C. In step 210, the process 200 may comprise cooking the mixture of step 208 for about 3 hrs at 80 to 90 deg C. In the step 210, the soy flour/ carboxylated proteinaceous material may be denatured by heating to at least 40 to 150 deg C.
[0047] Further, in step 212, the cooked mixture of step 210 may be cooled up to around 40 deg C. The process in step 212 further may comprise adding preservative and biocide to the cooled mixture at 40 deg C and in step 212, the cooled mixture may be stirred for around 30 minutes to prepare the protein based binder. Thus the process 200 may result into the formation of the protein based binder. The pot life of the protein based binder of the present process may be 5 minute to 100 hour.
[0048] The carboxylation step (esterification step) is described in detail. Carboxylation is an esterification reaction which is carried out in acidic medium. The medium is made acidic by using diluted strong acids (diluted H2SO4, HCl) or weak acids like boric acid to pH of 4-5. Then carboxylation is done with dicarboxylic acids such as succinic acid, oxalic acid, malonic acid, adipic acid, azealic acid etc. Reaction is carried out at 70 to 80 degree C for 1 hour. After one hour, the medium is made basic by adding NaOH or KOH to pH about 9. Carboxylation reaction is monitored by estimating acid value at different time interval.
[0049] According to the exemplary embodiment of the present disclosure, the proteinaceous material used is the soy protein. The proportion of carboxylation of the soy protein may be adjusted in order to achieve optimum denaturing of the soy protein and to achieve lower viscosity of the protein based binder that is soy based binder. Further, addition of glycerin, tannin, shellac and borax into the mixture results into reduction of viscosity of the soy based binder and high solid content of the soy based binder. The optimum use of carboxylating agent and NaOH for denaturing of the soy protein and cooking of the soy protein in presence of glycerin, tannin, shellac and borax results into preserving the required tertiary and quaternary structures of the soy protein. The addition of tannin, glycerin, shellac and borax into the mixture of soy protein also results into better water resistance property and improved stability of the soy based binder. Glycerin acts as a plasticizer in the present process 200 and provides additional cross linking sites in the soy based binder. Further reduction of viscosity or increase in the solid content with similar viscosity in the soy based binder is possible by addition of tannin. Due to the presence of multiple hydroxyl groups in a tannin molecule, there is complex formation in the mixture which reduces viscosity of the soy based binder. After application of the soy based binder, in wood based product, cross linking of lignocellulosic materials of the wood based product through hydroxyl groups of tannin results into stronger bonding and better water resistance of the wood based product. Further, as there is no addition of urea in the process 200 to prepare the protein based binder, there is no emission of ammonia from the protein bases binder. Hence the protein based binder is not harmful to human beings and eco-friendly. As there is no ammonia smell coming from the protein based binder, the protein based binder is suitable for indoor as well as outdoor applications.
[0050] The protein based binder prepared in above described process 100 and process 200 may be used to manufacture a wood based product. The protein based binder prepared in above described process 100 and process 200 may be used by mixing with a cross linking agent/hardener to manufacture the wood based product. The wood based products may include fiber board, particle board, wafer board, oriented strand board, lumber, plywood, hard board and similar other products. The raw material or the lignocellulosic material used to prepare the wood based product may include wood dust, agricultural dust, agricultural husk, baggase, wood chips, veneer, wheat stalks, rice husk, rice stalks, coir, pith, hemp, wood pulp. The raw material or the lignocellulosic material used to prepare the wood based product may be in the form of dust, husk, chips, straws, ply, powders, flakes, particles, peels, crumbles and so on. According to another embodiment, inorganic materials may be used to prepare the wood based product. The inorganic materials may be used in combination with the lignocelluloses to prepare the wood based product. The inorganic materials used may be pretreated inorganic materials.
[0051] According to another embodiment of the present disclosure, referring now to Figure 3, a method 300 for making a wood based product is described. According to an embodiment of the present disclosure, the protein based binder prepared by process 100 may be used in method 300 to make the wood based product. The method 300 comprises steps 302 to 308 to prepare the protein based binder. The protein based binder may be prepared by a process comprising denaturing of a proteinaceous material by cooking the proteinaceous material in presence of water, an alkaline agent, a urea and a polyphenolic compound, at a temperature range of 40 to 150 deg C.
[0052] In step 302, the method 300 may comprise adding water, an alkaline agent and urea to prepare a mixture. The mixture of water, the alkaline agent and the urea may be referred as “mixture A” hereafter for ease of understanding. The step 302 further may comprise stirring the mixture A till the alkaline agent and urea gets completely dissolved in the water. The urea may be added at a temperature range of 20 to 150 deg C. The alkaline agent may be selected from NaOH, KOH, sodium carbonate, sodium bicarbonate or ammonia solution. Preferred alkaline agent is NaOH. The alkaline agent may be added at a temperature ranging from 20 to 150 deg C. The alkaline agent is diluted prior to mixing in the water or the above said mixture A. The alkaline agent may be diluted to at most 10%.
[0053] In step 304 of the method 300 further comprises adding a polyphenolic compound and a proteinaceous material in succession to the mixture A. In step 304, remaining 30% of the water may be added to the mixture A. By way of an example, the proteinaceous material may be a soy protein. The soy protein may be in form of soy flour, a soy concentrate, or a soy protein isolate. The soy flour or the soy concentrate or the soy protein isolate may be obtained from soy beans. The preferred soy protein is soy flour.
[0054] According to another embodiment of the present disclosure, the proteinaceous material used in the present process may not be limited to soy protein and may comprise other protein sources known to a person skilled in the art. The protein source may be selected from soy protein, beans protein, corn protein, whey, wheat protein, keratin, albumin, gelatin, collagen, gluten, casein, a combination thereof and among other kind of proteins.
[0055] The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The preferred polyphenolic compound is tannin. The tannin may be selected from a source such as Quebracho (Schinopsis balansae or S. lorentzii, Anacardiaceae), Wattle (Acacia mearnsii), canaigre (Rumex hymenocephalus, Polygonaceae), European chestnut (Castanea sativa, Fagaceae) or Sumac.
[0056] In step 306 of the method 300 further comprises denaturing of the proteinaceous material by cooking the proteinaceous material in presence of water, the alkaline agent, urea and the polyphenolic compound at a temperature range of 40 to 150 deg C to prepare the protein based binder. In step 306, a reactive diluent may be added to denature the proteinaceous material. The reactive diluent may be selected from a glycerol (glycerin), an ethylene glycol, a propylene glycol, or neopentyl glycol and polymeric version thereof. In the step 306, a boron compound may be added to the mixture A to denature the proteinaceous material. The boron compound may be selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid.
[0057] In step 306, the proteinaceous material may be denatured (cooked) for a period of ranging from 15 to 500 minutes. In another embodiment, the proteinaceous material may be denatured (cooked) for a period of three hours, at a temperature ranging between 80 to 90 deg C. In step 306, the method 300 may comprise cooking the mixture (of step 306) for about 3 hrs at 80 to 90 deg C. In step 308, the mixture of step 306 may be cooled up to 40 deg C to prepare the protein based binder. The protein based binder may be used for variety of applications.
[0058] The method 300, in step 310 comprises preparing a mixture of the protein based binder and a cross linking agent. The step 310 may comprise mixing the protein based binder and the cross linking agent in a predetermined ratio. The mixing ratio of the protein based binder and the cross linking agent may be in a range from 1:1 to 1:0.001. The ratio of protein based binder to the cross linking agent/hardener may be in a range from 999:0.1 to 75:25 on dry basis. By way of an example, the protein based binder and the cross linking agent may be mixed in a ratio of 95:5% w/w. The mixture may be stirred well in order to properly mix the protein based binder and the cross linking agent.
[0059] The method 300 in step 312 may comprise applying the mixture to wood material or agricultural waste or a combination thereof to make the wood based product. Further, the step 310 may comprise adding water to the mixture in order to achieve required viscosity for application to the wood material and/or the agricultural waste. By way of an example, the required viscosity may be less than or equal to 20 sec by Ford Cup 4. The preferred viscosity of the protein based binder after dilution is 1 to 1000 seconds on Ford Cup 4. The so prepared mixture of the protein based binder and the cross linking agent/hardener may be applied to wood based or agricultural waste material to make wood based products such as wood composites, particle board, plywood and so on.
[0060] According to another embodiment of the present disclosure, referring now to figure 4 a method 400 for making a wood based product is described. According to an embodiment of the present disclosure, a protein based binder prepared by the process 200 may be used in the method 400 to make the wood based product. The method 400 comprises steps 402 to 412 to prepare the protein based binder. In step 402, water and a carboxylating agent may be added to prepare diluted carboxylic acid. In another embodiment, a dilute acid/ a protonating agent may be added to the water before adding the carboxylating agent to reduce pH of water to a range of 4 to 5. Further, in step 402, the proteinaceous material may be added slowly to the mixture of the diluted carboxylating agent and the dilute acid/protonating agent so that no lumps are formed. By way of an example, the proteinaceous material may be a soy protein. The soy protein may be in form of soy flour, a soy concentrate, or a soy protein isolate.
[0061] In step 404, the proteinaceous material may be carboxylated by esterification of the proteinaceous material with the carboxylating agent to produce a carboxylated proteinaceous material. The proteinaceous material may be carboxylated in acidic medium. The carboxylating agent may be a dicarboxylic acid. The dicarboxylic acid may be selected from a group consisting of a succinic acid, an oxalic acid, a malonic acid, an adipic acid, and an azealic acid.
[0062] In step 406, an alkaline agent may be added to the carboxylated proteinaceous material to prepare a mixture. The mixture of the alkaline agent and the carboxylated proteinaceous material may be referred as “mixture B” hereafter for ease of understanding. The alkaline agent may be selected from NaOH, KOH, sodium carbonate, sodium bicarbonate or ammonia solution.
[0063] The step 406 may further comprise adding defoamer and emulsifier to the mixture B. In the step 406, a boron compound may be added to the mixture B to denature the carboxylated proteinaceous material. The boron compound may be selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid.
[0064] In step 408, a polyphenolic compound and a natural resin such as shellac may be added to the mixture B to denature the carboxylated proteinaceous material. The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The preferred polyphenolic compound is tannin. The tannin may be selected from a source such as Quebracho (Schinopsis balansae or S. lorentzii, Anacardiaceae), Wattle (Acacia mearnsii), canaigre (Rumex hymenocephalus, Polygonaceae), European chestnut (Castanea sativa, Fagaceae) or Sumac. The natural resin may also be selected from a group consisting of shellac, rosin, frankinscense, or rosin derivatives.
[0065] The step 408 may also comprise adding a reactive diluent to the mixture B to denature the carboxylated proteinaceous material. The reactive diluent may be selected from a glycerol (glycerin), an ethylene glycol, a propylene glycol, or neopentyl glycol and polymeric version thereof. In step 410, the carboxylated proteinaceous material may be denatured by cooking the carboxylated proteinaceous material in presence of water, the alkaline agent, the polyphenolic compound, the shellac, the reactive diluent, and the boron compound at a temperature range of 40 to 150 deg C. Further, in step 412, the cooked mixture of step 210 may be cooled up to around 40 deg C. The method in step 412 further may comprise adding preservative and biocide to the cooled mixture at 40 deg C to prepare the protein based binder.
[0066] The method 400 in step 414 comprises preparing a mixture of the protein based binder and a cross linking agent. The step 414 may comprise mixing the protein based binder and the cross linking agent in a predetermined ratio. The mixing ratio of the protein based binder and the cross linking agent may be in a range from 1:1 to 1:0.001. The ratio of protein based binder to the cross linking agent/hardener may be in a range from 999:0.1 to 75:25 on dry basis. By way of an example, the protein based binder and the cross linking agent may be mixed in a ratio of 95:5% w/w. The mixture may be stirred well in order to properly mix the protein based binder and the cross linking agent.
[0067] The method 400 in step 416 may comprise applying the mixture to wood material or agricultural waste or a combination thereof to make the wood based product. Further, the step 416 may comprise adding water to the mixture in order to achieve required viscosity for application to the wood material and/or the agricultural waste. By way of an example, the required viscosity may be less than or equal to 20 sec by Ford Cup 4. The preferred viscosity of the protein based binder after dilution is 1 to 1000 seconds on Ford Cup 4. The so prepared mixture of the protein based binder and the cross linking agent/hardener may be applied to wood based or agricultural waste material to manufacture wood based products such as wood composites, particle board, plywood and so on.
[0068] The cross linking agent used in method 300 and method 400 may be a formaldehyde free cross linking agent. The cross linking agent or the hardener may be selected from a group comprising Polyamino epichlorohydrine (PAE), isocyanates, inorganic salts, aldehyde, aldehyde starch, epoxy, polyamine, epichlorohydrine resin, urea aldehyde resin, or glyoxal, urea glyoxal or a combination thereof. Preferably, the cross linking agent is polymeric methyl diphenyl diisocynate. Preferably, the cross linking agent can be selected from polyamidoamine epichlorohydrine resin, polyalkylene polyamine-epichlorohydrine or amine polymer- epichlorohydrine resin. The cross linking agent may be added in an amount between 0.1 to 80 % of concentration. According to another embodiment of the present disclosure, the cross linking agent may be formaldehyde containing cross linking agent. The cross linking agent may be selected from formaldehyde, phenol formaldehyde, urea formaldehyde, melamine urea formaldehyde, phenol resorcinol and any combination thereof.
[0069] The wood based products produced/made in the method 300 and the method 400 may include fiber board, particle board, wafer board, oriented strand board, lumber, plywood, hard board and similar other products. The raw material or the lignocellulosic material used to prepare the wood based product may include wood dust, agricultural dust, agricultural husk, baggase, wood chips, veneer, wheat stalks, rice husk, rice stalks, coir, pith, hemp, wood pulp, saw dust. The raw material or the lignocellulosic material used to prepare the wood based product may be in the form of dust, husk, chips, straws, ply, powders, flakes, particles, peels, crumbles and so on.
[0070] According to another embodiment of the present disclosure, inorganic materials may be used to prepare the wood based product. The inorganic materials may be used in combination with the lignocelluloses to prepare the wood based product. The inorganic materials used may be pretreated inorganic materials.
[0071] A method for making the wood based product, referring to method 300 and method 400 is described. The method comprises transferring a mixture of wood material and/ or agricultural waste (dust or husk) and the protein based binder and the cross linking agent to a mould and pressing at a temperature ranging from 100-250 degree C to get the wood based product. The temperature range may change based on a nature of the wood based product. The mixture may be pressed in order to get required density of the wood based product. The mixture of the wood material, agricultural waste, the protein based binder and cross linking agent may be pressed in presence of heat and/or pressure. The required pressure to press the mixture may be in a range from 1kg/cm2 to 100kg/cm2. The required temperature in the mould and pressing of mixture may be in a range from 50 to 250 Deg C. The preferred time for pressing the mixture may range from 2 to 1800 seconds.
[0072] In one embodiment, a composition 500 of a protein based binder is described. The composition 500 of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a range of 10 to 17 weight parts; c) an alkaline agent in a range of 1 to 4 weight parts; d) urea in a range of 8 to 12 weight parts, and e) a polyphenolic compound in a range of 2 to 8 weight parts. The composition 500 may further comprise a reactive diluent. The composition 500 may comprise the reactive diluent of 10 weight parts of the composition 500. The reactive diluent may be selected from a group consisting of a glycerol (glycerin), an ethylene glycol, a propylene glycol, and a neopentyl glycol. The composition 500 may further comprise a boron compound. . The composition 500 may comprise the boron compound of 1 weight part of the composition 500. The boron compound may be selected from a group consisting of sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, and a salt of boric acid. The proteinaceous material may be a soy protein. The soy protein may be in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans. The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The alkaline agent may be selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, or ammonia solution. The composition 500 may further comprise at least one of a defoamer, an emulsifier, and a biocide, in a range from 0.1 to 10 % w/w of the protein based binder.
[0073] In one embodiment, a composition 600 of a protein based binder is described. The composition 600 of the protein based binder comprises a reaction product of: a) water in a range of 50 to 60 weight parts; b) a proteinaceous material in a rage of 14 to 50 weight parts; c) a carboxylating agent in a range of 2 to 4 weight parts; d) an alkaline agent in a range of 1 to 4 weight parts; and e) a polyphenolic compound in a range of 2 to 8 weight parts and f) a natural resin such as shellac in a range of 2 to 5 weight parts.
[0074] The composition 600 may further comprise a reactive diluent. The composition 600 may comprise the reactive diluent as 7.6 weight parts of the composition 600. The reactive diluent may be selected from a group consisting of a glycerol (glycerin), an ethylene glycol, a propylene glycol, and a neopentyl glycol. The composition 600 may further comprise the proteinaceous material carboxylated with the carboxylating agent. The composition 600 may further comprise a boron compound selected from a group consisting of sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, and a salt of boric acid. The composition 600 may comprise the boron compound as 1 weight part of the composition 600. The proteinaceous material may be a soy protein and the soy protein is in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans.
[0075] The polyphenolic compound may be selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL). The natural resin may also be selected from a group consisting of shellac, rosin, frankincense, or rosin derivatives. The alkaline agent may be selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, or ammonia solution. The carboxylating agent may be a dicarboxylic acid. The dicarboxylic acid may be selected from a group consisting of a succinic acid, an oxalic acid, a malonic acid, an adipic acid, and an azealic acid. The composition 600 may further comprise a protonating agent. The protonating agent may be a diluted strong acid or a weak acid. The protonating agent may be added to the water before adding the carboxylating agent to reduce pH of water to a range of 4 to 5. By way of an example, the protonating agent may be diluted H2SO4 or diluted HCl or weak acids such as boric acid.
[0076] The composition 600 may further comprise a defoamer, an emulsifier, and a biocide in a range from 0.1 to 10 weight parts of the protein based binder.
[0077] The Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0078] Some embodiments enable process(s) and composition(s) to prepare a protein based binder with improved water resistance and the protein based binder is stable.
[0079] Some embodiments enable process(s) and composition(s) to prepare a stable protein based binder with improved viscosity with high solid content.
[0080] Some embodiments enable process(s) and composition(s) to prepare a wood based product using the protein based binder with improved strength, improved water resistance and reduced swelling.
[0081] Some embodiments enable process(s) and composition(s) to prepare a protein based with no addition of urea, hence no emission of ammonia from the protein bases binder.
[0082] Some embodiments enable process(s) and composition(s) to prepare a protein based binder which is eco-friendly, not harmful to human beings and is suitable for indoor as well as outdoor applications.
EXAMPLE 1
[0083] An example of a process for preparation of 1000 gram of Protein based binder ‘P’ is described. 1) Take 500 gm (total water to be added 560gm) of water in kettle fixed with stirrer. 2) Add denaturing agents such as urea [100gm] and caustic (40% NaOH) [37gm] in the kettle. 3) Start stirring the mixture of step 2, speed of the stirrer is about 300 rpm. Continue stirring till urea is completely dissolved. 4) Then add other ingredients like borax [10gm], sodium sulphite, calcium carbonate to the mixture of step 3. Stir the mixture for 5 min and add defoamer and emulsifier to the mixture under stirring condition. 5) Take 130gm of soy flour and add slowly to the mixture of step 4 (add in 3 parts of soy flour keeping 10 minutes gap in between). After 10 min of final addition of soy flour, add 40 gm wattle extract powder (tannin powder) slowly. 6) Let the mixture of step 5 stir for 15 minutes and then add reactive diluent (glycerine [100gm]) to the mixture. Add remaining water to the mixture. 7) Start heating the mixture of step 6, once temperature reaches above 90 degree and maintain the temperature between 90 and 95 degree C for 3 hrs. 8) Cool the mixture of step 7 below 40 degree C and then add biocides to the mixture. After cooling the mixture and after adding the biocide, stir the cooled mixture for 15 min.
[0084] The tannin used in the present examples is Wattle. The wattle is also called mimosa tannin. Shellac is a resin secreted by female Lac bug also called as Laccifer lacc mainly found in India and Thailand. Tannin used in the present disclosure is procured from Tanmix™ company and Poplon chemie™. Shellac used in the present example is procured from Paras™ internationals, Mumbai.
Table 1: Physical parameters of the Protein based binder P
Viscosity 4.2 poise Viscosity is measured with Brookfield viscometer (model RVT). Spindle no 2 at 20 RPM.
% solid 38% Solids were calculated at 1050C for 90 minutes.
pH 10.61 pH was measured with a pH meter of make BIO LAB model no BL 501.
Appearance brown liquid (no lumps were found)
[0085] Wood based product such as a board is prepared using the Protein based binder P. Board preparation is described below. Two hardeners are used to evaluate strength of the Protein based binder P such as a) Hardener A80 and b) Hardener A40. Two types of Hardeners -Isocyanate and modified amine adducts- PAE are used in present examples.
[0086] Take protein based binder P and hardener A80 in ratio 80:20 and mix well to prepare a mixture and check Ford cup viscosity (B4) and go on adding water till viscosity of the mixture is in a range 15 to 20 sec. 120 gram protein based binder P for which 30 gm of hardener A80 and 8 gram of water is added to get 17 seconds Ford cup B4 viscosity of the mixture. Bagasse is mixed with the mixture of protein based binder P and Hardener A80 in ratio of 80: 20 by calculating the amount of final mixture required for getting 700 kg/m^3 density. A board1 is prepared in LAB press with standard 3 mm mould. Condition for pressing the board1 is as follows in Table 2.
Table 2: Condition for pressing the board1, board2, board3
Pressure 30 kg/cm2
Time 10 min
Temperature 135 Deg C (both the plates)
[0087] Take the protein based binder P and a Hardener A40 in ratio 90:10 and mix to prepare a mixture, check the Ford cup viscosity (B4) of the mixture and go on adding water till viscosity of the mixture is in a range 15 to 20 sec. 155 gram protein based binder P for which 17 gm of hardener A40 and 42 gram of water is added to get 17 seconds Ford cup B4 viscosity. Bagasse is mixed with the mixture of protein based binder P and Hardener A40, in ratio of 80: 20 by calculating the amount of final mixture required for getting 700 k/m^3 density. A board2 is prepared in LAB press with standard 3 mm mould using the mixture of the protein based binder P and the Hardener A40. Condition for pressing of composite is as given in Table 2. The board1 and board2 prepared as described above are cut in required dimensions and properties like modulus of rupture (MOR), Modulus of elasticity (MOE), water absorption, thickness swelling were measured for both the boards1 and board2 are provided in Table 3. For comparison purpose with urea formaldehyde resin, Powder UF resin is taken and made ready to use by mixing with water. 70 gm of Powder UF resin is mixed with 80 gram of water to get 17 sec viscosity in B4 Ford cup. Board3 is prepared in similar way using the above mixture of water and the Powder UF resin as stated above in Table 2. Properties of the board3 are also provided in column3 of Table3 for comparison.
Table 3: Properties of Board1, Board2, and Board3
properties With hardener A80
(Board1) With hardener A40
(Board2) Urea Formaldehyde
(Board3)
Flexural strength (kg/cm2) 111.17
75.23 136.94
Modulus of rupture MOR(kg/cm2) 113.02 75.25 120.02
Modulus of elasticity, MOE (kg/cm2) 12691.93 - 10060.13
Thickness swelling in water, 24 hours (%) 50.06 56.92 55.20
Water absorption in 24 hours (%) 109.82 136.93 129.47
[0088] It is observed from Table 3 results that protein based binder P with Hardener A80 gives comparable result to the UF resin while the Hardener A40 seems to be inferior. With Hardener A80 the protein based binder P passes the MOR value of minimum 110 kg/cm2. Using hardener A80 boards were prepared for different press time intervals that is for 7.5 min, 10 min and 12.5 min at 30 kg/cm2 pressure and 135 Deg C temperature and results of the same are provided in Table 4 below.
Table 4: Properties of the boards prepared using Hardener A80 for different press time intervals and Properties of the board prepared with Urea formaldehyde resin
Properties Press for 7.5 min Press for 10 min Press for 12.5 min Urea Formaldehyde
Flexural strength (kg/cm2) 70.91
111.17
77.05 136.94
Modulus of rupture , MOR(kg/cm2) 70.78 113.02 77.05 120.02
Modulus of elasticity, MOE (kg/cm2) 8221.1 12691.93 9305.52 10060.13
Thickness swelling in 24 hours. (%) 39.95 50.06 40.08 55.20
Water absorption in 24 hours (%) 106.31 109.82 130.39 129.47
[0089] Figure 5, described a plot of Modulus of Rupture (MOR) of boards prepared for different pressing time intervals. Figure 5 shows that press time of 10 minutes gives optimum curing, and high MOR, after that degradation of bond starts for the board. Further, water absorption and thickness swelling of the board decreases as press time decreases.
EXAMPLE 2
[0090] An Example2 of a process for preparing 1000 gram of protein based binder ‘B’ (high soy content) is described below. 1) Take 450 gm (total water to be added 500gm) of water in kettle fixed with stirrer. Add dilute acids to the water to reduce pH of the water between 4 to 5. Stir a mixture of the water and the dilute acid for 15 min. 2) Add carboxylic acid to the mixture step 1. Here a carboxylic acid such as a succinic acid (8 grams) is added to the mixture. 3) Take 175 gram soy flour and add slowly to the mixture of step 2 (add the soy flour in 3 parts keeping 10 minutes gap in between.) 4) Start heating the mixture of step 3, stir the mixture for 1 hr at 80 – 85 degree C. 5) Add denaturing agent viz. 60 gm of caustic (40% NaOH) to the mixture of step 4. Then add other ingredients like borax (10 gm), sodium sulphite, calcium carbonate to the mixture. 6) Stir the mixture of step 5 for 5 min and then add defoamer and emulsifier to the mixture and stir for 5 more minutes. 7) Add 40 gm of tannin to the mixture of step 6 slowly under stirring. 8) Add 36 gm of shellac to the mixture of step 7 slowly under stirring. 9) Cook the mixture of step 8 for 15 minutes and then add reactive diluent (76 gm glycerin) to the mixture. 10) Increase the temperature of the mixture of step 9, once temperature reaches above 90 degree, maintain the temperature between 90 and 95 degree C for 3 hrs. Cool the mixture below 40 degree C and then add biocides to the mixture and stir the mixture for 15 min.
Table 5: Physical parameters of the Protein based binder B
Viscosity 13 poise Viscosity is measured with Brookfield viscometer (model RVT). Spindle no 2 at 20 RPM.
% solid 39.87 % Solids were calculated at 1050C for 90 minutes.
pH 10.25 pH was measured with a pH meter of make BIO LAB model no BL 501.
Appearance brown liquid (no lumps were found)
[0091] Two hardeners are used to evaluate properties of the protein based binder B using a) Hardener A80 and b) Hardener A40. The protein based binder B, the Hardener A40, and Hardener A80 are mixed in a ratio 80:20 (wherein the protein based binder 80% and hardener 20%) to prepare a mixture and the Ford cup viscosity (B4) of the mixture is checked continuously while adding water till viscosity achieved is in a range of 15 to 20 sec. 120 gram of the protein based binder B is taken for which 30 gm of hardener A80 and 40 gram of water is mixed to get 16.5 seconds Ford cup B4 viscosity. Bagasse is mixed with mixture of the protein based binder B and Hardener A80, in ratio of 80: 20 by calculating the amount of final mixture required for getting 700 k/m^3 density. A board1 is prepared in LAB press with standard 3 mm mould. Condition for pressing of composite are as mentioned in Table 2.
[0092] Further, while using the hardener A40, the protein based binder B and hardener A40 are mixed in a ratio 90:10 to prepare a mixture, the Ford cup viscosity (B4) of the mixture is checked continuously while adding water till viscosity of the mixture is in a range of 15 to 20 sec. 270 gram protein based binder B for which 30 gm of hardener A40 and 160 gram of water is added to get 18 seconds Ford cup B4 viscosity of the mixture. Bagasse is mixed with mixture of the protein based binder B and hardener A40 in ratio of 80: 20 by calculating the amount of final mixture required for getting 700 k/m^3 density. A board2 is prepared in LAB press with standard 3 mm mould. Conditions for pressing the board2 are as mentioned in Table 2. For comparison with urea formaldehyde resin, Powder UF resin is used to make a board 3. The Powder UF resin is mixed with water while making the board 3. 70 gm of UF powder is mixed with 80 gram of water to get 17 sec viscosity in B4 Ford cup. Board3 is prepared following similar steps as stated above. The board1, board2 and board3 are cut in required dimensions and properties like modulus of rupture (MOR) Modulus of elasticity (MOE), water absorption, thickness swelling are measured and provided in Table 6 below.
Table 6: Properties of Board1, Board2, and Board3
properties With hardener A80
(Board1) With hardener A40
(Board2) Urea Formaldehyde
(Board3)
Flexural strength (kg/cm2) 108.37
66.77 136.94
Modulus of rupture , MOR(kg/cm2) 114.30 68.91 120.02
Modulus of elasticity, MOE (kg/cm2) 13785.99 7787.29 10060.13
Thickness swelling in 24 hours. (%) 45.39 52.27 55.20
Water absorption in 24 hours (%) 96.30 118.33 129.47
[0093] It is observed from Table 6 results that carboxylation of the proteinaceous material while preparing the protein based binder gives better result as observed between Example 1 and Example 2. Hardener A80 with the protein based binder B gives best result when compared with Powder Urea formaldehyde (UF) resin. Elastic modulus is more for the protein based binder B with A80 hardener. Thickness swelling and water absorption is less for the boards prepared with the protein based binder B than that of the board prepared with UF resin. This proves that carboxylation and addition of tannin improves the properties of final wood based products-boards.
[0094] Pot life study for 3 protein based binders formulations with Hardener A40 is provided in Table 7. It is observed that there is increase in viscosity with time. Pot life of the protein based binders formulations when mixed with Hardener A40 is not more than 6 hours for this application.
[0095] However, the protein based binders formulations show much longer pot life (8 – 10 hrs) when mixed with Hardener A80.
Table 7: Pot life study for 3 protein based binder formulations with Hardener A40
Binder Name B A1B2 A3B1
Binder Quantity gm 169 270 180
HARDENER (A40) gm 18 30 20
WATER gm 78 0 70
% Solids Of Mix 32.22 46.16 34.26
Viscosity by Ford cup 4 (sec) after
0 min 15.3 18 15.66
30 min 16.3 18 16.07
60 min 17.8 18.3 17
180 min 19 19 17
330 min 21 19.5 19
1440 min 22 21 20
[0096] Further, results of different formulations of the protein based binders with hardener A80 (non isocyanate) in ratio 80:20 (protein based binder:hardener) are provided in Table 8.
Table 8: Results of different formulations of protein based binders with hardener A80 (non isocyanate) in ratio 80:20 (protein based binder:hardener)
Soy/Urea ratio A1 A2 A3
Tannin/Soy protein ratio 0.50 1.00 1.50
B1 0.00 A1B1
Appearance : yellowish
Viscosity: 0.6 poise
% Solids: 41.22 %
MOR: 52.43 kg/cm2
MOE: - kg/cm2
Thickness swelling: 65.35%
Water absorption: 144.11% A2B1
Appearance :
Viscosity: 1.7 poise
% Solids: 40.99 %
MOR: 92.02 kg/cm2
MOE: 9885.44 kg/cm2
Thickness swelling:40.66 %
Water absorption:146.78 %
A3B1
Appearance :
Viscosity: 4.6 poise
% Solids: 40.28 %
MOR: 68.44 kg/cm2
MOE: 9540.18 kg/cm2
Thickness swelling: 50.68 %
Water absorption: 117.01 %

B2 0.25 A1B2
Appearance : dark brown
Viscosity: 0.7 poise
% Solids: 40.18 %
MOR: 99.64 kg/cm2
MOE: 10518.63 kg/cm2
Thickness swelling: 53.59 %
Water absorption: 104.28 %
A2B2
Appearance : dark brown
Viscosity: 5 poise
% Solids: 40.32 %
MOR: 96.04 kg/cm2
MOE: - kg/cm2
Thickness swelling:88.96 %
Water absorption:103.47 %
A3B2
Very high viscosity/ difficult to stir
B3 0.50 A1B3
Appearance : dark brown
Viscosity: 1 poise
% Solids: 40.46 %
MOR: 72.11 kg/cm2
MOE: 6234.80 kg/cm2
Thickness swelling: 36.84 %
Water absorption:102.16 %
A2B3
No boards prepared due to lumps in the formulation. No proper mixing was executed due to high viscosity.
A3B3
Very high viscosity/ difficult to stir
B4 0.75 A1B4
Appearance : dark brown
Viscosity: 0.8 poise
% Solids: 40.58 %
MOR: 95.44 kg/cm2
MOE: 8508.77 kg/cm2
Thickness swelling: 50.11 %
Water absorption: 110.33 %
A2B4
No boards prepared due to lumps in the formulation. No proper mixing was executed due to high viscosity.

A3B4
Very high viscosity/ difficult to stir
[0097] It is observed from Table 8 that keeping tannin content constant, if soy is increased with respect to urea content, viscosity goes on increasing. [left to right] MOR, MOE and thickness swelling is optimized at soy to urea ratio at 1:1. Keeping urea content constant, increasing tannin content decreases viscosity for same solids. At tannin/soy ratio 0.25 optimized results are obtained with respect to MOR, MOE and thickness swelling under water for 24 hrs. Comparing A1B1 and A1B2, we can observe from A1B2 that tannin improves the overall performance of the protein based binder. A1B2 gives best result among all the above-mentioned experiments and is comparable to UF resin binder.
[0098] Table 9 shows comparative results of different types of binders. Table 9 further shows that protein based binder P with hardener A80 gives good result comparable to UF resin binder. Carboxylation step and addition of shellac further improves the performance and gives most superior result in all aspects.
Table 9: Comparative results of different types of binders
UF resin
Control sample made from ready to use UF powder of make PIDILITE INDUSTRIES LIMITED. By dissolving 70 gm powder in 80 gm water to get required viscosity.
Appearance :
Viscosity: solid powder
% Solids: 100 %
MOR: 120.02 kg/cm2
MOE: 10060.13 kg/cm2
Thickness swelling: 55.2 %
Water absorption: 129.47 %

Description With hardener A80 in ratio 80:20 (protein based binder: hardener) With hardener A40 in ratio 90:10 (protein based binder: hardener)

Protein based binder P This is a random sample with Tannin/soy = 0.31 & Soy/urea =1.29 Appearance :
Viscosity: 4.2 poise
% Solids: 37.94 %
MOR: 113.02 kg/cm2
MOE: 12691.93 kg/cm2
Thickness swelling: 50.06 %
Water absorption: 109.82 %
Appearance :
Viscosity: 4.2 poise
% Solids: 37.94 %
MOR: 75.25 kg/cm2
MOE: - kg/cm2
Thickness swelling: 56.92 %
Water absorption: 136.93 %

Protein based binder A This protein based binder is similar to experiment P which have carboxylation step in acidic medium. Appearance :
Viscosity: 8.6 poise
% Solids: 38.28 %
MOR: 104.49 kg/cm2
MOE: 993.83 kg/cm2
Thickness swelling: 44.82 %
Water absorption: 111.85 %
Not done
Protein based binder B This protein based binder have additional ingredient called as shellac and this is a non urea containing protein based binder. It also contain carboxylation step prior to addition of alkali. Appearance :
Viscosity: 13 poise
% Solids: 39.87 %
MOR: 114.30 kg/cm2
MOE: 13785.99 kg/cm2
Thickness swelling: 45.39 %
Water absorption: 96.30 %
Appearance :
Viscosity: 13 poise
% Solids: 39.87 %
MOR: 68.91 kg/cm2
MOE: 7787.29 kg/cm2
Thickness swelling: 52.27 %
Water absorption: 135.89 %

Protein based binder C This protein based binder has additional ingredient called as shellac. With no urea. Appearance :
Viscosity: 5 poise
% Solids: 38.55 %
MOR: 70.39 kg/cm2
MOE: 11035.94 kg/cm2
Thickness swelling: 34.44 %
Water absorption: 101.83 %
Not done
Protein based binder D A basic soy flour protein based binder denatured with caustic and urea. Appearance :
Viscosity: 3.6 poise
% Solids: 30.79 %
MOR: 65.22 kg/cm2
MOE: 8666.71 kg/cm2
Thickness swelling: 74.69 %
Water absorption: 172.09 %
Not done
[0099] Table 10 shows results of different formulations of protein based binder with hardener A40 (isocyanate) in ratio 90:10 (protein based binder:hardener). It is observed from Table 10 that for hardener A40, going down from A1B1 to A1B4 it is found that increase in tannin content increases MOR but when it comes to thickness swelling A1B3 is superior to UF. Further, soy to urea in ratio 1:1 gives good result in the above table. Except MOR it is superior in all aspects than UF. From above observations it may be concluded that protein based binder with hardener A80 gives better result than with hardener A40. Use of carboxylation and use of shellac in the present formulations may improve the performance of the protein based binder product further.
Table 10: Results of different formulations of protein based binder with hardener A40 (isocyanate) in ratio 90:10 (protein based binder:hardener).
Soy/Urea
ratio A1 A2 A3
Tannin/Soy protein
ratio 0.50 1.00 1.50
B1 0.00 A1B1
Appearance : yellowish
Viscosity: 0.6 poise
% Solids: 41.22 %
MOR: 54.2 kg/cm2
MOE: - kg/cm2
Thickness swelling: 68.8 %
Water absorption: 169.13 %
A2B1
A3B1

B2 0.25 A1B2
Appearance : dark brown
Viscosity: 0.7 poise
% Solids: 40.18 %
MOR: 62.63 kg/cm2
MOE: - kg/cm2
Thickness swelling: 62.55 %
Water absorption: 127.95 %
A2B2
Appearance : dark brown
Viscosity: 5 poise
% Solids: 40.32 %
MOR: 91.27 kg/cm2
MOE: 8791.73 kg/cm2
Thickness swelling: 48.94 %
Water absorption: 117.50 %
A3B2
B3 0.50 A1B3
Appearance : dark brown
Viscosity: 1 poise
% Solids: 40.46 %
MOR: 78.29 kg/cm2
MOE: - kg/cm2
Thickness swelling: 49.11 %
Water absorption: 136.47%
A2B3
A3B3
B4 0.75 A1B4
Appearance : dark brown
Viscosity: 0.8 poise
% Solids: 40.58 %
MOR: 88.03 kg/cm2
MOE: - kg/cm2
Thickness swelling: 59.18 %
Water absorption: 158.25 %
A2B4
A3B4
:
[00100] Further based on the above experiments it may be observed that ratio of urea with respect to soy protein plays important role in maintaining viscosity of final protein based binder. The optimum ratio of urea to soy is 1:1 so that maximum advantage over properties is obtained. Tannin plays an important role in maintaining low viscosity for same solids. In the experiments with hardener A80 we can see that A1B2 and A2B2 give highest values of MOR, MOE. A1B2 is comparable to UF in water absorption and thickness swelling. So the optimization of tannin/soy is 0.25 and for soy/urea is 1. Looking at experiment P (Tannin to soy = 0.31 & Soy/urea =1.29) gives similar result as of Urea Formaldehyde experiment (UF). From the comparison of results with UF, P, A, B, C, D with hardener A80, we conclude that modulus of rupture increases as we add shellac to the system. Also thickness swelling and water absorption properties are improved with shellac. Removing urea from the system increases the viscosity but it doesn’t harm the final properties. Carboxylation step also improves overall performance. Similar trend is observed with experiments with hardener A40 but results are inferior to UF and other experiments with A80. From the pot life study it is observed that there is increase in viscosity with time. Pot life of protein based binder with hardener A40 is not more than 6 hours for this application. Protein based binder with hardener A80 gives pot life of about 8 to 10 hours. For the experiment of using protein based binder P with hardener A80, boards were prepared at 3 different press time intervals, it is found that optimum curing time at a particular pressure and temperature is 10 minutes.
[00101] Although implementations for processes for preparing a protein based binder and processes for preparing wood based product, compositions of a protein based binder have been described in language specific to features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as examples of implementations for processes for preparing a protein based binder and processes for preparing wood based product, compositions of a protein based binder.
[00102] In view of the variety of embodiments of the present disclosure, it will be appreciated that various modifications or changes can be made in the preferred embodiments without departing from the principle of the invention. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein. It is to be particularly understood that the former descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. ,CLAIMS:WE CLAIM:
1. A process for preparing a protein based binder; the process comprises denaturing of a proteinaceous material by cooking the proteinaceous material in presence of water, an alkaline agent, a urea and a polyphenolic compound, at a temperature range of 40 to 150 deg C.

2. The process of claim 1, wherein a reactive diluent is added to denature the proteinaceous material and the reactive diluent is selected from a glycerol (glycerin), an ethylene glycol, a propylene glycol, or a neopentyl glycol.

3. The process of claim 1, wherein a boron compound is added to denature the proteinaceous material and the boron compound is selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid.

4. The process of claim 1, wherein the proteinaceous material is a soy protein and the soy protein is in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans.

5. The process of claim 1, wherein the proteinaceous material comprises at least 20% of carbohydrates by weight.

6. The process of claim 1, wherein the polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).

7. The process of claim 1, wherein the alkaline agent selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, or ammonia solution.

8. The process of claim 1, wherein the proteinaceous material is denatured for a period of ranging from 15 to 500 minutes.

9. The process of claim 4, wherein ratio of addition of the soy protein with the polyphenolic compound such as tannin is in a range of 1 to10.
10. The process of claim 4, wherein a ratio of the urea with the soy protein is in a range of 3:1 to 1:3.by weight.
11. The process of claim 4, wherein the alkaline agent is added in 10 to 50 % of the soy protein by weight.

12. A process for preparing a protein based binder, the process comprises:
carboxylating a proteinaceous material by esterification of the proteinaceous material with a carboxylating agent to produce a carboxylated proteinaceous material;
denaturing of the carboxylated proteinaceous material by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, and a polyphenolic compound, and a natural resin such as shellac at a temperature range of 40 to 150 deg C.

13. The process of claim 12, wherein the proteinaceous material is carboxylated in acidic medium.

14. The process of claim 12, wherein the carboxylating agent is a dicarboxylic acid, and the dicarboxylic acid is selected from a group consisting of a succinic acid, an oxalic acid, a malonic acid, an adipic acid, and a azealic acid.

15. The process of claim 12, wherein a protonating agent is added at a temperature range of 20 to 60 deg C, and wherein the protonating agent is a diluted strong acid or a weak acid.

16. The process of claim 12, wherein the natural resin is selected from a group consisting of shellac, rosin, frankincense, or rosin derivatives.

17. The process of claim 12, wherein the proteinaceous material is carboxylated at a pH ranging from 1 to 6.

18. The process of claim 12, wherein the proteinaceous material is a soy protein and the soy protein is in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans.

19. The process of claim 12, wherein the polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).

20. The process of claim 12, wherein the proteinaceous material is added at temperature range of 20 to 60 deg C.

21. The process of claim 12, wherein a boron compound is added to denature the proteinaceous material and the boron compound is selected from sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, or a salt of boric acid.

22. A composition of a protein based binder comprising a reaction product of:
a) water in a range of 50 to 60 weight parts;
b) a proteinaceous material in a range of 10 to 17 weight parts;
c) an alkaline agent in a range of 1 to 4 weight parts;
d) urea in a range of 8 to 12 weight parts, and e) a polyphenolic compound in a range of 2 to 8 weight parts.

23. The composition of claim 22, comprises a reactive diluent selected from a group consisting of a glycerol (glycerin), an ethylene glycol, a propylene glycol, and a neopentyl glycol.

24. The composition of claim 22, comprises a boron compound selected from a group consisting of sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, and a salt of boric acid.

25. The composition of claim 22, wherein the proteinaceous material is a soy protein and the soy protein is in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans.

26. The composition of claim 22, wherein the polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).

27. The composition of claim 22, wherein the alkaline agent selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, or ammonia solution.

28. The composition of claim 22, comprises a defoamer, an emulsifier, and a biocide in a range from 0.1 to 10 % w/w of the protein based binder.

29. A composition of a protein based binder comprising a reaction product of:
a) water in a range of 50 to 60 weight parts;
b) a proteinaceous material in a rage of 14 to 50 weight parts;
c) a carboxylating agent in a range of 2 to 4 weight parts;
d) an alkaline agent in a range of 1 to 4 weight parts; and
e) a polyphenolic compound in a range of 2 to 8 weight parts and f) a natural resin such as shellac in a range of 2 to 5 weight parts.

30. The composition of claim 29, comprises a reactive diluent selected from a group consisting of a glycerol (glycerin), an ethylene glycol, a propylene glycol, and a neopentyl glycol.

31. The composition of claim 29, comprises a boron compound selected from a group consisting of sodium borate, sodium borohydride, sodium tetra borate, disodium tetraborate, and a salt of boric acid.

32. The composition of claim 29, wherein the proteinaceous material is a soy protein and the soy protein is in a form of soy flour, a soy concentrate, or a soy protein isolate obtained from soy beans.

33. The composition of claim 29, wherein the polyphenolic compound is selected from a group consisting of tannin, residol, cardanol, or cashew nut shell liquid (CNSL).

34. The composition of claim 29, wherein the alkaline agent selected from sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, or ammonia solution.
35. The composition of claim 29, wherein the carboxylating agent is a dicarboxylic acid, and the dicarboxylic acid is selected from a group consisting of a succinic acid, an oxalic acid, a malonic acid, an adipic acid, and a azealic acid.

36. The composition of claim 29, comprises a protonating agent, and wherein the protonating agent is a diluted strong acid or a weak acid.

37. The composition of claim 29, comprises a defoamer, an emulsifier, and a biocide in a range from 0.1 to 10 % w/w of the protein based binder.

38. A method for making a wood based product, the method comprising:
preparing a mixture of a protein based binder and a cross linking agent, wherein the protein based binder is prepared by a process comprising denaturing of a proteinaceous material by cooking the proteinaceous material in presence of water, an alkaline agent, a urea and a polyphenolic compound, at a temperature range of 40 to 150 deg C to prepare the protein based binder;
applying the mixture to wood material or agricultural waste or a combination thereof to make a wood based product.

39. The method of claim 38, comprises mixing the protein based binder and the cross linking agent in a ratio of 95:5% w/w.

40. A method for making a wood based product, the method comprising:
preparing a mixture of a protein based binder and a cross linking agent, wherein the protein based binder is prepared by a process comprising:
carboxylating a proteinaceous material by esterification of the proteinaceous material with a carboxylating agent to produce a carboxylated proteinaceous material;
denaturing the carboxylated proteinaceous material by cooking the carboxylated proteinaceous material in presence of water, an alkaline agent, and a polyphenolic compound, and a natural resin such as shellac at a temperature range of 40 to 150 deg C to prepare the protein based binder;
applying the mixture to a wood material or a agricultural waste or a combination thereof to make a wood based product.

41. The method of claim 40, comprises mixing the protein based binder and the cross linking agent in a ratio of 95:5% w/w.