Description:
Field of the invention:
The present invention relates to a composition comprising vegetable oil polymers suitable for personal care products and a process of preparing thereof. More particularly, the process of making homopolymers of Tung seed oil in a controlled way in the presence of esters that are derived from bio-renewable raw materials, is disclosed.

Background of the invention:
Tung seed oil (Aleurites fordii, Vernicia fordii family: Euphorbiaceae) also known as China wood oil, is widely used for its multiple industrial applications. It is used as water-proof protective coat for wooden surfaces. It is also used as anti-corrosion and anti-rust coating for the protection of metal surfaces from corrosion and rusting. It is also an important raw material for the manufacture of paints and inks.
All the above-mentioned applications are derived for its property of being a fast-drying oil. When it is applied to the surface, the atmospheric oxygen (auto-oxidation) reacts with the oil to convert the oil layer into a hard polymeric film, which ultimately provides protection to the wood (or any other surface) from degradation de to external factors and imparts the property of resisting or repelling water. The mechanism for ‘drying/curing’ involves formation of ethereal linkages (oxygen inserts between C and H of the carbon next to the double bond to form hydroxy peroxide) between the alkyl chains of the triglyceride, which results in intra and inter crosslinking to form a polymeric network. This polymeric network on the surface of the substrate appears as a film (Ned A. Porter, Sarah E. Caldwell, Karen A. Mills "Mechanisms of free radical oxidation of unsaturated lipids" Lipids 1995, volume 30, Pages 277-290). Some oils dry faster (the ones with dienic double bonds, linseed or tung oil) than others. The drying mechanism purely involves the involvement of oxygen to form the ethereal linkages between two alkyl chains that serve as crosslinks to create the macromolecular structure.
However, there is another way to create macromolecular structure from oils, in total absence of oxygen. This involves the unsaturated alkyl chains of the vegetables triglyceride oils that undergo heat induced pericyclic reaction of 4+2 cycloaddition and results in the formation of macromolecular structure. The process is referred to as ‘telomerization’ and usually carried out at very high temperatures of around 300 ℃ in the absence of oxygen using traces of water vapor as catalyst (Landis et. al.; US Pat 5229,023 (1993). The ‘telomerized’ vegetable oils are used as extreme pressure lubricant additives to prevent wear of the metallic parts of machines. For making such ‘extreme pressure’ lubricant additives, triglycerides vegetable oils with varying degree of polyunsaturation, for example, lower degree of polyunsaturation in rapeseed oil and higher degree of polyunsaturation in corn or safflower seed oil. US ‘023 teaches telomerization of corn, crambe, meadowfoam, rapeseed, safflower, sunflower, cotton seed, linseed, olive, soyabean and peanut oil. US ‘023, only teaches the telomerization of selected triglyceride oils and its application as lubricant additive.
For personal care applications, a copolymer of two vegetable oils namely, Tung seed oil and Canola oil (or rapeseed oil, Brassica napus) is offered as ‘Glossmer L-6600’ manufactured by International Lubricants, USA and by Tri-K Industries, USA with the trade name of ‘PhytoVieDefense’. These products containing copolymers of vegetable oils namely, rapeseed oil and Tung seed oil, are used by the personal care industry for a variety of applications such as a fragrance fixative, a booster of sun protection in sunscreen formulations. European patent application (EP4429630 A1 by NAOS Institute of Life Science) teaches the use of such copolymer of vegetable oils for solubilizing UV-absorbers and deposition of such UV-absorbers. Its hydrophobic film-forming property is exploited in imparting ‘water resistance’ in suncare formulations. Generally, this commercial offering of vegetable oil based natural film former is deployed for moisturizing of the skin and hair surface by way of occlusion and for general protection of skin and hair from the environmental assault. Anti-pollution compositions of CN 108498393 (by Guangzhou Liby Enterprise, 2017) claim hair surface protection by the film's physical barrier. It is reported to prevent any absorption of pollutants by the hair surface. It is also said to impart and improve the gloss and shine (Lip Care), hence the trade name GlossamerTM L-6600. The tradename PhytoVieDefense seems to suggest its ‘phyto’ origin and the film-forming properties that defend the substrate from the external onslaught of various factors, pollutants from the environment and as well heat treatment during curling of hair by hot iron. EP2886162A1 (Henkel, 2014) teaches the use of vegetable oil-based polymers for solubilization and deposition of ‘actives’ on hair surface.
The copolymer (CAS No185323-46-0) of Tung seed oil (Aleurites fordii, CAS No 8001-20-5) and rapeseed oil (Brassica Campestris, CAS No. 8002-13-9) for personal care and is registered with ECHA (EC No 606-051-0), the European regulatory agency. According to ECHA website (https://echa.europa.eu/substance-information/-/substanceinfo/100.119.260), the REACH registered copolymer is described as a variable composition made up of three components, namely, Tung oil, Rapeseed oil inter-crossed linked and intra-crossed linked triglycerides of the two vegetable oils and unpolymerized free oils. According to the ECHA website, it is reported as a complex product and not a well-defined composition.
Thus, the copolymer of Tung seed oil and canola oil suffers from two major limitations, limited shelf life (because of resultant composition as described above) and poor sensory performance. The use of human consumable canola oil for the creation of copolymer with Tung seed oil is also a major concern.
The major drawback of these commercial offerings (copolymer of Tung seed oil and canola oil) is the product's instability and limited shelf life. This is due to the presence of free unpolymerized vegetable oils in commercially available products. The unpolymerized oil, particularly Tung seed oil, a fast-drying oil, undergoes rapid autooxidation and subsequent ether linkage formation between the alkyl chains of triglyceride. This results in crusty layer formation on the surface and gel-like formation in bulk of the copolymer material, ultimately rendering material useless for personal care applications. In many cases the material becomes unpourable, and the sticky jelly can’t be removed from the container. Thus, the copolymer and perhaps free unpolymerized Tung seed oil turn the whole product into intractable polymeric material over time (due to reaction with atmospheric oxygen), the characteristic property of drying oils. (Printing Ink Technology by E. A. Apps; page 14, Publisher: Leonard Hills Books Limited, London, 1958). Tung seed oil is used to protect the surfaces from environmental onslaught that includes rain, sun, pests and salt water of sea (for example, wooden cricket bats or musical instrument are protected by applying Tung seed oil or linseed oil that forms protective hard film by oxidation). The same autooxidation is used to protect wooden parts of boats and ships from salty water of seas. However, this drying (and hardening property) of unpolymerized Tung seed oil in the copolymer and perhaps the copolymer itself makes the commercially offered copolymers of Tung seed oil and canola oil unsuitable for personal care applications when it is deposited on skin and hair surface. Because of this ‘drying and hardening’ properties the sensorial properties of the end formulation meant for either skin or hair are seriously compromised when the film gets exposed to atmospheric oxygen. The hardened film is good for protection and deposition of actives by occlusion, but the sensorial properties are seriously compromised. Also, removing deposited hardened copolymer from hair surface is difficult and resulting in loss of aesthetics at the expense of protective film.
The literature on commercially available copolymers (Glossamer L-6600 or PhytoVieDefense) describes them as ‘unknown variable’ compositions. This seems to indicate uncontrolled polymerization during the creation of copolymer from two vegetable oils. The other concern is the use of Canola oil as one of the two monomers for commercially available copolymers. Canola oil (rapeseed oil) is a valuable nutrient for humans. It is low in saturated fats and good source of Vitamin E and Vitamin K. It is said to have an ideal ratio of Omega-3 and Omega-6 fats and is good for cooking. Yellow mustard (Canola oil, Brassica campestris) is very popular in Indian cuisine.
The present invention therefore addresses the following problems:
1) uncontrolled cross-linking of Tung oil and other oils and thereby generating high molecular weight macromolecules that are cross-linked, and
2) unpolymerized triglyceride oil monomers that limit the shelf-life due to its high reactivity towards atmospheric oxygen (in long term the products become totally useless) and thereby the loss of sensory benefits (in short term, immediately after application) after deploying via skin and care formulations.

Objective of the invention:
It is an objective of present invention to take care of the problems associated with prior art.
It is an objective of the present invention to prepare compositions with homopolymer of Tung seed oil with improved stability.
Another objective of the present invention is to prepare compositions with homopolymer of Tung seed oil with the lower amount of unpolymerized Tung seed oil.
Another objective of the present invention is to prepare compositions with homopolymer of Tung seed oil using ester of saturated fatty acids, green emollient, as a solvent medium for polymerization reaction.
Another objective of the present invention is to prepare compositions with homopolymer of Tung seed oil without the use of edible vegetable oils.
Yet another objective of the present invention is to prepare compositions with homopolymer of Tung seed oil that are completely sourced from bio-renewable raw materials.
Yet another objective of the present invention is to prepare compositions with the homopolymer of Tung seed oil with better sensory performance.

Summary of the invention:
To achieve at least one of the objectives, the present invention, in an aspect, provides a composition comprising:
i. a homopolymer of tung seed oil; and
ii. an ester of saturated fatty acids,
wherein the ratio of the homopolymer of tung seed oil to the ester of saturated fatty acid is between 1:5 and 1:3, and
wherein the viscosity of the composition is in the range of 1000 to 5000 cps measured at 25 ℃, and
wherein the composition has less than 3 % unpolymerized tung seed oil, and
wherein the composition is obtained by a process comprising steps of:
a. heating tung seed oil and a part of an ester of saturated fatty acids in nitrogen atmosphere at 200 to 220 ℃ to obtain a viscous reaction mass;
b. cooling the viscous reaction mass of step (a) to 100 to 120 ℃, and adding the remaining part of the ester of saturated fatty acids; and
c. cooling the reaction mass of step (b) to 25 ℃.
In another embodiment, there is provided a process of producing a composition comprising a homopolymer of tung seed oil and an ester of saturated fatty acids in ratio of between 1:5 and 1:3, said composition having viscosity in the range of 1000 to 5000 cps measured at 25 ℃ and less than 3 % unpolymerized tung seed oil;
wherein the process comprises steps of:
a. heating tung seed oil and a part of an ester of saturated fatty acids in nitrogen atmosphere at 200 to 220 ℃ to obtain a viscous reaction mass;
b. cooling the viscous reaction mass of step (a) to 100 to 120 ℃, and adding the remaining part of the ester of saturated fatty acids; and
c. cooling the reaction mass of step (b) to 25 ℃.
In another aspect, the present invention provides a personal care, beauty and cosmetic formulation comprising the homopolymer of Tung seed oil along with the ester of saturated fatty acids.

Brief description of the figures of the invention:
Figure 1: Figure 1 depicts the sensory evaluation of the composition of the present invention with the market standard.

Detailed description of the invention:
The inventors of the present invention have found a way of controlling the polymerization of Tung seed oil and taking it to completion to create a stable, non-edible vegetable oil-based polymer suitable for personal care applications.
Further the present inventors have found that the homopolymer of tung seed oil, instead of copolymer with other oils (specially edible oil), takes care of the problems encountered by prior art and existing products like instability over a period of time, handling of co-polymers and use of edible oil in personal care products. Further the solvent used for the polymerization reation forms the part of the composition according to present invention and hence, avoids solvent recovery and product purification step. More over it avoids use of edible oil and since the same solvent, which helps in polymerization, is used in the final composition helps in reduction of time and cost.
Tung seed oil is known to be obtained from the seeds of the nuts of Tung tree (Aleurites fordii, Vernicia fordii, family: Euphorbiaceae). It is commercially available and is commonly known as China wood oil. On application, the oil forms a hydrophobic film on the surface when exposed to air due to the reaction of its fatty alkyl chain component with the atmospheric oxygen, forming ether linkages between the doubly bonded carbons of alkyl chains of triglycerides. This intra-molecular (linking of alkyl chains of same triglyceride molecule) or inter-molecular ether linkage is akin to the cross linking of macromolecules in polymer chemistry, ultimately yielding a polymeric film. The typical fatty acids of triglycerides of Tung seed oil comprise of α-Eleostearic acid (CAS 506-23-0) as major component (80-85 %) and the other minor components are Linoleic acid (CAS 60-33-3, 8 to 10 %), Palmitic acid (CAS 57-10-3, 5 to 6 %) and Oleic acid (CAS 112-80-1, 4-5%).
α-Eleostearic acid (ESA) is a poly-unsaturated fatty acid (PUFA) with three double bonds (9 Z, 11E, 13 E) and has a pair of conjugated double bonds that makes it highly reactive. Other than the oil of Tung seeds, ESA also occurs in seeds of Bitter Gourd, consumed by the human race since time immemorial. ESA is reported to possess anti-inflammatory properties (Pubali Dhar et al.; Nanomedicine, vol. 14, No.5, 2019). ESA has been shown to ameliorate (https://doi.org/10.1371/journal.pone.0024031, Bevan et al. August 2011) inflammatory bowel disease in animals via a dietary route. Korean scientists recently reported ESA in cure of breast cancer and established the mechanism of suppression of cancer cell by ESA (Cancer Science, 2010; 101: 396–402).
In an embodiment the ester of saturated fatty acid, used in the composition and process of the present invention, is an esterified product of saturated fatty acids with carbons chain in the range of C8 to C22 and saturated monohydric or polyhydric alcohols with carbon chain in the range of C3 to C22.
In another embodiment, the ester of saturated fatty acid is selected from caprylyl capric triglyceride, coco caprylate, coco caprate, stearyl palmitate, and palmityl stearate or mixture thereof.
In yet another embodiment, the esters of saturated fatty acids are derived from bio-renewable feedstock.
In another aspect, the present invention provides a personal care formulation comprising the homopolymer of Tung seed oil along with the ester of saturated fatty acids at an amount of at least 0.1 to 20% by weight of the personal care formulation.
In an embodiment, the personal care formulation is selected from leave-on formulations like cream, lotion, sunscreen, hair serum, hair conditioner, etc. or rinse-off formulations like shampoo, bodywash, handwash, soaps, etc.

Homopolymerization of Tung seed oil in saturated fatty acid esters
In an embodiment, the homopolymerization of Tung seed oil is mediated through thermal treatment of Tung seed oil in a saturated fatty acid ester. The alkyl chains of polyunsaturated ESA in Tung seed oil (Formula 1) undergoes heat induced 4 + 2 pericyclic reactions that are intramolecular (Formula 2) and intermolecular (Formula 3) to form a network of macromolecules. The progress of this thermal cyclo-addition reaction can be monitored by a drop in the iodine value (number of mg of iodine absorbed by 100 mg of substrate) and an increase in the product's viscosity.

Formula 1 Formula 2

Formula 3
Preferably, to control the cycloaddition reaction, the homopolymerization of the Tung seed oil (CAS 8001-20-5) is carried out in the presence of a green emollient like CCTG (caprylic capric triglyceride, CAS 73398-61-5, Example 1). Preferably, the Tung seed oil and CCTG in the ratio of 4:6 by weight is charged into a reaction vessel. The iodine value of the above mixture is around 70. Preferably, the homopolymerization is achieved at around 205 ℃ under nitrogen (after expelling all air by purging nitrogen) in about 28 hours as monitored by viscosity (3,18, 000 cps at 25 ℃) of the reaction mixture. Preferably, the above reaction mixture is cooled to 100 ℃ and additional quantity of CCTG is added. The whole reaction mixture is then allowed to cool down to room temperature. Preferably, the resultant material (with ratio of CCTG:Tung seed oil homopolymer :: 8:2) has iodine value of 24. The drop in iodine value from 70 to 24 (Example 1a) is a result of homopolymerization of Tung seed oil in the presence of CCTG. The final composition is analyzed for the presence of unreacted Tung seed oil, and it has been estimated to be less than 1 % (Example 1a). The methodology is repeated three more times to confirm the consistency of the process. The average molecular weight of the homopolymer is determined by Gel permeation chromatography (GPC) analysis. It is found to be in the range from 4,00,000 g/mol to 5,00,000 g/mole (Table 2 in Example 1a to Example 1d) and viscosities in the zone 1500 cps to 2000 cps at 25 ℃. Preferably, the other green emollients were used to prepare the composition with homopolymer of Tung seed oil according to the invention. All four compositions (Example 1a to Example 1d) are stable during the six months stability studies at ambient temperature and accelerated stability studies at 40 ℃ for 90 days.

Green Emollients:
In an embodiment, several ‘Green’ emollients have been deployed to conduct homopolymerization of Tung seed oil according to the present invention. Preferably, ‘Green’ emollients deployed in the present invention are synthesized from saturated fatty acids with carbon chain of C8 to C22 and saturated monohydric or polyhydric alcohols with carbon chain of C3 to C22 that are derived from bio-renewable sources. The esterification reaction of such fatty acids and alcohol is affected by ‘Green chemistry’. Example 2 describes heat-induced homopolymerization in the presence of coco caprylate/caprate (CAS 95912-86-0) which is derived from saturated cocofatty alcohol and approx. 1:1 blend of caprylic acid and capric acid. This esterification is affected by enzyme catalyst like commercially available CALB (Candida antartica lipase B). The composition of Example 2 has homopolymer with average molecular weight of 2,41,725 g/mol and overall viscosity of 1556 cps and unpolymerized Tung seed oil around 2.3 %. This is the result of carrying out the homopolymerization for 28 h indicating further scope of fine tuning in terms of reaction time to achieve slightly higher viscosity and lower free unpolymerized Tung seed oil. Another Green emollient is synthesized from 2-ethyl hexanol and stearic acid. Stearic acid is obtained from renewable vegetable oils, whereas 2-ethyl hexanol is derived from ethyl alcohol via fermentation process (www.godavaribiorefineries.com). Bio-derived 2-ethyl hexanol is esterified with stearic acid using lipase enzyme (immobilized enzyme derived from yeast Candida antartica). This green ethyl hexyl stearate is used in Example 3 wherein the final composition with homopolymer of average molecular weight 4,18,456 g/mol, and unpolymerized free Tung seed oil around 1.6 % of total composition, having viscosity of 1110 cps at room temperature.
Another example of homopolymerization in ‘green’ emollient is octadecyl myristate (CAS 22766-83-2), which is again synthesized by lipase catalyst from its constituent saturated fatty alcohol and fatty acid. The details of the analysis of this composition are given in Table 3. Examples 1 to 5 illustrate the use of liquid esters that are made from corresponding saturated fatty acids and alcohols which afford final compositions containing the homopolymer of Tung seed oil as a liquid product of very moderate viscosity, ranging from 1000 cps to 5000 cps. Example 5 demonstrates the process of preparing homopoymer of Tung seed oil in green emolient wherein the the final product provides the composition according to the present invention with a ratio of the homopolymer to the ester of 1:3 and 1:5. Example 6 demonstrates that the process of the present invention can be conveniently carried out in solid esters at room temperature. For example, homopolymerization carried out in hydrogenated triglyceride gives a solid composition at room temperature (Example 6) and also imparts good stability to the composition without compromising the performance of the homopolymer. Ease of incorporation for such composition into a formulation is somewhat compromised since solid esters need warming up depending on their melting points. The process of the present invention can be extended to ‘solid green esters’ like 1,3 propane diol distearate (CAS No 17367-44-1, mp 65-68 ℃) which is made from fermentation derived 1,3 propane diol and vegetable oil derived stearic acid or ethylene glycol distearate (CAS No 627-83-8, mp 65-73 ℃) wherein ethylene glycol is derived from fermentation derived ethyl alcohol. The esterification for such solid esters is catalyzed by immobilized yeast derived lipase which is recycled several times without losing any catalytic efficiency. The advantage of having homopolymer of Tung seed oil in solid esters is not just the infinite stability but these solid esters also bring benefits like pearlizing the formulations (aesthetically appealing) in addition to sensory (emollience and conditioning), moisturization benefits to skin and hair. Emollients are an integral part of skin care products for their important role. The composition of the present invention uses ‘Green’ esters and emollients where both fatty acids and alcohols are derived from bio-renewable feedstocks. In addition to aesthetic, sensory, moisturizing (by occlusion) in creams or lotions, these can be vehicles for key active ingredients such as UV-absorbers in sunscreen formulations. Today’s personal care formulations are designed to offer multiple attributes that go beyond simple soothing and moisturizing effects. Well-moisturized skin is the basic care but in addition to that other benefit agents such as nutrients, vitamins, ceramides, sunscreens, antimicrobials and prebiotics towards skin microbiota are delivered by creams and lotions. The homopolymerization of Tung seed oil is demonstrated with liquid and solid ester-emollients that are ‘Green’. The composition of Example1a is biodegradable as per the OECD 301B protocol. In 28 days, the recorded degradation is 72.00 %.

Process to prepare the compositions with Homopolymer of Tung seed oil
The composition of the present invention preferably comprises a homopolymer of Tung seed oil and an ester of saturated fatty acid. The homopolymer of Tung seed oil is preferably made in a solvent comprising of an ester of saturated fatty acid. Preferably the Tung seed oil and an ester of saturated fatty acid is placed in a closed reaction vessel equipped with overhead stirring and heating mechanisms. Preferably, all the air in the reaction vessel is displaced with nitrogen before initiation of the polymerization. Preferably, the polymerization of Tung oil is affected in absence of oxygen at a temperature of 200 to 220 ℃ in the absence of catalyst. Preferably, the ratio of the Tung seed oil to the solvent is 2:3. The temperature of the reaction is maintained until the viscosity in the range of 3,00,000 to 5,00,000 is achieved. The reaction is also monitored via a drop in the iodine value. Preferably, the iodine value of about 24 is an indication of polymerization of more than 97% of the Tung seed oil. After the homopolymer is formed, confirmed through the drop in iodine value and determination of free Tung oil, the temperature of the reaction mass is reduced to 100 to 110 ℃. Preferably the additional or remaning ester of saturated fatty acid is added at 100 to 110 ℃ to adjust the ratio of the Tung oil polymer to the ester of saturated fatty acid between 1:3 and 1:5. Preferably reaction mass is cooled and the product obtained has a viscosity in the range of 1000 to 5000 cps when measured at room temperature. Preferably, the product obtained is the composition according to the present invention comprising of homopolymer of Tung seed oil and ester of saturated fatty acid in a ratio of between 1:5 and 1:3. Preferably, the composition of the present invention comprises less than 3% of unreacted Tung seed oil.
Preferably the ratio of the homopolymer of Tung seed oil to the ester of saturated fatty acid can be between 1:5 to 1:3, depending upon the end application of the composition of the present invention. When the end application requires to prepare the formulations with lower viscosities the ratio of the homopolymer of Tung seed oil to the ester of saturated fatty acid can be 1:5. On the other hand if the desired viscosity needed for end formulation is higher the ratio of the homopolymer of Tung seed oil to the ester of saturated fatty acid can be 1:3.

Performance of the compositions with homopolymer of Tung seed oil:
As described in the background section, the copolymers of Tung seed oil and canola oil have been reported to deliver actives via personal care formulations (EP4429630 A1, CN 108498393 and EP2886162A1), a representative composition (Example 1) of the present invention is compared with the market composition of copolymer for deposition of actives. The comparison is done via a shampoo formulation using two fragrances, namely, benzyl alcohol and linalyl acetate. A pearly shampoo base is prepared with cocamidopropyl betaine, sodium lauryl ether sulphate, fix amount of fragrance molecule (0.5 % of the total composition) and varying amount of composition of Example 1 (0 % (as blank), 0.5%, 1.0 % and 2.0 %, Example 7, formulations A, B, & C) and composition of copolymer of Tung seed oil and canola oil (2 %, Example 7, Formulation D). The composition of Example 1a has about 20 % homopolymer whereas the market sample (trade name, PhytoVieDefense) of copolymer of Tung seed oil and canola oil has about 22 % copolymer. The polymer content of both compositions is determined by precipitating the polymer using acetone, isolating the polymer and quantifying the same. Fixed quantity of hair strands is treated with a fixed amount of shampoo and water, and hair tress are gently towel-dried following the literature protocol (J. M. Blakeway and M. Seu-Salerno, International Journal of Cosmetic Science, 5, 15-23, 1983). The hair tresses are evaluated for sensory effect by the expert panel. This is followed by olfactory evaluation by the expert panel. The results are presented in table 6. The deposited actives, benzyl alcohol and linalyl acetate, are extracted using hot solvent extraction and quantified by gas chromatography. With the increased amount of usage of compositions of polymers of vegetable oil, the deposition of active proportionately increases. This can be seen from the extracted actives, via solvent extraction, and olfactory evaluation (Table 6 of Example 7). When compared to commercially available co-polymer at same dosage level of 2.0 % (Formulation D of Example ) and composition of Example 1a at 2 % (Formulation C of Example 7), it is observed that the efficiency of the deposition for both actives as well as degree of olfaction are about the same. However, there is perceptible difference in the sensory feel of the treated hair strands wherein shampoo of composition of Example 1a (formulation C) exhibits a superior sensory feel over formulation D.
The sensory aspect is further evaluated by a ‘leave-on’ cream formulation (Formulation E and Formulation F) as per table 7 of Example 8. The composition of Example 1a as well as the market composition of the copolymer of Tung seed oil and canola oil are deployed at 10.0 %.
After application of the cream, the expert panel evaluated the sensory performance on several counts of which tackiness and ease of spreading/ease of pick-up showed the perceptible differences between the two cream formulations (Fig 1, Example 8) wherein composition of Example 1a exhibits perceptibly superior performance compared to market product of PhytoVieDefense. At same % level, the market product of copolymer (Tung seed oil and canola oil) which has high crosslinking and high molecular weight, results in highly viscous products as can be seen by viscosity of 3,40,000 cps (in case of crosslinked co-polymer) against 75,000 cps. Crosslinked high molecular co-polymer results in inferior performance of a cream-like formulation in terms of both sensory as well as ease of application (Example 8, Fig. 1).
Therefore, the composition of the present invention comprsising homopolymer of Tung seed oil along with ester of saturated fatty acids are conveniently manufactured via green process. Also, the composition of the present invention does not contain the edible vegetable oils which is otherwise present in the composition available in the market. Further, the composition of the present invention are stable over the wide range of temperature conditions and does not form the gel like high viscous composition.

Advantages of the present invention over prior art:
The compositions of the present invention offer several advantages and benefits for personal care over the copolymers of Tung seed oil and other unsaturated edible oils (US Pat 5229,023, 1993). Compositions are commercially available for personal care are copolymers of Tung seed oil and Canola oil (Glossamer L6600 and PhytoVieDefense) that are reported to be of unknown variable compositions. These are also reported to be unstable (hence, limited shelf life) and lower biodegradability.
1) Unlike the commercially available copolymers of Tung seed oil and Canola oil, the compositions claimed in the present invention are stable at lower as well as at elevated temperature of 40 ℃. This is due to the overall low content of free Tung seed oil in the final compositions that are based on homopolymers of Tung seed oil.
2) The commercially available co-polymers from the prior art are reported to be of unknown variable composition (ECHA website). This variation in composition is the result of two monomers used in this copolymer having different reactivity and due to two competing processes of homopolymerization vs copolymerization, it is hard to predict a defined outcome of the copolymer formed. This uncertainty and disadvantage have been eliminated in the homopolymer of Tung seed oil of the present invention.
3) The compositions of the present invention are superior in sensory and particularly ease of spreadability of creams and lotions due to the non-tacky nature of the homopolymer as opposed to the extremely tacky nature of the high molecular weight crosslinked copolymer of the prior art. GPC analysis of commercially available copolymers for personal care (Glossamer L6600 and PhytoVieDefense) are found to have an average molecular weight in the zone of 10,00,000 and above whereas the homopolymer of the present invention has a molecular weight in the zone of 4,00,000 to 5,00,000.
4) Ease of preparing formulations of personal care products: Compositions comprising the low molecular weight homopolymer of Tung seed oil are easy to formulate in both ‘leave-on’ and ‘rinse-off’ formulations. In contrast to the crosslinked unwieldy macromolecular structure of copolymers of Tung seed and Rapeseed oils, the compositions of the low molecular weight, non-cross-linked homopolymers of the present invention are easy to formulate in both oil-in-water type of emulsions and easy to solubilize in a water-based surfactant matrix of cleansing formulations.
5) Compositions of the present invention are manufactured using principles of green chemistry, notably, a) renewable non-edible raw materials, b) without any hazardous chemicals or volatile solvents, c) minimum chemical engineering operations, d) quantitative conversion, e) no wastage, 100 % yield, f) 100 % atom economy (no atoms and molecules are lost as by- products) and g) the end-compositions are biodegradable.
6) Unlike the copolymer of Tung seed oil and canola oil of the prior art, the green process of manufacturing homopolymer in the presence of green ester-emollients, is completely controlled and the final compositions are fully characterized by both physical parameters as well as the chemical analysis including the ‘gel permeation chromatography’ to ensure the consistent outcome (see Table 2 and 3 in Example 1). Compared to the existing ill-defined copolymer of the prior art, the compositions of homopolymer of Tung seed oil in green emollient esters are non-tacky, provide superior sensory feel, and excellent stability. Compositions of the present invention are expected to be more biodegradable and ecofriendly due to lesser degree of cross linking and due to low average molecular weight. Finally, the homopolymers of Tung seed oil are easy for deposition of with green ester type emollients.
7) Unlike the copolymer of Tung seed oil and Canola oil of the prior art, the compositions of the present invention are based on the homopolymer of Tung seed oil and do not deploy any edible vegetable oil that is suitable for human consumption.
Provided below are non limiting illustrative examples.

Examples:
Tung seed oil (CAS 8001-20-5) is procured from Guangxi Sinotung Trading Co., Guangxi, China 53002 as pale-yellow oil with sap value of 195, and iodine value of 175. Caprylic capric triglyceride (CCTG, CAS 73398-61-5), 2-Ethyl hexyl stearate (EHS, CAS 22047-49-0), Coco caprylate/caprate (CAS 95912-86-0), Octadecyl myristate (CAS 22766-83-2) are procured from Galaxy Surfactants Limited. The non-glycerol esters are synthesized from corresponding fatty acids and alcohols by yeast-derived lipase-catalyzed esterification at 75 ℃. Saturated triglycerides (CAS 91082-37-0, HSFO) was procured from Gokul Agri International Ltd. (www.gokulagri.com) Ahmedabad, Gujrat, India.
Table 1: Saturated esters of fatty acids as solvent medium for preparing homopolymer of Tung seed oil.
Molecule CCTG CCC EHS ODM HSFO
CAS Registry 73398-61-5 95912-86-0 22047-49-0 22766-83-2 91082-37-0
Nature Colorless liquid Colorless liquid Colorless liquid Colorless liquid Off-white solid, m p: 68-70 ℃
Acid value < 1.0 < 1.0 < 1.0 < 1.0 < 1.0
Sap value 332 170 155 108 191

Substantivity and Olfactory Evaluation:
Hair preparation and application protocol for substantivity evaluation of fragrance molecules are done according to protocol prescribed by Seu-Salerno et. al. in International Journal of Cosmetics Science, 15-23, (1983).
Briefly, unbleached (virgin) Asian black hair tresses of 10 cm average length are washed with 10% sodium lauryl ether sulphate solution and rinsed until no sign of surface activity remained in the rinse. The hair tresses are air-dried.
The air-dired hair tresses (10 g) are rinsed with tap water at 37 ℃ and squeezed manually to remove the excess water, the final weight is adjusted with water to 20 g. To this, 1.5 g of shampoo containing 0.5% (w/w) of perfume (linalyl acetate or benzyl alcohol) is added, and the hair is massaged for 1 minute to achieve an even distribution of lather. It is then allowed to settle for 2 minutes further and rinsed with running tap water for 1 minute. Finally, it is squeezed damp dry, and part of it (1.0 g) is taken for perfume extraction using methanol as a solvent, whereas the remaining hair sample is used for olfactive evaluation by a panel of trained experts using a four-point scale: +, ++, +++ and ++++.

Gel Permeation Chromatography (for determination of average mole weight) is carried out on the Agilent 1260 multidetector system using the following conditions.
Column: PLgel Mixed- D with a guard column.
Temperature: 35°C
Eluent/Mobile phase: THF (flow rate, 1ml/min),
Detector: Refractive Index
Injection Volume: 100μL (sample concentration 10 mg/ml),
Polystyrene Standards: 600000, 170000, 90000, 47500, 23000, 9000, 2980 & 2000.
Estimation of unpolymerized Tung seed oil in the compositions of Example 1 to 6 is determined by dissolving a known quantity of sample in acetone to precipitate the polymer and separating acetone from the precipitated polymer. Acetone is removed by rotary evaporation, and the residue is reextracted by n-hexane. Iodine value of residue after evaporation of hexane is related to % of free tung seed oil, assuming Iodine value of 100 % Tung seed oil to be 175. The iodine value of hexane extracted materials from Example 1 to 6 is less than 6.0.
The biodegradability of compositions of the present invention are evaluated as per the guidelines of OECD 301B.

Example 1: Synthesis of homopolymer of Tung seed oil in caprylic capric triglyceride and composition comprising homopolymer of Tung seed oil and caprylic capric triglyceride
Example 1a: A stirred mixture of caprylic capric triglyceride (420 g) and Tung seed oil (280 g) (Ratio 1.5 : 1) is heated in total absence of oxygen, without any additive, under nitrogen atmosphere at 205 to 215 ℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 °C. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case, viscosity is 3,18,600 cps at 25 °C after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass, additional caprylic capric triglyceride (700 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1400 g, 100%, taking sample qty into consideration) has the following analysis. The ratio of homopolymer of Tung seed oil to caprylic capric triglyceride is 1:4.
Table 2: Analysis of the composition with homopolymer of Tung seed oil and caprylic capric triglyceride as per example 1a
Color (on Gardner scale) 3.9
Viscosity at 25 ℃ #3 rpm 40 (LVT) cps 1677
Iodine value 24
Sap value 315
Wt. avg. mole weight (GPC) 4,05,258 g/mol
Unpolymerized Tung seed oil 0.9

Example 1a is repeated three more times to check the precision control of polymerization.
Table 3: Repetition of method to prepare the composition with homopolymer of Tung seed oil and caprylic capric triglyceride of Example 1a
Examples Average molecular weight of the homopolymer of the composition Viscosity of the composition at 25 ℃ #3 rpm 40 (LVT), cps
Example 1a 4,05,258 g/mol 1677
Example 1b 4,17,200 g/mol 1523
Example 1c 4,45,133 g/mol 1800
Example 1d 4,62,855 g/mol 1920

All four compositions (Example 1a to Example 1d) are found to be stable for six months at ambient temperature and during the accelerated stability study at 40 ℃ for 90 days.

Example 2: Synthesis of homopolymer of Tung seed oil in coco caprylate/ caprate and composition comprising homopolymer of Tung seed oil and coco caprylate/ caprate
A stirred mixture of coco caprylate/caprate (420 g) and Tung seed oil (280 g) is heated in total absence of oxygen, without any additive and under nitrogen atmosphere at 205 to 215℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 deg ℃. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case viscosity is 3,35,600 cps at 25 ℃ after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass additional coco caprylate/caprate (700 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1402 g, 100%, taking sample qty into consideration) has the analysis as per table 4.

Example 3: Synthesis of homopolymer of Tung seed oil in 2-ethyl hexyl stearate and composition comprising homopolymer of Tung seed oil and 2-ethyl hexyl stearate
A stirred mixture of ethyl hexyl stearate (420 g) and Tung seed oil (280 g) is heated in total absence of oxygen, without any additive and under nitrogen atmosphere at 205 to 215℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 °C. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case viscosity is 3,43,800 cps at 25 °C after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass additional ethyl hexyl stearate (700 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1398 g, 100%, taking sample qty into consideration) has the analysis as shown in table 4.

Example 4: Synthesis of homopolymer of Tung seed oil in octadecyl myristate and composition comprising homopolymer of Tung seed oil and octadecyl myristate
A stirred mixture of octadecyl myristate (420 g) and Tung seed oil (280 g) is heated in total absence of oxygen, without any additive and under nitrogen atmosphere at 205 to 215℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 °C. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case viscosity is 3,55,000 cps at 25 °C after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass additional octadecyl myristate (700 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1404.5 g, 100%, taking sample qty into consideration) is analyzed and the results are presented in table 4.

Example 5: Synthesis of homopolymer of Tung seed oil in caprylic capric triglyceride and composition comprising homopolymer of Tung seed oil and caprylic capric triglyceride in ratio of 1:3 and 1:5.
Example 5a: A stirred mixture of caprylic capric triglyceride (420 g) and Tung seed oil (280 g) is heated in total absence of oxygen, without any additive, under nitrogen atmosphere at 205 to 215 ℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 °C. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case, viscosity is 3,28,600 cps at 25 °C after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass, additional caprylic capric triglyceride (420 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1124 g, 99%, taking sample quantity into consideration) is analyzed and the results are presented in table 4. The ratio of homopolymer of Tung seed oil to caprylic capric triglyceride is 1:3 (25% of homopolymer by weight of the composition according to present invention).
Example 5b: A stirred mixture of caprylic capric triglyceride (420 g) and Tung seed oil (280 g) is heated in total absence of oxygen, without any additive, under nitrogen atmosphere at 205 to 215 ℃ for about 28 hours. The progress of homopolymerization is monitored by measuring the viscosity of the reaction mass at 25 °C. Homopolymerization is stopped when viscosity reaches in the zone 3,00,000 to 4,00,000 cps. In this case, viscosity is 3,22,600 cps at 25 °C after 28h.
The reaction mass is cooled to 100 ℃ under continuous stirring and to this mass, additional caprylic capric triglyceride (980 g) is added. On cooling to room temperature, vitamin E acetate (4.5 g) is added and mixed well. The resultant homogeneous transparent mass (1680 g, 99%, taking sample quantity into consideration) is analyzed and the results are presented in table 4. The ratio of homopolymer of Tung seed oil to caprylic capric triglyceride is 1:5 (16.67% of homopolymer by weight of the composition according to present invention).
Table 4: Analysis of the composition with homopolymer of Tung seed oil and ester of saturated fatty acids, as per example 2 to 5
Parameters of Analysis Example 2 Example 3 Example 4 Example 5a Example 5b
Color (on Gardner scale) 3.1 3.7 2.8 3.5 3
Viscosity at 25 ℃ #3 rpm 40 (LVT) cps 1556 1110 1584 4000 1000
Iodine value 27 25.8 26.4 25.9 26.2
Sap value 183 158 128 287 308
Wt. avg. mole weight (GPC) 2,41,725 g/mol 4,18,456 g/mol 3,54,169 g/mol 3,45,124 g/mol 4,12,211 g/mol
Unpolymerized Tung seed oil 2.3 % 1.6% 1.3% 1.4% 1.5%

Example 6: Homo-polymerization of Tung seed oil in hydrogenated triglyceride and composition comprising homopolymer of Tung seed oil and hydrogenated triglyceride
A mixture of hydrogenated triglyceride (420.0 g) and Tung seed oil (280.0 g) under nitrogen blanket is stirred at 205 -210 ℃ for 28 hours. (in complete absence of air and without any additive). The reaction is continued for 28 h (iodine value of 48.5). The reaction mass is then cooled to 150 ℃ under stirring, and additional hydrogenated triglyceride (700 g) is added and stirred until homogeneous. It is further cooled and flaked at 120 ℃.
The analysis of the resultant of off-white flakes (1391 g) is given below.
Table 5: Analysis of the composition with homopolymer of Tung seed oil and hydrogenated triglyceride as per example 5
Appearance Off-white solid flakes
Metling range 60 to 70 ℃
Iodine value 21.70
Sap value 188
Wt. avg. mole weight (GPC) 161751 g/mol
Iodine value 55.62
Unpolymerized Tung seed oil 1.9 %

Example 7: Enhanced deposition of actives using the composition of Example 1a in a shampoo formulation
Table 6: Comparison of the composition of the present invention (Example 1a) and market standard for the deposition of active in shampoo formulation
Blank (A) (B) (C) (D)
Ingredients Weight % Weight % Weight % Weight % Weight %
Phase A
Water q.s. to 100 q.s. to 100 q.s. to 100 q.s. to 100 q.s. to 100
Cocamidopropyl betaine (36 %) 8 8 8 8 8
Sodium lauryl ether sulphate (28 %) 40 40 40 40 40
Sodium chloride 0.4 0.4 0.4 0.4 0.4
Phase B
Polyglyceryl-3 Oleate 2 2 2 2 2
Ethylene glycol distearate 1 1 1 1 1
Phase C
Composition of Example 1a 0.0 0.5 1.0 2.0 -
Market sample of copolymer of Tung seed oil and canola oil (PhytoVieDefense) - - - - 2.0
Linalyl Acetate (or Benzyl alcohol) 0.5 0.5 0.5 0.5 0.5
Analysis
pH (5 %, in water) ~5.5 ~5.5 ~5.5 ~5.5 ~5.5
Viscosity in cps (formulations with Linalyl acetate) 14,000 13,130 12,900 12,600 12,565
Linalyl acetate deposited mg/g of hair 0.07 0.045 0.13 0.22 0.20
Olfactory evaluation (Linalyl acetate) + + ++ +++ +++
Benzyl alcohol deposited mg/g of hair 0.03 0.05 0.07 0.12 0.12
Olfactory evaluation (Benzyl alcohol) + ++ +++ ++++ ++++
Sensory evalation + ++ ++ ++++ +++

All ingredients of Phase B are mixed and heated slowly to 75 oC under continuous stirring. To a stirred Phase A, Phase B is added and mixed thoroughly till it becomes homogeneous solution. The whole mass is then cooled to room temperature and the pH is adjusted with citric acid to 5.5. This is followed by the addition of Linalyl Acetate (or Benzyl alcohol) and the composition of Example 1a (or Market composition, PhytoVieDefense) under continuous stirring to get homogeneous shampoo with viscosity of around 12,000 cps. There is insignificant change in the rheology of aqueous shampoo formulation with the gradual increase in the composition of Example 1a, going from 0.5 to 2.0 %.
To evaluate the substantivity of the composition of the present invention, the unbleached (virgin) Asian black hair tresses, averaging 10 cm in length, are used to determine substantivity and olfactory effects. These tresses are washed with a 10% sodium lauryl ether sulfate solution, thoroughly rinsed until no surface activity remains, and then air-dried. The hair tresses (10 g) are rinsed with tap water at 37 ℃ and squeezed manually to remove the excess water, the final weight is adjusted with water to 20 g. To this, 1.5 g of shampoo containing 0.5% (w/w) of perfume (linalyl acetate or benzyl alcohol) is added, and the hair is massaged for 1 minute to achieve even distribution of lather. It is then allowed to settle for 2 minutes further and rinsed with running tap water for 1 minute. Finally, it is squeezed damp dry, and part of it (1.0 g) is taken for perfume extraction using hot methanol (50 ml, reflux for one hour). The methanol extract is transferred to volumetric flask and then used for quantification of extracted fragrance using HPLC coupled with UV-detector at 210 nm. The mobile phase is acetonitrile-water with 0.1 % phosphoric acid and the stationary phase is reversed phase column C18 (Syncronis C18, 250 × 4.6mm) by Thermo Scientific.
Olfactive Evaluation:
The hair tresses treated with the above four shampoo formulations (A to D), are evaluated by a panel of 10 experts. The olfactive evaluation is done on wet hair immediately after rinsing and after air drying for 30 mins. The summary of the results is mentioned in the table 6 for Linalyl acetate and Benzyl alcohol using a four-point scale, viz. Strong (++++), Medium (+++), Weak (++), faint (+)
Example 8: Sensory evaluation via a cream formulation:
Two cream formulations are prepared for comparison of sensory effect, one with the composition of Example 1a (Formulation E) and the other with market product, PhytoVieDefense (Formulation F), a copolymer of Rapeseed oil and Tung seed oil.
Table 7: Sensory evaluation of the cream formulation with composition of present invention and market sample
Phase A Formulation E Formulation F
Water To make 100 % To make 100 %
Disodium ethylene diamine tetra acetic acid 0.10 % 0.10 %
Phenoxyethanol (and) Benzoic Acid (and) Capryloyl Glycine (and) Undecylenoyl Glycine 1.0 % 1.0 %
Phase B
Cetostearyl Alcohol 3.5% 3.5 %
Stearic acid 5.0% 5.0%
Composition of Example 1a 10.0 % -
Market product (PhytoVieDefense) - 10.0 %
Phase C
Sodium hydroxide solution pH 6.0-6.2 pH 6.0-6.2

Procedure
The mentioned quantity of Phase A and Phase B ingredients is weighed in a vessel separately and both the phases are heated to 70-75◦C. To a Phase A, Phase B is added and homogenised (4000-5000 RPM) while cooling the mass down to ambient temperature. The Sodium Hydroxide solution (Phase C) is used to adjust the pH of the resultant cream & pH is adjusted to 6.0 to 6.2 to give a fine textured opaque cream with viscosity of 75,000 cps (in case Composition of Example 1a) and 3,40,000 cps in case of market product, PhytoVieDefense.
The results of sensory evaluation of the formulations is presented in Figure 1.
, Claims:
1. A composition comprising:
i) a homopolymer of tung seed oil; and
ii) an ester of saturated fatty acids,
wherein the ratio of the homopolymer of tung seed oil to the ester of saturated fatty acid is between 1:5 and 1:3, and
wherein viscosity of the composition is in the range of 1000 to 5000 cps measured at 25 ℃, and
wherein the composition has less than 3 % unpolymerized tung seed oil, and
wherein the composition is obtained by a process comprising steps of:
a. heating tung seed oil and a part of an ester of saturated fatty acids in nitrogen atmosphere at 200 to 220 ℃ to obtain a viscous reaction mass;
b. cooling the viscous reaction mass of step (a) to 100 to 120 ℃, and adding remaining part of the ester of saturated fatty acids; and
c. cooling the reaction mass of step (b) to 25 ℃.

2. The composition as claimed in claim 1, wherein the ester of saturated fatty acid is an esterified product of saturated fatty acids with carbon chain in the range of C8 to C22 and saturated monohydric or polyhydric alcohols with carbon chain the range of C3 to C22.ss

3. The composition as claimed in claims 1 and 2, wherein the ester of saturated fatty acid is selected from caprylyl capric triglyceride, coco caprylate, coco caprate, stearyl palmitate, and palmityl stearate or mixture thereof.

4. The composition as claimed in claims 2 and 3, wherein the ester of saturated fatty acid is derived from bio-renewable feedstock.

5. A process of producing a composition comprising a homopolymer of tung seed oil and an ester of saturated fatty acids in ratio of between 1:5 and 1:3, said composition having viscosity in the range of 1000 to 5000 cps measured at 25 ℃ and less than 3 % unpolymerized tung seed oil,
wherein the process comprising steps of:
a) heating tung seed oil and a part of an ester of saturated fatty acids in nitrogen atmosphere at 200 to 220 ℃ to obtain a viscous reaction mass;
b) cooling the viscous reaction mass of step (a) to 100 to 120 ℃, and adding the remaining part of the ester of saturated fatty acids; and
c) cooling the reaction mass of step (b) to 25 ℃.

6. A personal care formulation comprising homopolymer of Tung seed oil and ester of saturated fatty acids at an amount of 0.1 to 20% by weight of the personal care formulation.