For Further Information Please Contact

Head, Business Processes Division,
CLRI, Adyar, Chennai 600 020.
Tel.:+91 44 2491 5238
email : e-mail :bpdclri@yahoo.com;
bpd@clri.res.in

Leather Chemicals

Fatliquor
Tanning Auxiliary
Mineral Syntan
Pretanning auxiliaries
Chemicals for hazardous substance free leather
Vegetable / Non - Protein Based Syntan
Protein Based Syntan
Dyeing auxiliaries
Antifungal composition
Finishing Auxiliaries
Adhesives

An improved process for the preparation of fatliquor for application in leather processing
Disclosed herein is an improved process for the preparation of fatliquor for application in leather processing. The oil/fat is essentially emulsified using ultrasound and/or stabilizers. The process of the invention has enormous application in leather chemicals industry for preparing fatliquor with greater economy of time and energy. Further, the process finds application in chemical industry as a simpler option for emulsification. The major advantage of the process is that it is carried out at ambient temperature. Indian Patent application no. is 201711006779.

A collagen based multifunctional group polymer and a process for the preparation thereof
Disclosed herein is a collagen based multifunctional group polymer exhibiting molecular weight in the range of 3000-5000 D, particle size of 310-950 nm. A very wide stability of the polymer in a wide range of pH, temperature and chemicals ensures significant application in chemicals and processing industries. The product finds application in leather processing industry as a chrome exhaust aid in chrome tanning, whereby the exhaustion level of chromium is enhanced significantly to more than 95%.Further, a process for the preparation of the polymer is also provided using collagen hydrolysate, which is obtained from collagenous sources such as chrome shaving dust, hide/skin trimming, leather buffing dust. Indian Patent application no. is 201611037674.

A novel melamine-chrome complex for leather processing and a process for the preparation thereof
The present invention provides a novel melamine-chrome complex comprising imine groups. It is essentially a formaldehyde free chromium complex consisting of a dialdehyde capable of performing rechroming and retanning in a single step. A process for preparing the said eco-benign complex is also provided. The complex is available in both solid as well as liquid form. It finds enormous application for the purpose of tanning, rechroming and retanning in leather processing. When applied in leather processing, it confers thermal stability to hides/skins. It also helps in filling the empty regions within the fibre matrix, thereby providing fuller leather. Indian Patent application no. is 937DEL2014.

A Novel Composition For Water Free, Pickle Free Chrome Tanning Without Medium And A Chrome Tanning Process Thereof
Disclosed herein is a novel composition of Basic chrome sulphate and metallic salt for chrome tanning of hides and/or skins without adding any water. The chrome tanning process ensures avoiding use of water and the conventional pickling operation. It is envisaged to have tremendous application potential in the tanning industry to ensure eco-benign leather processing that does not add to environmental pollution. The invention is therefore envisaged to play a crucial role in enhancing the economic and environmental benefits associated with chrome tanning. Indian Patent application no. 85Del2014.

A process for the preparation of a tanning cum dyeing agent
A process for the preparation of a tanning cum dyeing agent is disclosed whereby the hydrolysable tannin, leached out from a plant material is reacted with iron salt to get a solution capable of being used as tanning cum dyeing agent in leather processing. The product may optionally be dried conventionally to get the product in powder form.
The invention has been applied for Patent protection (Indian Patent application no. 324DEL2004;Patent pending).

An improved process for the preparation of a tanning agent
The invention relates to a Chromium-Silica compound, prepared by reacting a monovalent cation of hexavalent chromium with a silica salt followed by complexation with organic ligands. The product finds potential application in leather processing industry predominantly as a self tanning agent. It produces leathers with shrinkage temperature of more than 105oC. The resulting leathers exhibit excellent softness, suppleness, stretch, fluffy grain with smooth surface as well as good strength.
The invention has been applied for Patent protection (Indian Patent application no. 770DEL2000; Patent pending).

A process for the preparation of a novel synthetic tanning agent
The process provides a formaldehyde free organo-chrome complex, which is prepared using aromatic polymeric matrix and trivalent chromium salts along with suitable masking agents. The complex can be used as a self-tanning agent for delimed pelts, whereby the conventional pickling process can be completely eliminated. Moreover, the exhaustion of chromium in tanning is enhanced. The product may also be used for retanning to impart excellent fullness to final leather. The tanned leathers exhibit shrinkage temperature of more than 110oC. Owing to the fact that the use of formaldehyde is avoided in the process, this product offers one of the suitable options for eco-friendly tannage of leather.
The invention has been applied for Patent protection (Indian Patent application no. 906DEL2000; Patent pending). The technology has already been commercialized.

<--------------------------------------------End Minaral syntan----------------------------------->

A dispersing agent composition for tanning of hides/skins and a process for the preparation thereof
Disclosed herein is a dispersing agent composition essentially comprising polyalkalene polyhydric compound, carbonyl and/or hydroxyl functionality compound and surfactant. The composition finds application in leather processing industry for tanning without adding any water or any other medium. It finds tremendous application potential in the tanning industry to ensure eco-benign leather processing that does not add to environmental pollution as no effluent is generated. The invention is therefore envisaged to play a crucial role in enhancing the economic and environmental benefits associated with tanning industry. The disclosure also relates to a process for preparing the composition and also the process of eco-benign tanning using the said composition. Indian Patent application no. is 2104DEL2015.

A novel composition for deliming of hides and skins and a process for the preparation thereof
Disclosed herein is a novel deliming composition comprising essentially Phenolic carboxyl acid; Glucose, sodium salt of sulfa compound and antifungal agent. It is prepared from natural plant material of defined part1cle size. The composition finds application in ammonia free process of deliming in leather making. The unique feature of the invention is that it provides a composition comprising essentially phenolic carboxyl acid that ensures neutralization of lime during leather processing operation. Thus, it is envisaged to have enormous application in tanning Industry for hazard free deliming process. Indian Patent application no. is 1367DEL2014.

A synergistic composition for short term preservation of raw hides/skins and a process for the preparation thereof
Disclosed herein is a synergistic composition comprising of esters of Gallic acid and low amount of common salt for application in low salt short term preservation of raw hides/skins in leather making. It is envisaged to have enormous application in tanning industry for minimizing the total dissolved solids (TDS) and salinity significantly in the wastewater streams. Thus it provides a better and eco-benign alternative for the conventional salt based preservation system. The disclosure further provides a process for the preparation of the said synergistic composition. Indian Patent application no. is 1842DEL2014.

A novel composition for preservation of raw hide/skin and preservation process thereof
Disclosed herein is a novel composition comprising common salt and calcium compound for preservation of hide/skin. A process for preservation of hides and skins using the said composition is also provided. The process is envisaged to have tremendous application potential in the leather industry for substantial reduction of TDS and chlorides in the waste streams. The process is expected to enhance the economic and environmental benefits to leather processing industry. Indian Patent application no. is 201611009448.

<--------------------------------------------End of Pretanning auxiliaries----------------------------------->

A Novel Composition Useful For Removal Of Restricted Substances From Leather And A Process For The Preparation Thereof
Disclosed herein is a novel composition comprising essentially sulfate ester, amine and sugar for treating post tanned wet processed leather, whereby the conventional hazardous substances, which have been considered to be restricted to be present in leather, are eliminated. A process for preparing the said composition is also disclosed. The invention is envisaged to have wide application in leather processing industry for making non-hazardous, eco-friendly and safe leather. Indian Patent application no. 786Del2014.

<----------------------------------------End of Chemicals for hazardous substance free leather--------------------------------> A process for the preparation of plant based acrylate composite
The process provides a method of preparation of a composite, whereby alkyl acrylate is polymerized with selected leached plant material. The product has enormous potential application as tanning agent in leather processing industry, thereby suggesting an economical option for utilizing plant materials for eco-benign industrial purpose. The leather produced by using the composite exhibits softness, grain tightness and hydrothermal stability.
The invention has been applied for Patent protection (Indian Patent application no. 1057DEL2001;Patent pending)
An improved process for the preparation of a tanning agent.
A process for the preparation of a tanning agent is provided whereby gallic acid, which is conventionally not a tanning agent, is treated with organic crosslinker to obtain tanning agent for application in leather process industry.
The invention has been applied for Patent protection (Indian Patent application no. 319DEL2004).
An improved process for the preparation of jatropha oil--acrylic co-polymer for tanning applications
The invention relates to in-situ polymerization of acrylic monomer and grafting the resulting polymer onto the jatropha oil backbone without losing the tanning activity of the oil. The resulting polymer finds application as tanning agent in leather processing industry. The product may also be used as a lubricating agent for leather. It has also potential application in textile and surface coating industries. The unique feature of the process is that the resulting product is aqueous based and hence eco friendly. Moreover, jatropha oil, the main constituent, is a naturally renewable resource.
The invention has been applied for patent protection (Indian patent application no. 663Del2006; patent pending)

<!--------------------------------------------Vegetable / Non - Protein Based Syntan----------------------------------->
A chromium - keratin complex and a process for the preparation thereof

The invention provides a keratin-silica matrix by hydrolyzing keratin polypeptides with known silica salt, thereby ensuring not only the antimicrobial property of the product, but also to obtain the product in pH range of 7.5 – 9.0 without neutralization with acid. The product exhibits a molecular weight in the range of 2 KDa and 6 KDa, particle size 2000 and 5000 nm and pH 7.5 – 9.0. The product finds enormous potential as an important bio-alternative to replace the conventional fillers and binders for leather finishing. It may also be used as retanning agent in leather processing that will influence the uptake of subsequently applied auxiliaries such as dyestuffs and fatliquors. Besides, this matrix may also be used for pickle free tannage. This may also be used as chromium free tanning agent and as exhaustive aid in conventional chrome tanning process. The invention has been applied for Patent protection (Indian Patent application no. 1241DEL2008).
A bioactive keratin-silica matrix and a process for the preparation thereof
The invention provides a keratin-silica matrix by hydrolyzing keratin polypeptides with known silica salt, thereby ensuring not only the antimicrobial property of the product, but also to obtain the product in pH range of 7.5 – 9.0 without neutralization with acid. The product exhibits a molecular weight in the range of 2 KDa and 6 KDa, particle size 2000 and 5000 nm and pH 7.5 – 9.0. The product finds enormous potential as an important bio-alternative to replace the conventional fillers and binders for leather finishing. It may also be used as retanning agent in leather processing that will influence the uptake of subsequently applied auxiliaries such as dyestuffs and fatliquors. Besides, this matrix may also be used for pickle free tannage. This may also be used as chromium free tanning agent and as exhaustive aid in conventional chrome tanning process. The invention has been applied for Patent protection (Indian Patent application no. 1241DEL2008).
A process for the preparation of a novel proteinoid-acrylate composite having molecular weight in the range of 15000-20000 KD.
The process essentially provides a proteinoid acrylate composite for application as filler cum syntan in leather processing industry. The preparation process of the product involves copolymerisation of protein hydrolysate with acrylic resin to obtain a composite of molecular weight in the range of 15000-20000 KD. The product finds potential application in post tanning wet operations to get excellent filling effect, grain tightness as well as softness in the finished leather. It also ensures exhaustion of dye bath to the tune of 98%. Moreover, the leather processed by this product becomes more amenable to buffing not only for producing corrected grain leather, but also for getting good nap while making suede leathers. Since the composite can withstand a temperature as high as 200oC, it can safely be used for processing even glazed finished leathers. The composite may also be effectively used as a filler in cardboard industry. Thus the invention provides an economical as well as eco-friendly option of utilizing proteinous wastes of any industry for preparing value added products.
The process has been applied for Patent protection (Indian Patent application no. 210DEL2001; Patent pending).
A process for the preparation of a novel proteinoid for industrial applications
The process provides a method of oxidation of protein hydrolysate with organo oxidising agent which would result as aldehyde, a tanning material, having enormous potential as tannin in leather processing, thereby suggesting not only an economical option for utilizing the proteinous wastes of different industries including leather industry in useful way, but also an eco-friendly measure for leather processing using the resulting product of the present invention. The proteinoid of this invention finds potential application in leather processing industry as a tanning agentto get softness,fullness,buffing property and lightweightness to the resulting leather. It may also be used in photographic and carpentry industry.
The invention has been applied for Patent protection (Indian Patent application no. 172DEL2002).
A tanning composition and a process for the preparation thereof
A tanning composition for application in leather processing industry has been disclosed. The invention further provides a process for the preparation of the composition. Generally, the tanned leathers are retanned with a combination of synthetic tanning agents to enhance the properties such as fullness, grain tightness, grain smoothness and roundness. Many of the chemicals that go into the preparation of such synthetic tanning agents are toxic and slow biodegradable. Further, in industrial practice, several synthetic tanning agents are combined to obtain a desired property. In the present invention, a synthetic tanning agent using natural and proteinous waste materials is disclosed, which provides to the leather the properties such as better fibre lubrication, filling of looser ends, softness, shape retention and fabrication comforts without combining with other synthetic tanning agents.
The invention has been applied for Patent protection (Indian Patent application no. 0648DEL2007).
Novel acrylic grafted keratin hydrolysate copolymer for industrial applications and a process for the preparation thereof
Disclosed herein is a new acrylic grafted keratin hydrolysate copolymer synthesized by free radical polymerization technique. It finds potential application in leather processing industry as retanning agent and also as a filler. The exhaustion of the product in wet processing of leather is excellent. Further, it may also be used as additive in the preparation of concrete, ceramic and cosmetic industry. The product exhibits very good film formation and mechanical strength. The invention provides a promising option to utilize Keratin hydrolysate, a biowaste, for useful industrial purpose. Indian Patent application no. is 201611038898.
A novel retanning agent and a process for the preparation thereof
Disclosed herein is a novel retanning agent exhibiting particle size in the range of 162-342 nm and stability in the pH range of 5.5-13.0. A collagen-keratin source is hydrolysed and the resulting protein hydrolysate is treated with glycerol, and saccharides under stipulated conditions to obtain the retanning agent. The invention provides an option to utilize tannery raw trimmings for making retanning agent for leather making. The product enhances the uniformity of dyeing and increases the color intensity even with low quantity of dye. The developed product may serve as a good auxiliary to enhance the filling and dyeing in leather processing. Indian Patent application no. is 2509DEL2014.
An improved tanning composition and a tanning process thereof
Disclosed herein is a novel retanning agent exhibiting particle size in the range of 162-342 nm and stability in the pH range of 5.5-13.0. A collagen-keratin source is hydrolysed and the resulting protein hydrolysate is treated with glycerol, and saccharides under stipulated conditions to obtain the retanning agent. The invention provides an option to utilize tannery raw trimmings for making retanning agent for leather making. The product enhances the uniformity of dyeing and increases the color intensity even with low quantity of dye. The developed product may serve as a good auxiliary to enhance the filling and dyeing in leather processing. Indian Patent application no. is 2509DEL2014.
<!--------------------------------------------Protein Based Syntan----------------------------------->
A novel retanning agent and a process for the preparation thereof
The invention provides water soluble confined organic colourants for colouring application with monodispersed particles. These confined colourants, which exhibit stability in the pH range of 2.5-9, uniformly colour the substrate without any influence of the substrate environment especially in leather colouring. The present invention essentially provides an opportunity to colour leather at any stage of wet processing, rather than the conventional system of leather colouring after tanning and neutralization of the hide/skin. Confinement of colourants inside the novel polymeric matrix ensures this. These colourants are used in colouring application devoid of any influence of the charge and pH of the substrate, leading to uniform colouring and improved fastness and perspiration resistance. Hence the metal organic matrix penetrates and fix into the substrate without any need of fixing agent and colouring auxiliaries. Indian Patent application no. is 2727DEL2014.
<!--------------------------------------------Dyeing auxiliaries----------------------------------->
A novel cyclohexyl carbo-dihydropyrimidine thione compound and a process for the preparation thereof
Disclosed herein is a novel cyclohexyl carbo-dihydropyrimidine thione compound and a process for its preparation involving use of aromatic aldehydes, diketone and urea under solvent and catalyst free conditions. The reaction time is as short as 30 minutes. The yield is as high as 80% with no generation of toxic byproduct. The invention essentially provides an eco­benign alternative to the conventional fungicides which are associated with environmental health hazards. It finds enormous application in leather processing industry, especially during the wet blue Stage as well as in retanning stage, to avoid fungal deterioration. It also finds potential application in pharmaceutical industry. Indian Patent application no. is 1631DEL2014.
<!--------------------------------------------Antifungal composition----------------------------------->
An improved process for the preparation of a novel graft copolymer having molecular weight upto 300 000
The process relates to the use of serum, which is discarded as waste adding to environmental pollution, for preparing protein-acrylate graft copolymer, having such properties as are necessary for being used as film forming thermostable binder in leather finishing formulations for resin or glaze finish. The binder results in good lusture without masking the grain pattern. The polymer has also application as coating agent in paint industry. The invention provides a simple option not only for effective utilization of a waste, but also for preparing a good auxiliary for industrial applications.
The process has been applied for Patent protection (Indian Patent application no. 787DEL2000; Patent pending).
An improved process for the preparation of wax emulsion.
Inert wax is emulsified using long chain alcohols for preparation of auxiliaries used in leather finishing. These wax emulsions are superior to other conventional wax emulsions in terms of properties.
The invention has been applied for Patent protection (Indian Patent application no. 199DEL2004;Patent pending).
An inorganic yellow pigment for industrial applications and a process for the preparation thereof
Disclosed herein is an inorganic yellow pigment exhibiting Near Infra-Red (NIR) reflectance of 80-95% and solar reflectance of 89-98%. It is essentially a rare earth metal ion based oxide pigment which has the potential to reflect the solar radiation near infrared wavelength region leading to potential application as a cool yellow pigment for various surface coating applications. The pigment is envisaged to have enormous application in coloring of plastics, leather, ceramic and exterior surfaces of buildings. It ensures an enhancement of NIR reflectance by around 95% compared to that of the conventional inorganic yellow pigment. The pigment also finds application in thermally comfortable interiors. It is expected to reduce the energy costs required for cooling of automobile interiors, buildings etc. by way of reflecting heat inducing solar radiations. Indian Patent application no. is 1980DEL2015.
<!--------------------------------------------Finishing Auxiliaries----------------------------------->
A Novel Adhesive and a microbial process For the preparation thereof.
Marine bacterial Bacillus sp. deposited in IMTECH, Chandigarh is grown in the mineral rich medium containing vegetable oil. The medium is then incubated under controlled conditions and the resulting adhesive is separated by conventional method. The adhesive product is characterized as thick clumpy mass appearance, having Viscosity of about: 20.0 - 38.01 x 10–3 cps, thermal stability up to 280 - 320C, tensile-strength of about 6.2 –7.5 N/mm2. It exhibits good adhesion against cellulose, glass and cotton. The adhesive finds enormous application in product industries for the fabrication of consumer goods.
The invention has been applied for patent protection (Indian Patent application no. 2067DEL2010).
A process for the preparation of poly(acyl sulfide) for industrial applications.
A process for the preparation of poly(acyl sulfide) is disclosed whereby acid dichloride is condensed with alkali metal sulfide in presence of phase transfer catalyst, thereby forming the polymer in one step reaction. The polymer of the invention finds enormous potential application as adhesive in footwear and leather goods industry. It may also be used as fuel binder in rocket propellant.
The invention has been applied for Patent protection (Indian Patent application no. 0751DEL2002; Patent pending).
A process for the preparation of novel polysulfide copolymers.
A process for the preparation of novel polysulphide copolymers is provided whereby styrene dibromide is polymerized with ethelene/methylene dibromide in presence of sodium/potassium sulfide using phase transfer catalyst. The polysulfide co-polymers prepared by this new process exhibit melting point in the range of 59-125oC and are soluble in organic solvents thereby ensuring their easy processability for industrial applications. These polymers find potential applications in footwear, leather goods and allied industries as adhesive. These may also find potential application in the works pertaining to construction and maintenance of concrete structures such as highways, airport runways. Moreover, they are envisaged to have several applications as sealant in aircraft industry. The polymer may also be used as insulator in electrical industry.
The invention has been applied for Patent protection (Indian Patent application no. 1010DEL2001;Patent pending)
An eco- friendly Adhesive composition and a process for the preparation thereof.
This invention relates to an eco-friendly adhesive composition for leather, paper, textiles, cellulose etc., comprising a hydroxyl terminated polyvinyl alcohol and ferric chloride. It finds application as strong adhesive in products industries comprising leathers, paper, textiles, and cellulose. Indian Patent application no. is 2077DEL2014.
<!--------------------------------------------End of Adhesive----------------------------------->
For Further Information Please Contact

Head, Business Processes Division,
CLRI, Adyar, Chennai 600 020.
Tel.:+91 44 2491 5238
email : e-mail :bpdclri@yahoo.com;
bpd@clri.res.in