Title of Invention

A PROCESS FOR PPREPARING OF A PERCHEMENT LIKE MATERIAL

Abstract

A process for the preparation of a parchment like material by size reduction of chrome shavings to a fibre size of not more than 35 mm by known method, followed by hydrolysis with alkali by conventional method at a pH in the range of 10-13 for a period in the range of 0.5-4 hrs to get a semi solid mass, adjusting the pH of the semi solid mass, as formed in step (i), in the range of 1.5-3 by conventional method, optionally raising the pH of the resulting mass to a range of 3.5-5 by known method, adding 1-5% w/v of conventional plasticizer and/ or 0.05-0.2% w/v of conventional crosslinker to the mass followed by casting and subsequent drying by conventional method at a temperature in the range of 35-50°C to get parchment like material.

Full Text

The present invention relates to a process for the preparation of a parchment like material. More particularly, the present invention relates to a process for the preparation of parchment like material using chrome shavings as the raw material. The material prepared by the process of this invention is envisaged to have enormous potential application in puppet industry. It may also be used for cottage/small scale industries relating to fancy items including lamp shades. Moreover, the material can also be used for effecting reinforcement in leather goods industry. The history of parchment is hidden in the mists of antiquity. A parchment is essentially a piece of untanned hide or skin, preserved usually by drying. It has been used by the mankind from time immemorial. As reported by Garness ( Robert E. Krieger publication, Florida, USA, page-20, 1986), fresh hides and skins are pegged to the ground keeping grain side up and are dried under the sun after strewing ash on the grain side of the pieces. The hair is scrapped off at the semi dried condition and the resulting pelt is known as parchment, which has use in drums and other musical instruments. The major limitation associated with this process is that the hides/skins, which are used in the green condition, contain flesh and other extraneous matters, that are prone to quick putrefaction. Moreover, the sundrying, involved in this process, may also result in case hardening, thereby resulting in the interior putrefaction of the proteinous matters. Attempts were made to improvise upon this method by Selvarangan et al ( Leather Science, 11,99,1964), who soaked buff calf skins in water for few days with regular 'working on' till the hair and flesh got loosened by bacterial action and subsequently removed by knife. The major limitation associated with this process is that the bacterial action, initiated in the soak bath, is likely to degrade the quality of the stock. Selvarangan et al ( Indian Leather, 19,17,1986) made parchment from goat skins, whereby the fresh skins were left in lime liquor for a few days and then unhaired, fleshed before shaping to uniform thickness followed by drying to get transparent parchment. Attempts have also been made by Selvarangan et al ( Leather Science, 11,99,1964) to make parchment from thicker hides, whereby the raw materials are subjected to green splitting followed by conventional liming and subsequent drying. Although this variety is much better in respect of transparency, yet it is still associated with the limitation of likelihood of putrefaction and insect damage, since the collagenous protein of the hide/skin is subjected only to curing or temporary preservation and not any process of permanent preservation. Another limitation associated with this parchment is that it is likely to putrefy as soon as it comes in contact with water. Yet another limitation associated with the hitherto available parchment is that the thermal stability of these materials do not go beyond 50-60°C, since they are not tanned substances. The above limitations of the existing parchment have prompted the researchers to develop a better option for making parchment. This problem of the possibility of quick decay of the parchment, made from untanned hide or skin can be overcome by using tanned substances like chrome shavings, trimmings. Chrome shavings are the prominent solid wastes in the tanning industry. Since chromium is known for its toxicity, the disposal of the chrome shavings, generated as solid wastes in the tanning industry, has been identified as a serious problem from the view point of environmental safety. As reported by Taylor et al ( Journal of American Leather Chemists Association, 85, 264, 1990), sanitary land fills are reluctant to accept chromium- containing wastes because of the possibility of Cr(lll) waste being oxidized to the toxic Cr(VI) and contaminating the ground water. There is, therefore, an urgent need to find an economical method of disposal of this solid waste. Several attempts are being made by the researchers to use the chrome shavings for useful purpose so as to solve the waste disposal problem by suggesting a method to prepare value added product. No prior art is however available on the process of using chrome shavings for making parchment like material which can be used for several fancy items. The main object of the present invention is to provide a process for the preparation of a parchment like material, which obviates the drawbacks stated above. Another objective of the present invention is to use the chrome shavings as a raw material source for the preparation of the parchment like material. Yet another objective of the invention is to provide a process for the preparation of a parchment like material having stability upto a temperature of 70°C. Still another objective of the invention is to provide a process for the preparation of a parchment like material which is not prone to either insect damage or putrefaction. Yet another objective of the invention is to provide a process for the preparation of a parchment like material which is not likely to putrefy as soon as it comes in contact with water. Accordingly, the present invention provides a process for the preparation of a parchment like material which comprises, i. size reduction of chrome shavings to a fibre size of not more than 35 mm by known method, followed by hydrolysis with alkali by conventional method at a pH in the range of 10-13 for a period in the range of 0.5-4 hrs to get a semi solid mass, ii. adjusting the pH of the semi solid mass, as formed in step (i), in the range of 1.5-3 by conventional method, iii. optionally raising the pH of the resulting mass to a range of 3.5-5 by known method, iv. adding 1-5% w/v of conventional plasticizer such as herein described and/ or 0.05-0.2% w/v of conventional crosslinker such as herein described to the mass, as formed in step(ii) or step(iii), followed by casting and subsequent drying by conventional method at a temperature in the range of 35-50°C to get parchment like material. In an embodiment of the present invention, the machinery used for the size reduction of chrome shavings may be such as ball mill, hammer mill, homogeniser. In another embodiment the present invention, the conventional alkali used for alkali hydrolysis may be such as calcium hydroxide, sodium hydroxide, potassium hydroxide. tn yet another embodiment of present invention, the conventional plasticiser used may be such as glycerine, sorbitol, poly ethylene glycol. In still another embodiment of present invention, the conventional crosslinker used may be such as formaldehyde, glutaraldehyde, Basic chromium sulphate. In yet another embodiment of present invention, the conventional method of drying used may be such as air drying, sun drying, vacuum drying. The parchment material of the present invention is prepared in the following way: Fibre size of chrome shavings is reduced to a maximum of 35 mm by known method and the resulting material is subjected to alkali hydrolysis by conventional method at a pH in the range of 10-13 for a period in the range of 0.5-4 hrs to get a semi solid mass. pH of the resulting mass is gradually brought down by known method in the range of 1.5-3.0. Then the pH of the resulting semi solid mass is optionally raised to a point in the range of 3.5-5.0. 1-5% w/v of conventional plasticiser and/ or 0.05-0.2% w/v of conventional crosslinker are then added to the resulting mass, which is cast into desired shape/size and subjected to drying by conventional method at a temperature in the range of 35-50o C to get parchment like material. The novelty and non-obviousness of the present invention lies not only in identifying chrome shavings as a new source for making parchment, but also in providing a process for forming a thin and transparent sheet with the shavings after partial dechroming, whereby the resulting chrome liquor can be reused for the purpose of leather tannage, thereby suggesting a method for utilising the chrome shavings, which would otherwise create the problem of solid waste disposal, for making value added product. The following examples are given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention. Example-1 1 kg. of chrome shavings were taken and powdered in a hammer mill to 10 mm size. The powdered chrome shavings were then taken in a beaker and 8 lit of water were added to it. The powdered chrome shavings were washed in water by stirring the mass continuously. After a period of 1 hr, the shavings were squeezed using nylon mesh and the resulting mass was taken in a plastic bucket. pH of the said mass was noted to be 6.2. 1.5 lit. of 3N NaOH solution was then added to the above mass with continuous stirring. After a period of 30 min., pH of the resulting semi solid mass was noted to be 10. 400 ml. of 0.25 N sulfuric acid was then added slowly to the bucket containing the semi solid mass with continuous stirring. After a period of 20 min, pH of the mass was noted to be 1.5. The above mass was filtered through nylon mesh and 1 lit of the precipitate was collected in a beaker. 10 ml. of glycerol was then added the the beaker while stirring the contents continuously for a period of 30 min. The resulting homogeneous mass was then cast into a sheet of rectangular shape having 30cmx15cm dimension, followed by air drying at 45°C. The resulting transparent sheet of parchment like material was found to withstand a temperature of 70°C without any sign of deterioration and was stored. The final transparent parchment like material was used for making lamp shade and greetings card. Example-2 1 kg. of chrome shavings were taken and powdered in a pulverizer to 20 mm size. The powdered chrome shavings were then taken in a beaker and 8 lit of water were added to it. The powdered chrome shavings were washed in water by stirring the mass continuously. After a period of 1 hr, the shavings were squeezed using nylon mesh and the resulting mass was taken in a plastic bucket. pH of the said mass was noted to be 6.5. 1.8 lit. of 3N KOH solution was then added to the above mass with continuous stirring. After a period of 4hrs, pH of the resulting semi solid mass was noted to be 13. 450 ml. of 0.25 N hydrochloric acid was then added slowly to the bucket containing the semi solid mass with continuous stirring. After a period of 40 min, pH of the mass was noted to be 3. The above mass was filtered through nylon mesh and 1 lit of the precipitate was collected in a beaker.. A mixture of 50 ml. of ethylene glycol and 2 ml of glutaraldehyde was then added to the beaker while stirring the contents continuously for a period of 40 min. The resulting homogeneous mass was then cast into a sheet of rectangular shape having 30cmx15cm dimension, followed by sun drying. The resulting transparent sheet of parchment like material was found to withstand a temperature of 70°C without any sign of deterioration and was stored. The final transparent parchment like material was used for making puppets. Example-3 1 kg. of chrome shavings were taken and powdered in a ball mill to 20 mm size. The powdered chrome shavings were then taken in a beaker and 8 lit of water were added to it. The powdered chrome shavings were washed in water by stirring the mass continuously. After a period of 1 hr, the shavings were squeezed using nylon mesh and the resulting mass was taken in a plastic bucket. pH of the said mass was noted to be 6.7. 2 lit. of 0.1N calcium hydroxide solution was then added to the above mass with continuous stirring. After a period of 3.5 hrs, pH of the resulting semi solid mass was noted to be 11.5. 400 ml. of 0.25 N hydrochloric acid was then added slowly to the bucket containing the semi solid mass with continuous stirring. After a period of 40 min, pH of the mass was noted to be 2.5. it was then washed in plain water and the final pH was noted to be 3.5. The above mass was filtered through nylon mesh and 1 lit of the precipitate was collected in a beaker. A mixture of 20 ml. of sorbitol and 500 mg of basic chromium sulphate was then added to the beaker while stirring the contents continuously for a period of 45 min. The resulting homogeneous mass was then cast into a sheet of rectangular shape having 30cmx15cm dimension, followed by sun drying. The resulting transparent sheet of parchment like material was found to withstand a temperature of 70°C without any sign of deterioration and was stored. The final transparent parchment like material was used for making puppets. Example-4 1 kg. of chrome shavings were taken and powdered in a ball mill to 25 mm size. The powdered chrome shavings were then taken in a beaker and 8 lit of water were added to it. The powdered chrome shavings were washed in water by stirring the mass continuously. After a period of 1 hr, the shavings were squeezed using nylon mesh and the resulting mass was taken in a plastic bucket. pH of the said mass was noted to be 6.7. 2 lit. of 0.1 N calcium hydroxide solution was added to it with continuous stirring. After a period of 3.5 hrs, pH of the resulting semi solid mass was noted to be 11.5. 400 ml. of 0.25 N sulphuric acid was then added slowly to the bucket containing the semi solid mass with continuous stirring. After a period of 40 min, pH of the mass was noted to be 2.5. it was then washed in plain water and the final pH was noted to be 4.5. The above mass was filtered through nylon mesh and 1 lit of the above precipitate was collected in a beaker. A mixture of 20 ml. of polyethylene glycol and 1 ml of formaldehyde was then added to the beaker while stirring the contents continuously for a period of 45 min. The resulting homogeneous mass was then cast into a sheet of rectangular shape having 30cmx15cm dimension, followed by vacuum drying. The resulting transparent sheet of parchment like material was found to withstand a temperature of 70°C without any sign of deterioration and was stored. The final transparent parchment like material was used for making puppets. Example-5 1 kg. of chrome shavings were taken and powdered in a ball mill to 35 mm size. The powdered chrome shavings were then taken in a beaker and 8 lit of water were added to it. The powdered chrome shavings were washed in water by stirring the mass continuously. After a period of 1 hr, the shavings were squeezed using nylon mesh and the resulting mass was taken in a plastic bucket. pH of the said mass was noted to be 6.7. 2 lit. of 3N sodium hydroxide solution was added to it with continuous stirring. After a period of 3.5 hrs, pH of the resulting semi solid mass was noted to be 12.5. 400 ml. of 0.25 N sulphuric acid was then added slowly to the bucket containing the semi solid mass with continuous stirring. After a period of 40 min, pH of the mass was noted to be 2.5. it was then washed repeatedly in plain water and the final pH was noted to be 5. The above mass was filtered through nylon mesh and 1 lit of the above precipitate was collected in a beaker. A mixture of 20 ml. of polyethylene glycol and 1 ml of formaldehyde was then added to the beaker while stirring the contents continuously for a period of 45 min. The resulting homogeneous mass was then cast into a sheet of rectangular shape having 30cmx15cm dimension, followed by vacuum drying. The resulting transparent sheet of parchment like material was found to withstand a temperature of 70°C without any sign of deterioration and was stored. The final transparent parchment like material was used for making puppets. The advantages of the present invention are the following. 1. The process suggests a very simple and economically viable method for utilising chrome shavings, one of the prominent solid wastes emanating from a tannery. 2. The process does not require much investment. 3. The parchment like material, prepared by the process of the present invention exhibits good transparency and flexibility, thereby making it suitable for use in pupppets, leather goods and footwear industries. 4. The product exhibits thermal stability upto 70°C. 5. The material is not prone to either insect damage or putrefaction. 6. The parchment like material, prepared by the process of the present invention is not likely to putrefy as soon as it comes in contact with water. 7. The acidified chromium solution obtained in this process can be reused in the leather processing, thereby suggesting a method for recovery and reuse of chromium. WE CLAIM : 1. A process for the preparation of a parchment like material which comprises, v. size reduction of chrome shavings to a fibre size of not more than 35 mm by known method, followed by hydrolysis with alkali by conventional method at a pH in the range of 10-13 for a period in the range of 0.5-4 hrs to get a semi solid mass, vi. adjusting the pH of the semi solid mass, as formed in step (i), in the range of 1.5-3 by conventional method, vii. optionally raising the pH of the resulting mass to a range of 3.5-5 by known method, viii. adding 1-5% w/v of conventional plasticizer such as herein described and/ or 0.05-0.2% w/v of conventional crosslinker such as herein described to the mass, as formed in step(ii) or step(iii), followed by casting and subsequent drying by conventional method at a temperature in the range of 35-50°C to get parchment like material. 2. A process, as claimed in Claim 1, wherein the machinery used for the size reduction of chrome shavings is ball mill, hammer mill, homogeniser. 3. A process, as claimed in Claims 1 and 2, wherein the conventional alkali used for alkali hydrolysis is calcium hydroxide, sodium hydroxide, potassium hydroxide. 4. A process, as claimed in Claims 1 to 3, wherein the conventional plasticizer used is glycerine, sorbitol, poly ethylene glycol. 5. A process, as claimed in Claims 1 to 4, wherein the conventional crosslinker used is formaldehyde, glutaraldehyde, basic chromium sulphate. 6. A process, as claimed in Claims 1 to 5, wherein the conventional method of drying used is air drying, sun drying, vacuum drying. 7. A process for the preparation of a parchment like material, substantially as herein described with reference to the examples.

Documents:

300-del-2001-abstract.pdf

300-del-2001-claims.pdf

300-del-2001-correspondence-others.pdf

300-del-2001-correspondence-po.pdf

300-del-2001-description (complete).pdf

300-del-2001-form-1.pdf

300-del-2001-form-18.pdf

300-del-2001-form-2.pdf