Title of Invention | A PROCESS FOR TREATING PLASTICIZED POLYINYL CHLORIDE |
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Abstract | 1. A process for treating plasticized polyvinyl chloride (F*PVC)? for retarding the migration of the plasticizer comprising in the steps of treating the PPVC sheets in aqueous medium containing a cross-linking agent and a catalyst such as herein described) by keeping the sheet immersed in the solution. |
Full Text | This invention relates to a process for treating plasticized /polyvinyl chloride for retarding the migration of the plasticizer / without affecting any of the bulk properties of the polymer sheet. Plasticized polyvinyl chloride (PPVC) is widely used for various applications and comprises a physical mixture of additives like plasticizer, various types of stabilizers, lubricants, etc.. Diethyl hexyl pthalate (DEHP), is being commonly used as plasticizer for polyvinyl chloride and it may contain 30 or more percentage of the same by weight. Because of heterogeous composition or by aging, DEHP may exude so that it may cause toxic effects. Several attempts have been reported by various researchers to minimise the leaching by grafting various polyme-rizable monomers of hydrophobic to hydrophilic in nature, by different techniques. However, it has been observed that other basic requirements like mechanical property, transparency, etc. significantly reduced on these modifications. An object of this invention is to propose a process for treating plasticized polyvinyl chloride for retarding the migration of the plasticizer and without affecting any of the bulk properties. Another object of this invention is to propose a process for treating plasticized polyvinyl chloride for retarding the migration of the plasticizer and without affecting the transpa¬rency. urther objects and advantages of this invention will be more pparent from the ensuing description. : the outset of the description which follows, it is to be iderstood that the ensuing description only illustrates-a parti- lar form of this invention. However, such a particular form only an exemplary embodiment, and without intending to imply i limitation on the scope of this invention. Accordingly, ; description is to be understood as an exemplary embodiment teaching of the invention and not intended to be taken trictively. According to this invention there is provided a process for treating plasticized polyvinyl chloride (PPVC), for retarding the migration of the plasticizer, comprising in the steps of treating the PPVC sheets in aqueous medium containing a cross-linking agent and a catalyst such as herein described, by keeping the sheet immersed in the solution. Such a treatment is carried out at a temperature of 80 to 90 C. The treatment is carried out using aluminium chloride and TDMAC, wherein 150 ml distilled water contains 0lg to 2.0g aluminium chloride and 0.1g to 1.0g TDMAC. PPVC sheet of thickness 3mm approximately 100 sqcm surface is treated in 150 ml of distilled water containing 1.0g of aluminium chloride and 0.5g of TDMAG at above mentioned condition and duration. 60'/« reduction by weight in plasticiser leaching in n™ hexane was observed compared to the untreated one for upto 18 h rs .v . In accordance with another embodiment, the sheet is treated with hewamethylene diamine, a crosslinking agent and catalyst. Polymer shoets of surface area approximately 100 sq.cm. is treated with 150 ml of distilled water containing 1«0Q of hexamethylene Q diamine anc| 0.5g of TDMAC, at 80-90 C for 2 hrs.. Even though treated, one showed negligible leaching into n-hexan-e, the polymer sheet has been found to be degraded turning colour into reddish yellow. The crosslinking agent can be epoxypropyl methacrylate - The same treatments was attempted with 0.,25g of hexamethylene diamine and 1.0 ml of 2.3 epoxypropyl. methacrylat e, a crosslinking agent at 60-70 C far 2 hrs. In this case, a 50% reduction in plasticizer migration in n--hexane far a duration of 18 hrs. was observed. The catalyst can far eg. be benzyl dimethyl hexadecyl ammonium chloride, tetramethyl ammonium chloride tetramethyl ammonium hydroxide, bennyl triethyl ammonium chloride, etc. . We Claims 1. A process for treating plasticized polyvinyl chloride (F*PVC)? for retarding the migration of the plasticizer comprising in the steps of treating the PPVC sheets in aqueous medium containing a cross-linking agent and a catalyst such as herein described) by keeping the sheet immersed in the solution. 2. The process as claimed in claim 1 wherein said cross-linking agent is selected from tridodecyl methylammonium chloride (TDMAC) or 2,Z5 epokypropyl methacrylate 3. The process as claimed in claim I wherein said catalyst is selected from the group comprising benzyl triethyl ammonium chloride, benzyl dimethyl hexadecyl ammonium chloride, tetra-methyl ammonium chloride, tetramethyl ammonium hydroxide. 4. The process as claimed in claim 1 wherein distilled water is used as the aqueous medium. 5. The process as claimed in claim 1 wherein 150ml distilled water contains 0„lg to 2.0g aluminium chloride and 0.1Q to 1.0g of TDMAC. 6. The process as claimed in claim 1 wherein said PPVC sheets are treated for 30 to 180 mins.„ 7. The process as claimed in claim 1 wherein said PPVC sheets are treated at 80-90 C. 8. A process for treating plasticized polyvinyl chloride (PF'VC) for retarding the migration of the plasticizer substantially as h e r ein described , Hated this 22nd day of NOVfiMBER, 1996„ |
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1075-mas-1995 correspondence-others.pdf
1075-mas-1995 correspondence-po.pdf
1075-mas-1995 description (complete).pdf
Patent Number | 192920 | |||||||||
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Indian Patent Application Number | 1075/MAS/1995 | |||||||||
PG Journal Number | 30/2009 | |||||||||
Publication Date | 24-Jul-2009 | |||||||||
Grant Date | 15-Mar-2005 | |||||||||
Date of Filing | 23-Aug-1995 | |||||||||
Name of Patentee | M/S. SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY | |||||||||
Applicant Address | BIOMEDICAL TECHNOLOGY WINH SATELMOND, PALACE, THIRUVANANTHAPURAM 695 012 | |||||||||
Inventors:
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PCT International Classification Number | C08F114/06 | |||||||||
PCT International Application Number | N/A | |||||||||
PCT International Filing date | ||||||||||
PCT Conventions:
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