Title of Invention

A PROCESS FOR TREATING PLASTICIZED POLYINYL CHLORIDE

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„


Documents:

1075-mas-1995 claims.pdf

1075-mas-1995 correspondence-others.pdf

1075-mas-1995 correspondence-po.pdf

1075-mas-1995 description (complete).pdf

1075-mas-1995 drawings.pdf

1075-mas-1995 form-1.pdf

1075-mas-1995 form-13.pdf

1075-mas-1995 form-26.pdf

1075-mas-1995 form-4.pdf

1075-mas-1995 form-5.pdf

1075-mas-1995 form-9.pdf

1075-mas-1995 petition.pdf


Patent Number 192920
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:
# Inventor's Name Inventor's Address
1 P.R.HARI M/S. SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY BIOMEDICAL TECHNOLOGY WINH SATELMOND, PALACE, THIRUVANANTHAPURAM 695 012
2 CHANDRA P. SHARMAS M/S. SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY BIOMEDICAL TECHNOLOGY WINH SATELMOND, PALACE, THIRUVANANTHAPURAM 695 012
PCT International Classification Number C08F114/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA