Thermal stabilization of IPBC biocide
A biocide, e.g. IPBC (3-iodo-2-propynl butylcarbamate), is stabilized against thermal degradation in matrix compositions which are processed at elevated temperatures, by blending the IPBC with a stabilizer additive, e.g. calcium stearate and/or a hindered phenol, alone or in combination therewith.
1 . A concentrate of a biocide and a stabilizer additive to protect the biocide against thermal degradation when processed in a matrix at temperatures of up to 250° C.
2 . A concentrate according to claim 1 wherein said biocide contains an iodopropynyl group and is selected from iodopropynyl butyl carbamate (IPBC), 3-iodopropynyl carbamate (IPC) and 3-iodopropynyl-N-phenyl carbamate (IPPC) is present in amounts, by wt. of up to 15% and said stabilizer additive is present in an amount of up to 3%.
3 . A concentrate according to claim 2 which includes up to 10% IPBC and up to 1% stabilizer additive.
4 . A concentrate according to claim 1 wherein said additive stabilizer is calcium stearate.
5 . A composition of a plastic matrix, IPBC and a stabilizer additive to protect the IPBC against thermal degradation during processing of the composition into a finished product at elevated temperatures.
6 . A composition according to claim 5 which includes, by wt., 30-95% polyolefin, 5-15% IPBC and 1-3% stabilizer additive, optionally with a colorant, light, UV stabilizer, anti-stat agent or coupling agent.
7 . A composition according to claim 5 which includes about 89% polyolefin, 10% IPBC and 1% stabilizer additive.
8 . A composition according to claim 5 wherein said stabilizer additive is calcium stearate.
9 . A composition according to claim 5 wherein said plastic is linear low density polyethylene or polypropylene.
10 . A composition according to claim 5 wherein said plastic is a composite of polyolefin and wood chips/flour.
11 . A composition according to claim 5 wherein said matrix is flexible polyvinylchloride or a polyurethane.
12 . A method of processing an IPBC-containing composition at high temperatures without degrading the IPBC which comprises including a stabilizer additive in the composition.
13 . A method according to claim 12 wherein said composition includes a matrix which is a polyolefin, flexible polyvinylchloride, a polyurethane or a wood composite.
14 . A method according to claim 13 wherein said stabilizer additive is calcium stearate.
15 . A method according to claim 13 wherein the stabilizer additive also includes an antioxidant.
16 . A method according to claim 15 wherein said antioxidant is a hindered phenol.