Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
1999-08-04
2001-03-20
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S333400, C525S331700, C525S332100, C525S356000, C525S214000
Reexamination Certificate
active
06204334
ABSTRACT:
FIELD OF INVENTION
Post chlorinated polyvinyl chloride (CPVC) and/or polyvinyl chloride (PVC) can use a blocky chlorinated polyolefin to compatibilize them (PVC or CPVC) with a polyolefin rubber. The blend of PVC and/or CPVC with the blocky chlorinated polyethylene and polyolefin rubber (elastomer) can have a combination of good impact resistance, high heat distortion temperature (relative to the base CPVC or PVC), good tensile properties, oxidation resistance, and stability to ultraviolet light (UV) exposure. A process is disclosed for block chlorinating polyolefins (e.g. polyethylene) without appreciably swelling the polyolefin or melting the crystalline phase. The process produces a polymeric product having both high chlorine content blocks (e.g. up to 50-75 wt. % chlorine) and relatively non-chlorinated crystallizable polyolefin blocks. The resulting polymer is characterized as blocky. Said crystallizable polyolefin blocks are generally part of the same polymer that is chlorinated. The two different blocks can compatibilize a CPVC or PVC with a polyolefin rubber.
BACKGROUND OF INVENTION
Polyolefins have been chlorinated in the past. Randomly chlorinated polyethylenes (e.g. Tyrin™ from Dow Chemical) have been used in PVC or CPVC blends, generally as a processing aid and impact modifier. The chlorinated polyethylenes used in PVC or CPVC blends have been randomly (relatively homogeneously) chlorinated by using a swelling solvent and/or a chlorinating temperature above the crystalline melting temperature of the polyethylene. Traditionally those who chlorinated polyethylene wanted to eliminate the crystalline polyethylene phase by chlorinating the crystallizable polyethylene segments, which inhibits or prevents further crystallization of the polyolefin. Residual crystalline fractions in a chlorinated polyethylene would require a processing temperature above the melting point while amorphous polyethylene fractions can be processed at a lower temperature. The use of higher chlorination temperatures and swelling solvents (which decrease residual crystallinity) also increase the rate of the chlorinating reaction, thus reducing costs. It has even been postulated that highly crystalline polyethylene would not be effectively chlorinated unless either it was heated above the crystalline melting temperature or the crystallinity was reduced by using a swelling solvent.
Two articles were published in Polymer Engineering and Science, vol. 28 pp. 1167-1172 and 1173-1181, which tried to compare and contrast homogeneously chlorinated polyethylene and their blocky chlorinated polyethylene. The chlorination time for the blocky chlorinated polyethylene was continued through 20 hours. The authors postulated that during chlorination the crystalline polyethylene surfaces were chlorinated, converting them to amorphous chlorinated material. They observed that the melting point of the crystalline polyethylene was a function of crystalline thickness and the heat of melting (&Dgr;H) of the polyethylene decreased after about 20 wt. % chlorine was added. The crystalline thickness was limited after chlorination by the number of successive non-chlorinated methylene repeat units.
Various conventional impact modifiers have been used with PVC and CPVC such as ABS or MBS impact modifiers. Use of these impact modifiers can reduce other desirable properties of the PVC or CPVC such as heat distortion temperature, thermal stability, oxidation resistance, tensile strength and stability to ultraviolet (UV) light exposure. There have been neither publications nor commercial products (except for graft copolymers) that disclose or include polymers prepared by polymerizing blocks of two different monomers to use to compatibilize PVC or CPVC with polyolefins. There is a continuing need for a copolymer to improve the interaction of PVC and/or CPVC with polyolefin elastomers.
SUMMARY OF INVENTION
Chlorinated polyolefins (e.g. polyethylenes) can be prepared having from about 10 or 20 to about 60 wt. % bound chlorine based on the weight of the chlorinated polyolefin (e.g. polyethylene) and having from about 20 to about 99 wt. % residual crystallizable polyolefin (e.g. polyethylene) blocks and having a peak melting temperature from about 110 to about 140° C. wherein said wt. % residual crystallizable blocks are expressed as a percentage based on the weight of crystallizable polyolefin in the polymer before chlorination. Such chlorinated polyolefins (e.g. polyethylenes) can be prepared by a chlorination process from semi-crystalline polyolefin which comprises reacting the semi-crystalline polyolefin in a generally unswollen state at a temperature below its crystalline melting temperature with chlorine for a short period of time. Depending on the reaction conditions chosen (mostly time, chlorine pressure, and temperature), a free radical source, a catalyst, and/or UV radiation may be useful. When the reaction conditions are suitable for quick chlorination, then the amorphous portion of the polyolefin is highly chlorinated while the crystalline portion of the polyolefin is not significantly converted to amorphous chlorinated polyolefin.
Interfacial agents such as the blocky chlorinated polyethylene can improve the dispersibility of polyolefin elastomers in PVC and/or CPVC and improve the adhesion between the polyolefin elastomer phase and the PVC and/or CPVC. While applicants disclose a preferred method for preparing blocky chlorinated polyethylenes, it is anticipated that any blocky chlorinated polyolefin with significant residual crystallinity and with at least 10 wt. % bound chlorine will have some desirable compatibilizing of PVC and/or CPVC with polyolefin rubbers. The crystalline polyolefin blocks of the chlorinated polyolefin associate with and maybe even co-crystallize, as shown by differential scanning calorimetry (DSC), with segments from the polyolefin rubber while the amorphous chlorinated blocks of said chlorinated polyolefin associate with the PVC and/or CPVC.
REFERENCES:
patent: 2592763 (1952-04-01), Taylor
patent: 2890213 (1959-06-01), Noeske
patent: 2913449 (1959-11-01), Hoerger et al.
patent: 2928819 (1960-03-01), Noeske
patent: 3085082 (1963-04-01), Baer et al.
patent: 3396211 (1968-08-01), Bonotto
patent: 3454544 (1969-07-01), Young et al.
patent: 3563974 (1971-02-01), Eckardt et al.
patent: 3585117 (1971-06-01), Gresser et al.
patent: 3621080 (1971-11-01), De Coene
patent: 3940456 (1976-02-01), Frey et al.
patent: 4180529 (1979-12-01), Hofmann
patent: 4197386 (1980-04-01), Schoen
patent: 4234703 (1980-11-01), Lindsay
patent: 4425206 (1984-01-01), Hutchinson
patent: 4652616 (1987-03-01), Kamiya et al.
patent: 4751147 (1988-06-01), Stephens et al.
patent: 4767817 (1988-08-01), Lee
patent: 5229456 (1993-07-01), Ilenda et al.
patent: 5234993 (1993-08-01), Huynh-Ba
patent: 5270381 (1993-12-01), Yamanaka et al.
patent: 5308894 (1994-05-01), Laughner
patent: 5338803 (1994-08-01), Sun et al.
patent: 5340880 (1994-08-01), Backman et al.
patent: 5352735 (1994-10-01), Hofmann
patent: 5387648 (1995-02-01), Ainsworth
patent: 5446064 (1995-08-01), Hori et al.
patent: 5457146 (1995-10-01), Ogoe et al.
patent: 5460818 (1995-10-01), Park et al.
patent: 5464903 (1995-11-01), Hofmann
patent: 5478887 (1995-12-01), Huynh-Ba
patent: 5502111 (1996-03-01), Huynh-Ba
patent: 5525651 (1996-06-01), Ogoe et al.
patent: 5525679 (1996-06-01), Effler, Jr. et al.
patent: 822201 (1969-09-01), None
patent: 0131937 (1985-01-01), None
patent: 0343657 (1989-11-01), None
patent: 0612602 (1994-08-01), None
patent: 060618260 (1994-10-01), None
patent: 0695782 (1996-02-01), None
patent: 2381069 (1978-09-01), None
patent: 1144640 (1969-03-01), None
patent: 1161614 (1969-08-01), None
patent: 2172289 (1986-09-01), None
patent: 51-138791 (1976-11-01), None
patent: 58-4721 (1983-01-01), None
patent: 7290648 (1995-11-01), None
patent: 9309995 (1997-12-01), None
Journal of Applied Polymer Science, vol. VI, No. 19, pp. 20-31, 1962, Canterino et al., “Chlorinated and Chlorosulfonated Polyolefins”.
Polymer Engineering and Science, vol. 13, No. 3, May 1973,
Backman Arthur Leonard
Cinadr Bernard Frank
Detterman Robert Edwin
Lepilleur Carole Angele
Schmitz Theodore Joseph
Calloway Valerie L.
Dunlap Thoburn T.
The B. F. Goodrich Company
Wu David W.
Zalukaeva Tanya
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