Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1989-08-26
1992-10-27
Seidleck, James J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
525132, 525392, 525905, C08L 7112
Patent
active
051590271
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
The present invention relates to a novel polyphenylene ether resin and a process for the preparation of the same. More particularly, the present invention relates to a novel polyphenylene ether resin in which the polyphenylene ether chains resin collectively contain at least a specific amount of terminal 6-chroman groups and which has an improved resistance to thermal oxidative deterioration at the time of processing and at the time of use at high temperatures, and also to a process for the preparation of the same. Furthermore, the present invention relates to a composition comprising this novel polyphenylene ether resin and a polystyrene resin.
2. Background Art
Polyphenylene ethers have excellent mechanical properties, electrical characteristics and heat resistance and, therefore, are widely used as thermoplastic molding materials. However, polyphenylene ethers have, as well as these advantageous properties, a disadvantage in that they are likely to undergo thermal oxidative deterioration. Accordingly, their use is limited in the fields where they are likely to undergo thermal oxidative deterioration. For obviating this disadvantage, uses of various stabilizers, such as amines and organic phosphorus compounds, have been proposed.
On the other hand, processes of modifying a polyphenylene ether per se have also been proposed. For example, Japanese Patent Publication Nos. 49-17679 and 49-48197 and the specification of U.S. Pat. No. 3,767,627 (Japanese Patent Publication No. 53-12553) teach that resistance to thermal oxidative deterioration is improved by blocking terminal phenolic groups of a polyphenylene ether by esterification, etherification or the like. With respect to polyphenylene ether resins modified by these processes, a stabilization is achieved, to a certain extent, in a film prepared by casting a solution of the modified resin in an organic solvent, but with respect to a test piece or film prepared by melt molding, a satisfactory stabilizing effect is not obtained.
The reason for this is considered to be as follows. For example, with respect to poly[oxy(2,6-dimethyl-1,4-phenylene)], which is commercially very important, a phenolic hydroxyl group shown in formula (e): ##STR1## is formed by heat applied in the melt molding and this phenolic hydroxyl group causes thermal oxidative deterioration as in the case of an uncapped phenolic hydroxyl group.
For obviating this disadvantage, a process has recently been proposed in which a hydroxyl group-blocking agent, such as a salicylic acid ester, is used at the melt molding (the specification of U.S. Pat. No. 4,760,118 and Japanese Patent Application Laid-Open Specification No. 63-295632). According to this process, the hydroxyl group of formula (e) is blocked as shown by formula (f) and a certain degree of improvement can be attained: ##STR2## However, the methylene group present between the two benzene rings, which is activated by these benzene rings and is very likely to undergo oxidation, is left as it is, and therefore, the resistance to thermal oxidation is still unsatisfactory. Furthermore, in this process, various by-products, which are likely to plasticize the polyphenylene ether resin, are formed, and the melt-molded product is likely to be plasticized by these by-products left in the melt-molded product. Therefore, another disadvantage arises in that in order to remove these by-products, the resin should be dissolved and subjected to a re-precipitation treatment.
DISCLOSURE OF THE INVENTION
In these situations, the present inventors have made extensive and intensive studies, and as a result, it has unexpectedly been found that when a 6-chroman group is present at a terminal of a polyphenylene ether, the stability of the polyphenylene ether resin in the melt molding is highly improved and such a partial structure as shown by the following formula (g): ##STR3## wherein R.sup.1 through R.sup.5 each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, an aryl group o
REFERENCES:
patent: 3361851 (1968-01-01), Gowan
patent: 3767627 (1973-10-01), Schoen et al.
patent: 3929930 (1975-12-01), Izawa et al.
patent: 3994856 (1976-11-01), Katchman
patent: 4054553 (1977-10-01), Olander
patent: 4092294 (1978-05-01), Bennett, Jr. et al.
patent: 4097556 (1978-06-01), Toyama et al.
patent: 4145377 (1979-03-01), Bussink
patent: 4166055 (1979-08-01), Lee, Jr.
patent: 4239673 (1980-12-01), Lee, Jr.
patent: 4242263 (1980-12-01), Lee, Jr.
patent: 4383082 (1983-05-01), Lee, Jr.
patent: 4528327 (1985-07-01), Cooper
patent: 4617346 (1986-10-01), Sonoda
patent: 4670537 (1987-06-01), White
patent: 4678839 (1987-07-01), Hallgren et al.
patent: 4760118 (1988-07-01), White et al.
patent: 4788277 (1988-11-01), Ibe et al.
patent: 4863997 (1989-09-01), Shibuya
patent: 4888397 (1989-12-01), van der Meer et al.
patent: 4933425 (1990-06-01), Gallucci
Martin, Robert W. "The Chemistry of Phenolic Resins." John Wiley & Sons, New York, 1956, (pp. 189, 190, 205).
Ibe Sadao
Kanayama Akihiro
Ueda Sumio
Asahi Kasei Kogyo Kabushiki Kaisha
Hamilton, III Thomas
Seidleck James J.
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