Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From organic oxygen-containing reactant
Reexamination Certificate
2002-09-10
2004-12-07
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From organic oxygen-containing reactant
C528S086000, C528S090000, C528S102000, C528S391000, C528S487000, C528S488000
Reexamination Certificate
active
06828414
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing an aromatic polyether obtainable by polymerizing a biphenol and a dihalogenodiphenyl sulfone in diphenyl sulfone in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate.
2. Description of Related Art
Aromatic polyethers containing a repeating unit represented by the formula (1-1):
are useful as high molecular compounds superior in heat resistance, impact resistance and others. As processes for producing them, there have been known processes in which 4,4′-biphenol is polymerized with a 4,4′-dihalogenodiphenyl sulfone represented by the formula (2):
wherein each of x
1
and x
2
independently represents a halogen, in diphenyl sulfone and in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate to produce an aromatic polyether represented by the formula (1):
wherein each of x
1
and x
2
have the same meaning as above, and n represents an integer of 1 or above (JP-A-3-84032).
In the above process, when a 4,4′-dihalogenodiphenyl sulfone (2) is used in an amount exceeding 1 time by mole and not exceeding 1.05 time by mole, aromatic polyethers represented by the above formula (1) having a higher molecular weight, such as those having a weight-average molecular weight of 35,000 or more, can be obtained. However, although an aromatic polyether having such a desired high molecular weight can be obtained, a problem arises that the obtained aromatic polyether has a greater dispersion of molecular weight, which tends towards an inferior impact resistance.
An object of the present invention is to provide a process for producing an aromatic polyether having high molecular weight as well as small dispersion of molecular weight by polymerizing a biphenol with a dihalogenodiphenyl sulfone in diphenyl sulfone and in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate.
Under these circumstances, the inventors have conducted an intensive research for developing a process which allows production of aromatic polyethers with a high molecular weight and a small dispersion of the molecular weight by polymerizing 4,4′-biphenol with a 4,4′-dihalogenodiphenyl sulfone in diphenyl sulfone and in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate. As the result, they have found the fact that the above problems can be solved when the polymerization is carried out at a specific temperature. The inventors have further found that aromatic polyethers having improved transparency can be obtained in the above process by using hypophosphorous acid and/or its alkali metal salts. Thus, the present invention was completed.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a process for producing an aromatic polyether represented by the above formula (1) which comprises polymerizing 4,4′-biphenol with a 4,4′-dihalogenodiphenyl sulfone represented by the above formula (2)
in an amount exceeding 1 time by mole and not exceeding 1.05 time by mole based on said 4,4′-biphenol
in diphenyl sulfone and
in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate
at a temperature which is not lower than 240° C. and not higher than 270° C.
The present invention further provides a process for producing an aromatic polyether represented by the above formula (1) which comprises polymerizing 4,4′-biphenol with a 4,4′-dihalogenodiphenyl sulfone represented by the above formula (2)
in an amount exceeding 1 time by mole and not exceeding 1.05 time by mole based on said 4,4′-biphenol
in diphenyl sulfone,
in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate and
in the presence of hypophosphorous acid and/or its alkali metal salts in an amount exceeding 0.001 time by mole and not exceeding 0.006 time by mole based on said 4,4′-biphenol at a temperature which is not lower than 240° C. and not higher than 270° C.
REFERENCES:
patent: 5212264 (1993-05-01), Hoffmann et al.
patent: 6228970 (2001-05-01), Savariar
patent: 2002/0010307 (2002-01-01), Schwab
patent: 9-316189 (1997-12-01), None
patent: 2002-220469 (2002-08-01), None
Okamoto Kazushige
Satoh Kunihisa
Sughrue & Mion, PLLC
Sumitomo Chemical Company Limited
Truong Duc
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