Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-11-01
2001-05-15
Boykin, Terressa M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S271000, C528S272000
Reexamination Certificate
active
06232429
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method for making polyester carbonates. More particularly, the present invention relates to a melt condensation polymerization method involving the reaction of an aromatic dihydroxy compound, carbonic acid diester, and catalyst with a diacid.
Polyester carbonates and methods for their preparation have been studied extensively throughout the years. Polyester carbonates are thermoplastic resins that are clear and have high impact resistance. Due to their optical clarity and physical properties, polyester carbonates are used extensively in injection molding applications. The synthetic methods commonly used to made polyester carbonates are interfacial polymerization and melt condensation polymerization.
Interfacial polymerization is a well-known process. Fontana et al., U.S. Pat. No. 4,983,706, discuss the reaction of an aromatic dihydroxy compound such as bisphenol-A with phosgene and a diacid. The diacid is incorporated into the reaction mixture to produce a polyester carbonate melt flow such that the polyester carbonate is suitable for purposes of injection molding. Melt flow can also be described in terms of viscosity. Although the polyester carbonate produced by the interfacial method provides excellent viscosity for injection molding purposes, particulate contamination is often a problem. Additionally, the interfacial method uses a hazardous chemical, phosgene, and an environmentally hazardous chlorinated solvent.
Melt condensation polymerization is a known synthetic process which often results in less particulates found in the polymer compared to the interfacial method. Although melt condensation polymerization does not involve hazardous chemicals, the polyester carbonates made by the melt condensation polymerization process often do not have the flow properties of polyester carbonate made by the interfacial method.
In order to improve the flow properties of polyester carbonates made by the melt condensation polymerization process, different methods have been studied. Sakashitaet al. (Japanese Patent No. Hei 4[1992]-345616) discuss amethod for preparing polyester carbonates which incorporates aliphatic diacids directly into the polyester carbonate using a melt polymerization process. Sakashita et al. are concerned with polyester carbonates which incorporate the aromatic dihydroxy compound, 2,2,2′,2′-tetrahydro-3,3,3′,3′-tetramethyl- 1,1′-spirobi[1H-indene]-6,6′-diol, commonly known as SBI. In particular, Sakashita et al. are concerned with producing a polyester carbonate with a glass transition temperature greater than 100° C. In addition, this method involves the use of a cocatalyst, boric acid, to facilitate the incorporation of aliphatic diacids directly into polycarbonate via a melt process.
In co-pending U.S. application, Ser. No. 09/431,277, a method is described which involves the pre-reaction of a diacid, carbonic acid diester and catalyst wherein a diester is formed. An aromatic dihydroxy compound is then added to the pre-reaction mixture in order to form a polyester carbonate. Said application discusses a method which involves the presence of a pre-reactor to initially convert the diacid and carbonic acid diester into a new diester for subsequent conversion into a polyester carbonate. The addition of a diacid successfully improves the flow properties of the polyester carbonate formed, yet requires the presence of a pre-reactor in the melt condensation polymerization process.
An efficient method which does not require the pre-reaction of the diacid with carbonic acid diester has yet to be developed.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a melt condensation polymerization process for preparing polyester carbonates comprising the reaction of at least one aromatic dihydroxy compound, a carbonic acid diester and a catalyst with a diacid.
In one embodiment, the present invention provides a melt condensation polymerization process for preparing a polyester carbonate comprising the direct reaction of a diacid with a carbonic acid diester and a catalyst in the presence of at least one aromatic dihydroxy compound.
In a second embodiment, the present invention provides a melt condensation polymerization process for preparing a polyester carbonate comprising the direct reaction of a diacid with a carbonic acid diester and a catalyst in the presence of polycarbonate oligomers.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a melt condensation polymerization process for preparing a polyester carbonate which involves the reaction between at least one aromatic dihydroxy compound, a carbonic acid diester, a catalyst and a diacid. In one embodiment of the invention, the direct reaction of a diacid with the carbonic acid diester and the catalyst occurs in the presence of at least one aromatic dihydroxy compound. In a second embodiment, at least one aromatic dihydroxy compound is reacted with a carbonic acid diester and a catalyst to form a polycarbonate oligomer. The direct reaction of a diacid with the carbonic acid diester and the catalyst then occurs in the presence of the polycarbonate oligomer.
The composition of the present invention comprises a polyester carbonate comprising structural units of formula I:
wherein D is a divalent aromatic radical; and repeating or recurring units of the formula II:
—O—R
1
—O—D— (II)
wherein D has the meaning previously ascribed to it and R
1
is at least one divalent moiety selected from those of the formulae III, IV and V:
wherein X is a linear aliphatic group, branched aliphatic group, or cyclic aliphatic group. Linear and branched aliphatic groups are preferably those containing from 2 to about 20 carbon atoms, and include as illustrative non-limiting examples ethyl, propyl, isopropyl, butyl, tertiary-butyl, pentyl, neopentyl, hexyl, octyl, decyl, dodecyl. Cyclic aliphatic groups include cyclo- or bicycloalkyl radicals, preferably those containing from 3 to about 12 ring carbon atoms with a total number of carbon atoms less than or equal to 50. Some illustrative non-limiting examples of these cyclic aliphatic groups include cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, and cycloheptyl. Aliphatic groups also include aralkyl radicals containing from 7 to about 14 carbon atoms; these include, but are not limited to, benzyl, phenylbutyl, phenylpropyl, and phenylethyl.
The polyester carbonates which find use in the instant invention are well known in the art as disclosed in, for example, U.S. Pat. Nos. 3,030,331; 3,169,121; 3,207,814; 4,238,596; 4,238,597; 4,487,896; 4,506,065, and in copending application Ser. No. 09/181,902, filed Oct. 29, 1998, and assigned to the same assignee as the instant application.
Suitable aromatic dihydroxy compounds for preparing polyester carbonates include those represented by the formula VI:
HO—D—OH (VI)
wherein D is a divalent aromatic radical defined in formula I. Preferably, D has the structure of formula VII;
wherein A
1
represents an aromatic group such as phenylene, biphenylene, and naphthylene. E may be an alkylene or alkylidene group such as methylene, ethylene, ethylidene, propylene, propylidene, isopropylidene, butylene, butylidene, isobutylidene, amylene, amylidene, and isoamylidene. When E is an alkylene or alkylidene group, it may also consist of two or more alkylene or alkylidene groups connected by a moiety different from alkylene or alkylidene, such as an aromatic linkage; a tertiary amino linkage; an ether linkage; a carbonyl linkage; a silicon-containing linkage such as silane or siloxy; or a sulfur-containing linkage such as sulfide, sulfoxide, or sulfone; or a phosphorus-containing linkage such as phosphinyl or phosphonyl. In addition, E may be a cycloaliphatic group, such as cyclopentylidene, cyclohexylidene, 3,3,5-trimethylcyclohexylidene, methylcyclo-hexylidene, 2-[2.2.1]-bicycloheptylidene, neopentylidene, cyclopentadecylidene, cyclododecylidene, and adamantylidene. R
5
represen
Banach Timothy Edward
Davis Gary Charles
Lui Bill Kengliem
Bennett. Bernadette M.
Boykin Terressa M.
General Electric Company
Johnson Noreen C.
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