Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1999-12-27
2002-02-12
Acquah, Samuel A. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S176000, C528S182000, C528S185000, C528S194000, C528S295300, C528S302000, C528S307000, C528S308000, C528S308600, C525S437000, C525S439000, C524S186000, C524S401000
Reexamination Certificate
active
06346597
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 followed by a solid state polymerization method to produce polyester carbonates.
Polyester carbonates and methods for their preparation have been studied extensively throughout the years. Polyester carbonates are typically 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. One such process is described in Fontana et al., U.S. Pat. No. 4,983,706 which discusses the reaction of an aromatic dihydroxy compound such as bisphenol-A with phosgene and a diacid to make polyester carbonates. The diacid is incorporated into the reaction mixture to produce a polyester carbonate with 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 may be a problem. Additionally, the above-mentioned process 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. The melt condensation polymerization to prepare polyester carbonates does not involve hazardous chemicals. However, the polyester carbonates made by the melt condensation polymerization process often do not have the flow properties of polyester carbonates 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. Sakashita et al. (Japanese Patent No. Hei 4[1992]-345616) discuss a method for preparing polyester carbonates which incorporates aliphatic diacids directly into a 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 [1 H-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 150° C. In addition, this method involves the use of a cocatalyst, boric acid, to facilitate the incorporation of aliphatic diacids directly into polymer via a melt process.
New and more efficient methods for preparing polyester carbonates which can be used for injection molding purposes are constantly being sought.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a process for preparing a polyester carbonate. The process comprises the steps of:
(A) reacting a diacid with a carbonic acid diester and a catalyst in the presence of a polycarbonate oligomer via melt condensation polymerization to form a pre-polymer; and
(B) reacting the pre-polymer via solid state polymerization to form polyester carbonates.
DETAILED DESCRIPTION OF THE INVENTION
It has been found that the combination of the melt condensation polymerization method and solid state polymerization method can be used to form polyester carbonates containing thermally sensitive monomers. A diacid is incorporated into the polymer via a melt condensation polymerization reaction of diacid with a carbonic acid diester and a catalyst in the presence of polycarbonate oligomers to form a pre-polymer. The reaction of the carbonic acid diester and/or the polycarbonate oligomers with the diacid and catalyst forms a pre-polymer containing carboxylic diesters. “Pre-polymer” as used herein refers to the mixture of the reacted carbonic acid diester, diacid and catalyst in the presence of polycarbonate oligomers. Once the pre-polymer is formed, high molecular weight polyester carbonates are formed via a solid state polymerization method. “High molecular weight polyester carbonates” as used herein refers to polyester carbonates with a number average molecular weight greater than about 10,000 grams per mole.
Polyester carbonates of the present invention comprise polycarbonate structural units of formula I:
wherein D may be 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 about 2 to about 20 carbon atoms, and include as illustrative non-limiting examples ethyl, propyl, isopropyl, butyl, sec-butyl, pentyl, neopentyl, hexyl, octyl, decyl, and dodecyl. Cyclic aliphatic groups include cyclo- or bicycloalkyl radicals, preferably those containing from about 3 to about 12 ring carbon atoms with a total number of carbon atoms less than or equal to about 50. Some illustrative non-limiting examples of cyclic aliphatic groups include cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, and cycloheptyl. Aliphatic groups also include aralkyl radicals containing from about 7 to about 14 carbon atoms; these include, but are not limited to, benzyl, phenylbutyl, phenylpropyl, and phenylethyl.
Illustrative polyester carbonates can be made by the method of the instant invention are disclosed in 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 and polycarbonate oligomers include those represented by the formula VI:
HO—D—OH (VI)
wherein D may be a divalent aromatic radical defined in formula I. At least about 50 percent of the total number of D groups are aromatic organic radicals and the balance thereof are aliphatic, alicyclic, or aromatic organic radicals. 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
represents hydrogen or a monovalent hydrocarbon group such as alkyl, aryl, aralkyl, alkaryl, cycloalkyl, or bicycloalkyl. The term “alkyl” is intended to designate both straight-chain alkyl and branched alkyl radicals. Straight-chain and branched alkyl radicals are preferably those containing from about 2 to about 20 carbon atoms, and include as illustrative non-limiting examples ethyl, propyl, isopropyl, butyl, tertiary-butyl, pentyl, neopentyl, hexyl, octyl, decyl, and dodecyl. Aryl radicals in
Banach Timothy Edward
Gillette Gregory Ronald
Acquah Samuel A.
Bennett Bernadetta M.
General Electric Company
Johnson Noreen J.
LandOfFree
Method for making polyester carbonates does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for making polyester carbonates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for making polyester carbonates will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2936935