Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
1995-06-22
2001-08-21
Sellers, Robert E. L. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S176000, C528S219000, C568S628000
Reexamination Certificate
active
06277944
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to alkylated and/or aralkylated polyhydroxy aromatic compounds and to processes for their preparation and use.
2. Description of Related Art
Polyhydroxy aromatic compounds are employed, in particular, in polymer chemistry as starting materials for the preparation of polycarbonates, polyesters, polyethers, and epoxy resins. The term polyhydroxy aromatic compounds refers hereinafter to aromatic compounds having two or more hydroxyl groups in the molecule. The aromatic compounds may be mono- or polycyclic, and as structural elements may also include any desired combinations of individual and fused rings, and divalent groups such as (thio)ether bridges, carbonyl groups, sulfonyl groups, carboxamido groups, and/or alkylene groups.
Whereas, for example, the polycarbonates and polyphthalates derived from bisphenol A are readily soluble in aromatic solvents, the solubility in aromatic solvents of the epoxy resins which are conventional in industry is low or nonexistent. The aliphatic ethers which are suitable as solvents for epoxy resins, examples of which include methoxypropanol, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, on the one hand, are considerably more expensive than conventional solvents and, on the other hand, tend to form peroxides in contact with atmospheric oxygen. They are therefore more complex to handle and constitute a safety hazard.
Attempts previously have been made to obtain modified phenols by substitution of phenols with aryl radicals or aralkyl radicals. For instance, DE-A 19 40 220 describes a process for the preparation of aralkyl phenols by reacting an aromatic vinylidene compound with a phenol, with catalysis by acids or Friedel-Crafts catalysts.
Austrian Patent AT 284 444 discloses the reactions of substituted or unsubstituted styrenes with phenols. In these reactions, the vinyl group of the styrenes is added on ortho or para to the OH group of the phenol. The reaction is in general accelerated by using Friedel-Crafts catalysts, for example, acids and metal halides. Depending on the conditions, catalysts and proportions of the reactants which are employed in this reaction, mono-, di- or tristyrenized phenols are obtained. See page 1, lines 23 to 29. Under the conditions of the Friedel-Crafts reaction, however, isomerization reactions also take place. For example, in the case of the bis- or poly (hydroxyphenyl) alkanes, the bond between the aromatic compound and the alkylene group is broken under the reaction conditions, leading to isomerization reactions. Mixtures of polyhydroxy aromatic compounds with very different substitution patterns are obtained, and in some cases phenol or other highly volatile hydroxy aromatic compounds also are given off. Depending on the temperature, duration and conditions of the reaction, highly crosslinked brittle products or rubber-like, tacky products are obtained if the hydroxy aromatic compounds obtained in this way are reacted with epichlorohydrin or with diglycidyl compounds to give epoxy resins.
For the purpose of modifying phenols as starting compounds for epoxide base structures, methods of ring alkylation have been described, for example with olefins (K.-D. Bode in Houben-Weyl: Methoden der Organischen Chemie [Methods of organic chemistry], 4th edition, Vol. 6/1c, p. 955 ff., Georg Thieme Verlag, Stuttgart 1976). The preparation of epoxides therefrom is carried out, for example, as indicated in U.S. Pat. No. 4,594,398, wherein cationic alkylation of phenol with aliphatic dienes in the presence of catalysts is followed by reaction with epichlorohydrin to give the diglycidyl ether and resulting thereby in bisepoxides being obtained. By means of these substitution reactions, alkyl groups additionally are introduced without, however, improving the solubility in aromatic hydrocarbons. The reaction products are not uniform structures, but represent mixtures of polyhydroxy aromatic compounds with various substitution patterns and a varying number of hydroxyl groups in the molecule.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to modify polyhydroxy aromatic compounds in such a way that the solubility in aromatic solvents of the polycondensation products prepared therefrom is improved, while retaining the otherwise good level of properties of polymers prepared therefrom.
It is also an object of the invention to find a process for alkylation and aralkylation which can be applied to the above-mentioned polyhydroxy aromatic compounds and which leads to uniform products without rearrangement and without elimination of phenol(s).
It is also an object of the invention to provide polyhydroxy compounds of improved solubility, and to provide polycondensation polymers prepared from such compounds.
In accordance with these and other objects, there is provided a process for the preparation of alkylated and/or aralkylated polyhydroxy aromatic compounds comprising reacting a polyhydroxy aromatic compound (A) with an alkene and/or aralkene compound (B) at a temperature above room temperature in the presence of a mixture (C) of oxalic acid and boric acid in a molar ratio of from 1:5 to 1:0.
In accordance with these and other objects of the invention, there also is provided an alkylated and/or aralkylated polyhydroxy aromatic compound obtained by the process described above.
In accordance with other aspects of the invention, there are provided condensation polymers, such as polyesters, polycarbonates, epoxy resins, and aromatic polyethers, prepared from alkylated and/or aralkylated polyhydroxy aromatic compounds as described above.
Further objects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments that follows.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the experiments to achieve the objects on which the invention is based, it was found that formic acid, acetic acid and higher carboxylic acids, alone or mixed with boric acid, possess no catalytic activity for the alkylation and aralkylation reaction. In spite of this, it surprisingly was found by the present inventors that the use of oxalic acid and boric acid provides alkylated and aralkylated polyhydroxy aromatic compound.
The invention provides a process for the preparation of alkylated and aralkylated polyhydroxy aromatic compounds by reaction of a polyhydroxy aromatic compound (A) with an alkene compound (B) at elevated temperature with the addition of a mixture (C) of oxalic acid and boric acid in a molar ratio of from 1:5 to 1:0, preferably from 1:2 to 1:0.1 and, in particular, from 1:1 to 1:0.5.
The invention also provides the alkylated and/or aralkylated polyhydroxy aromatic compounds prepared by this process.
The reaction can be carried out in any desired manner, for example, in the melt (bulk process) or in an inert, high-boiling solvent. These solvents have boiling temperatures of at least 80° C.
The reaction is carried out at any desired elevated temperature, that is, a temperature above room temperature which is, for example, at a temperature of from 80 to 180° C., preferably from 100 to 170° C. and, with particular preference, from 120 to 160° C.
In order to avoid oxidative degradation of the starting materials and products, the reaction preferably is carried out under a protective gas, such as nitrogen and/or argon. It also is possible to work under pressure, for example, if low-boiling starting materials are employed.
Any desired polyhydroxy aromatic compounds or mixtures thereof may be used. Polyhydroxy aromatic compounds which are particularly suitable for the invention are dihydroxy and trihydroxy aromatic compounds. Any known compounds of these types are useful.
Examples of suitable dihydroxy aromatic compounds include, but are not limited to, bis(4-hydroxyphenyl) (cyclo)alkanes such as 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane and -ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, the corresponding compounds derived from n
Foley & Lardner
Sellers Robert E. L.
Solutia Germany GmbH & Co. KG
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