Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2001-05-09
2003-03-18
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
C525S507000, C528S096000, C528S099000, C549S520000
Reexamination Certificate
active
06534621
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a process for manufacturing an &agr;-halohydrin ester derivative of at least one or more phenols and converting such &agr;-halohydrin ester derivative to an epoxy resin.
More specifically, the present invention relates to a process for manufacturing an &agr;-halohydrin derivative and at least one or more phenols, converting such &agr;-halohydrin ester derivative to an &agr;-halohydrin intermediate of at least one or more phenols and utilizing such &agr;-halohydrin intermediate of the at least one or more phenols to make an epoxy resin. For example, the present invention is useful for manufacturing bisphenol A (bis A) epoxy resin.
&agr;-Halohydrins are made, as reactive intermediates, via several processes which are well known to those skilled in the art. Generally, the intermediate &agr;-halohydrins are subsequently converted into epoxides. In one widely practiced process, &agr;-halohydrins are made by reacting low molecular weight olefin-containing compounds such as propylene, butylene and allyl chloride, with halogens, such as chlorine or bromine, in water. The &agr;-halohydrins, more specifically the &agr;-chlorohydrins, from propylene, butylene and allyl chloride are subsequently used for manufacturing propylene oxide, butylene oxide and epichlorohydrin (ECH) respectively, in large scale. The process chemistries for the industrial processes of propylene oxide and ECH are outlined in the following reaction sequences, Reaction Sequence (I) and Reaction Sequence (II). More specifically, Reaction Sequence (I) shows a process chemistry scheme for industrial production of propylene oxide from chlorohydrins made via chlorine in water route; and Reaction Sequence (II) shows a process chemistry scheme for industrial production of epichlorohydrin from chlorohydrins made via chlorine in water route.
In a well-known industrial process for producing epoxy resins on a large commercial scale, in a first step, an &agr;-halohydrin, as a reactive intermediate, is made by reacting an active hydrogen-containing compound such as an alcohol, a phenol, a carboxylic acid or an amine with an epihalohydrin, such as epichlorohydrin (ECH) or epibromohydrin. Then, in a second step, the &agr;-halohydrin intermediate is converted into a glycidyl ether, glycidyl ester, or glycidyl amine under basic reaction conditions.
The most widely made and particularly useful epoxy resin is bisphenol A (bis A) epoxy resin which is made by the coupling reaction of bis A and ECH to form the bis(&agr;-chlorohydrin) intermediate in a first step. Then, in an epoxide ring-forming dehydrochlorination reaction with base, as a second step, the bis A bis(&agr;-chlorohydrin) intermediate is converted to the bis A diglycidyl ether epoxy resin. Such a two-step process for making an epoxy resin is described by H. Lee and K. Neville in “Handbook of Epoxy Resins”, McGraw-Hill Book Co., New York, New York, 1982, Reissue, 2-3 to 2-4. This process is shown in the following reaction sequence, Reaction Sequence (III). More specifically, Reaction Sequence (III) shows a process chemistry scheme for a two-step, industrial manufacture of bis A epoxy resin via the reaction of bis A and ECH to make a chlorohydrin intermediate.
The above two-step process of coupling bis A and ECH followed by epoxide ring forming dehydrochlorination has also been combined into a single-step reaction, wherein the bis(&agr;-chlorohydrin) intermediate of bis A is generated in situ and converted into an epoxy simultaneously. Such a single-step process for making bis A epoxy resin is described in U.S. Pat. Nos. 4,499,255; 4,778,863; and 5,028,686.
Another method to generate &agr;-chlorohydrins, as reactive intermeditates, is described in U.S. Pat. No. 2,144,612 in which glycerol, which is an &agr;-glycol, is converted into an &agr;-chlorohydrin by reaction with anhydrous hydrogen chloride (HCl) in the presence of a catalytic amount of acetic acid (AcOH). U.S. Pat. No. 2,144,612 describes a process that is shown in the following reaction sequence, Reaction Sequence (IV), for making glycerol dichlorohydrin, a precursor for epichlorohydrin from the &agr;-glycol glycerol. More specifically, Reaction Sequence (IV) shows chemistry for epichlorohydrin synthesis via the reaction of glycerol with HCl and AcOH to make glycerol dichlorohydrin.
Although epichlorohydrin (ECH) is an important commercial product for making &agr;-chlorohydrin intermediates, and particularly for making the bis A bis &agr;-chlorohydrin intermediate precursors of bis A epoxy resin, ECH provides a chlorine-intensive route to producing epoxy resins. In the predominate commercial process for making ECH, ECH is made from allyl chloride, which in turn, is made from thermal chlorination of propylene using chlorine gas, a process that produces chlorinated by-products. Generally, chlorinated by-products are treated as waste material.
Additionally, a large amount of water is used when converting allyl chloride into an &agr;-chlorohydrin intermediate, and this water must eventually also be treated as waste. Therefore, from an environmental standpoint, there is a desire to reduce the consumption of chlorine and to reduce the generation of chlorinated by-products and waste water in the production of epoxy resin.
In addition, epoxy resins made from ECH by either of the previously described two-step or single-step processes, may have a high organic chloride content which may be deemed as undesirable in some applications, for example, in electronic applications.
It is therefore desired to provide a non-epichlorohydrin process for making epoxy resins such as bis A epoxy resin. That is, it is desired to provide an alternative epoxy resin route, i.e., an alternative process without using ECH for manufacturing epoxy resins.
One non-epichlorohydrin process for manufacturing epoxy resins is described in U.S. Pat. No. 6,001,945. In the process of U.S. Pat. No. 6,001,945, glycidol is used as a reactant to produce an &agr;-glycol derivative, which is subsequently converted to an &agr;-chlorohydrin via reaction with hydrogen chloride and a catalytic amount of acetic acid via the process described in U.S. Pat. No. 2,144,612. Glycidol is known to be a highly toxic and thermally unstable material tending to explosively self-polymerize. At low temperatures, such as 70° C., glycidol is unstable and the loss of epoxide content of glycidol is significant. Glycidol self-polymerization diminishes glycidol selectivity and product yield in its reactions, and the glycidol self-polymerization products complicate separation and purification of the desired reaction product. These undesirable properties of glycidol are described in detail by A. Kleemann and R. Wagner in “Glycidol Properties, Reactions, Applications”, Dr. Alfred Huthig Verlag, New York, New York, 1981, pp. 48-52. Thus, it is desirable to develop processes that can manufacture &agr;-halohydrin intermediates as precursors for manufacturing epoxy resins that do not require glycidol as a reactant.
SUMMARY OF THE INVENTION
One aspect of the present invention is directed to a process for making an epoxy resin by converting an &agr;-halohydrin ester derivative of a phenol or mixture of phenols to an epoxy resin.
Another aspect of the present invention is directed to a process for manufacturing an &agr;-halohydrin intermediate of at least one or more phenols using an in situ halide substitution-deesterification process to convert an &agr;-hydroxy ester derivative of at least one or more phenols to the &agr;-halohydrin intermediate. The process is preferably carried out under anhydrous conditions with an anhydrous hydrogen halide such as hydrogen chloride, hydrogen bromide, or hydrogen iodide, as a reactant; and optionally, the process is carried out in the presence of a solvent.
Yet another aspect of the present invention is directed to an alternative, non-epichlorohydrin process for manufacturing an epoxy resin of at least one or more phenols utilizing, as an intermediate product, the &agr;-halohydrin intermediate of at
Boriack Clinton J.
Liao Zeng K.
Dow Global Technologies Inc.
Sellers Robert E.L.
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