WO2009064707A1

WO2009064707A1 - Process for preparing advanced epoxi resins

Info

Publication number: WO2009064707A1
Application number: PCT/US2008/083085
Authority: WO
Inventors: Shawn J. Maynard; Matthew W. Cosby; Patrick M. Cooke; Paul A. Gillis
Original assignee: Dow Global Technologies Inc.
Priority date: 2007-11-15
Filing date: 2008-11-11
Publication date: 2009-05-22
Also published as: TW200932778A

Abstract

A process for producing a converted epoxy resin from the catalyzed reaction between an aromatic phenol such as bisphenol A and a liquid epoxy resin. The process is essentially adiabatic and requires rapid, through mixing.

Description

PROCESS FOR PREPARING ADVANCED EPOXI RESINS

BACKGROUND OF THE INVENTION

The instant invention relates to processes for converting an epoxy resin that is a liquid at room temperature to an epoxy resin that is a solid at room temperature.

Epoxy resin coatings can be formed from coating formulations comprising an epoxy resin that is a liquid at room temperate (~ 25° C) or comprising an epoxy resin that is a solid at room temperature. Epoxy resins that are a solid at room temperature are used, for example, in powder coating formulations. An epoxy resin that is a liquid at room temperature (such as the well known liquid epoxy resin formed from the reaction between epichlorohydrin with bisphenol A) can be converted into an epoxy resin that is a solid at room temperature by mixing the liquid epoxy resin with an aromatic phenol (preferably a bisphenol such as bisphenol A) in the presence of a catalyst and then heating the mixture so that the liquid epoxy resin catalytically reacts with the aromatic phenol to convert the liquid epoxy resin into an epoxy resin that is a solid at room temperature. For example, the above- described epichlorohydrin/bisphenol A liquid epoxy resin can catalytically react with bisphenol A to produce an epoxy resin that is a solid at room temperature. It would be an advance in the art of converting such a liquid epoxy resin to a solid epoxy resin ("converted epoxy resin") if the process were improved to reduce the time needed for such conversion.

SUMMARY OF THE INVENTION

The instant invention is a solution to the above-mentioned problem. The time required to convert a liquid epoxy resin to an epoxy resin that is a solid at room temperature is reduced by as much as about 23% or more using the process of the instant invention.

In one embodiment, the instant invention is a process for producing a converted epoxy resin, comprising the steps of: (a) heating a liquid epoxy resin to produce a heated liquid epoxy resin; (b) heating an aromatic phenol to produce a heated aromatic phenol; (c) mixing the heated liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a mixture of liquid epoxy resin and aromatic phenol having a temperature in the range of from about 11O⁰C to about 14O⁰C; and (d) mixing (i) a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with (ii) the mixture of liquid epoxy resin and aromatic phenol to increase the rate of reaction of the aromatic phenol with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with the mixture of liquid epoxy resin and aromatic phenol is greater than about 0.95 in less than about 20 seconds.

In another embodiment, the instant invention is a process for producing a converted epoxy resin, comprising the steps of: (a) heating a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with liquid epoxy resin to produce a heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin; (b) heating an aromatic phenol to produce heated aromatic phenol; and (c) mixing the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol is greater than about 0.95 in less than about 20 seconds. In yet another embodiment, the instant invention is a process for producing a converted epoxy resin, comprising the steps of: (a) heating a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with an aromatic phenol to produce a heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin; (b) heating liquid epoxy resin to produce heated liquid epoxy resin; and (c) mixing the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin is greater than about 0.95 in less than about 20 seconds. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in the detailed description which follows, in reference to the figures of drawings by way of non-limiting examples of exemplary embodiments of the present invention, wherein:

Figure 1 is a side cross-sectional view of a prior art reactor and process;

Figure IA is a top cross-sectional view taken along line IA- IA of the prior art reactor of Figure 1.

Figure 2 is a side cross-sectional view of a reactor and process of the instant invention; and

Figure 2A is a top cross-sectional view taken along line 2A-2A of the present invention reactor of Figure 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The term "uniformity of composition" (U) is defined herein by the following equation:

U = I - (([C-fully mixed] - [C-instantaneous])/C-fully-mixed); wherein [C-fully mixed] = the concentration of an additive (tracer) after complete mixing; and [C-instantaneous] = instantaneous concentration of additive. Thus, U = I means a completely homogeneous mixture.

The term "essentially without the addition of deletion of heat" means that any addition or deletion of heat is less than about ten percent (10 %) of the heat energy of the mixture. Preferably, any addition or deletion of heat is incidental and less than about five percent (5%) of the heat energy of the mixture. In one embodiment, the instant invention is a process for producing converted epoxy resin, comprising four steps. The first step is to heat liquid epoxy resin to produce heated liquid epoxy resin. The second step is to heat an aromatic phenol to produce heated aromatic phenol. The third step is to mix the heated liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a mixture of liquid epoxy resin and aromatic phenol having a temperature in the range of from about 11O⁰C to about 14O⁰C. The fourth step is to mix a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with the mixture of liquid epoxy resin and aromatic phenol to increase the rate of reaction of the aromatic phenol with the liquid epoxy resin to produce the converted epoxy resin, the uniformity of composition of the material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with the mixture of liquid epoxy resin and aromatic phenol being greater than about 0.95 in less than about 20 seconds; and preferably, being greater than about 0.95 in less than about 15 seconds. If such mixing is performed in a batch reactor having a rotating impeller, the rotating impeller is preferably from about five to about fourteen inches below the level of the mixture. Mixing the heated liquid epoxy resin and the heated aromatic phenol essentially without the addition (or deletion) of heat energy is important in the instant invention to increase the productivity of the process and to minimize the formation of solid phase encrustation of the container of the reaction. Requiring that the uniformity of composition of the mixing of the material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with the mixture of liquid epoxy resin and aromatic phenol be greater than about 0.95 in less than about 20 seconds reduces gel formation. In another embodiment, the instant invention is a process for producing converted epoxy resin, comprising three steps. The first step is to heat a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with liquid epoxy resin to produce a heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin. The second step is to heat an aromatic phenol to produce heated aromatic phenol. The third step is to mix the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin, the uniformity of composition of the mixing of the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol being greater than about 0.95 in less than about 20 seconds; and preferably, being greater than about 0.95 in less than about 15 seconds. If such mixing is performed in a batch reactor having a rotating impeller, the rotating impeller is preferably from about five to about fourteen inches below the level of the mixture. Mixing the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol essentially without the addition (or deletion) of heat energy is important in the instant invention to increase the productivity of the process and to minimize the formation of solid phase encrustation of the container of the reaction. Requiring that the uniformity of composition of the mixing be greater than about 0.95 in less than about 20 seconds reduces gel formation.

In yet another embodiment, the instant invention is a process for producing converted epoxy resin, comprising three steps. The first step is to heat a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with an aromatic phenol to produce a heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin. The second step is to heat liquid epoxy resin to produce heated liquid epoxy resin. The third step is to mix the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin, the uniformity of composition of the mixing of the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin being greater than about 0.95 in less than about 20 seconds; and preferably, being greater than about 0.95 in less than about 15 seconds. If such mixing is performed in a batch reactor having a rotating impeller, the rotating impeller is preferably from about five to about fourteen inches below the level of the mixture. Mixing the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin essentially without the addition (or deletion) of heat energy is important in the instant invention to increase the productivity of the process and to minimize the formation of solid phase encrustation of the container of the reaction. Requiring that the uniformity be greater than about 0.95 in less than about 20 seconds reduces gel formation.

Although any epoxy resin that is a liquid at room temperature can be used in the instant invention (including a liquid epoxy-novolac resin), a liquid epoxy resin comprising the reaction product of two moles of epichlorohydrin with one mole of bisphenol A is preferred. Although any aromatic phenol can be used in the instant invention, a bisphenol (such as bisphenol A) is preferred. Although many materials are known to increase the rate of reaction between a liquid epoxy resin and an aromatic phenol, ethyl triphenylphosphonium acetate is preferred and can be employed, for example, as a solid, as a solution in, for example, methanol or Dowanol DB. Preferably, the following amounts are used in the instant invention: from about 51 wt % to about 80 wt % liquid epoxy resin; from about 49 wt % to about 20 wt % aromatic phenol; and from about 100 parts per million to about 2000 parts per million catalyst. Additional ingredients, such as flow modifiers, toughening agents, and solvents, can be added to the reactants and/or the reaction product.

The term "liquid epoxy resin" herein means a composition that is a liquid at room temperature and which possesses one or more vicinal epoxy groups per molecule, i.e. at least one 1,2-epoxy group per molecule. In general, such compound is a saturated or unsaturated aliphatic, cycloaliphatic, aromatic or heterocyclic compound which possesses at least one 1,2-epoxy group. Such compound can be substituted, if desired, with one or more non-interfering substituents, such as halogen atoms, hydroxy groups, ether radicals, lower alkyls and the like.

Liquid epoxy resins useful in the present invention are well known in the art. Illustrative polyepoxide compounds useful in the practice of the present invention are described in the Handbook of Epoxy Resins by H. E. Lee and K. Neville published in 1967 by McGraw-Hill, New York and U.S. Patent No. 4,066,628, incorporated herein by reference.

Particularly useful compounds which can be used in the practice of the present invention are liquid epoxy resins having the following formula:

wherein n has an average value of from 0 to 2.

The epoxy resins useful in the present invention may include, for example, the glycidyl polyethers of polyhydric phenols and polyhydric alcohols. As an illustration of the present invention, examples of known epoxy resins that may be used in the present invention, include for example, the diglycidyl ethers of resorcinol, catechol, hydroquinone, bisphenol, bisphenol A, bisphenol AP (l,l-bis(4-hydroxylphenyl)-l-phenyl ethane), bisphenol F, bisphenol K, tetrabromobisphenol A, phenol-formaldehyde novolac resins, alkyl substituted phenol-formaldehyde resins, phenol-hydroxybenzaldehyde resins, cresol- hydroxybenzaldehyde resins, dicyclopentadiene-phenol resins, dicyclopentadiene- substituted phenol resins tetramethylbiphenol, tetramethyl-tetrabromobiphenol, tetramethyltribromobiphenol, tetrachlorobisphenol A and any combination thereof.

Examples of diepoxides particularly useful in the present invention include diglycidyl ether of 2,2-bis(4-hydroxyphenyl) propane (generally referred to as bisphenol A) and diglycidyl ether of 2,2-bis(3,5-dibromo-4-hydroxyphenyl) propane (generally referred to as tetrabromobisphenol A). Mixtures of any two or more polyepoxides can also be used in the practice of the present invention.

Other diepoxides which can be employed in the practice of the present invention include the diglycidyl ethers of dihydric phenols, such as those described in U.S. Patent Nos. 5,246,751; 5,115,075; 5,089,588; 4,480, 082 and 4, 438,254, all of which are incorporated herein by reference, or the diglycidyl esters of dicarboxylic acids such as those described in U. S. Patent No. 5,171,820. Other suitable diepoxides include for example, αω-diglycidyloxyisopropylidene-bisphenol-based epoxy resins (commercially known as D.E.R.® 300 and 600 series epoxy resins, products of The Dow Chemical Company, Midland, Michigan).

The epoxy resins which can be employed in the practice of the present invention also include liquid epoxy resins prepared either by reaction of diglycidyl ethers of dihydric phenols with dihydric phenols or by reaction of dihydric phenols with epichlorohydrin (also known as "taffy resins").

Preferred epoxy resins useful in the present invention include, for example, the diglycidyl ethers of bisphenol A; 4,4'- sulfonyldiphenol; 4,4- oxydiphenol; 4,4'- dihydroxybenzophenone; resorcinol; hydroquinone; 9,9'- bis(4-hydroxyphenyl)fluorene; 4,4'-dihydroxybiphenyl or 4, 4'-dihydroxy-α-methylstilbene and the diglycidyl esters of the dicarboxylic acids mentioned previously.

Other useful epoxide compounds which can be used in the practice of the present invention are cycloaliphatic epoxides. A cycloaliphatic epoxide consists of a saturated carbon ring having an epoxy oxygen bonded to two vicinal atoms in the carbon ring for example as illustrated by the following general formula:

wherein R is a hydrocarbon group optionally comprising one or more heteroatoms (such as, without limitation thereto Cl, Br, and S), or an atom or group of atoms forming a stable bond with carbon (such as, without limitation thereto, Si, P and B) and wherein n is greater than or equal to 1.

The cycloaliphatic epoxide may be a monoepoxide, a diepoxide, a polyepoxide, or a mixture of those. For example, any of the cycloaliphatic epoxide described in U.S. Patent No. 3,686,359, incorporated herein by reference, may be used in the present invention. As an illustration, the cycloaliphatic epoxides that may be used in the present invention include, for example, (3,4-epoxycyclohexyl-methyl)-3,4-epoxy- cyclohexane carboxylate, bis-(3,4-epoxycyclohexyl) adipate, vinylcyclohexene monoxide and mixtures thereof.

Materials capable of catalyzing the stated reaction are well-known in the art and reference is made thereto for the purposes of this invention. Illustrative catalysts are set forth in U.S. Patent Nos. 2,216,099; 2,633,458; 2,658,855; 3,377,406; 3,694,407; 3,948,855; 4,389,520; 4,354,015; and 3,477,990 and The Handbook of Epoxy Resins by H. Lee and K. Neville, published in 1967 by McGraw-Hill, New York, all of which are incorporated herein by reference. Representative of the described catalysts are secondary and tertiary amines, preferably tertiary amines such as benzyl dimethyl amine, triethyl amine and benzyl diethyl amine; the alkali metal hydroxides e.g., potassium hydroxide; quaternary ammonium compounds such as tetralkylammonium halides, e.g., tetramethyl ammonium chloride and phosphines and quaternary phosphonium salts such as triphenyl phosphine and ethyltriphenyl phosphonium acetate-acetic acid complex.

The catalyst is typically employed in conventional amounts. These amounts will vary depending on the specific catalyst, polyepoxide and aromatic phenol employed but will preferably vary from about 0.005 to about 1 weight percent based on the total weight of the aromatic phenol and polyglycidyl ether components. More preferably, from about 0.01 to about 0.5 weight percent of the catalyst is employed, said weight percent being based on the total weight of the aromatic phenol and polyepoxide components.

Referring now to Figure 1, therein is shown a system 10 of the prior art. The system 10 includes a batch reactor 11 having a heating jacket 14. A heat transfer fluid (such as steam or a heated liquid) is introduced into the jacket 14 via nozzle 15 and out of the jacket 14 via nozzle 16. The reactor 11 has one or more stationary baffles 17 (two are shown in Fig. 1) mounted to the reactor inside walls. A motor 18 rotates shaft 19. An upper impeller and a lower impeller, 20a and 20b respectively, are mounted on the shaft 19. The components of the reaction mixture 21 are introduced into the reactor 11 via nozzle 12 and heated to the desired temperature. A catalyst is added to the reaction mixture 21; and as the reaction progresses it may even be desired to flow a coolant, instead of a heated liquid, via nozzle 15 into the jacket 14 to remove heat from the heat of reaction of the components of the reaction mixture 21. When the density of the reactive components 21 is 1.1 grams per cubic centimeter, when the viscosity of the reactive components 21 is 20 centipoise and when the motor 18 is operated at full power, the uniformity of composition of the components of reaction mixture 21 is about 0.95 in about 33 seconds. Product is flowed out from reactor 11 by way of nozzle 13.

Referring now to Figure 2, therein is shown a system 30 of the instant invention including a batch reactor 31. A portion (for example, about 75 wt%) of heated components 38 are introduced into the reactor 31 by way of the nozzle 32. The reactor 31 has one or more stationary baffles 34 (two are shown in Fig. 2) mounted to the reactor inside walls. A motor 35 rotates shaft 36. Upper impeller 37a and lower impeller 37b are mounted on the shaft 36. The level 39 of the heated components 38 in the reactor 31 is a distance "x" of between about 5 inches and about 14 inches (about 13 centimeters and about 35 centimeters) above the upper impeller 37a. When the density of the reactive components 38 is 1.1 grams per cubic centimeter, when the viscosity of the reactive components 38 is 20 centipoise and when the motor 35 is operated at full power, the uniformity of composition of the components of reaction mixture 38 is about 0.95 in 10 seconds. The remaining amount of heated components are then added to the reactor and the reaction proceeds. Product is flowed out from reactor 31 by way of nozzle 33. In Figure 2, only one inlet nozzle 32 and one outlet 33 is shown as described above with reference to the present invention. However, the present invention has been described above in relation with its preferred embodiments, and therefore other alternatives such as the use of one or multiple nozzles may be used for the inlet nozzle 32 and outlet nozzle 33, respectively, for the reactor 31. In addition, the impellers 37a and 37b may include multiple impellers for the reactor 31. It is understood by one skilled in the art that the present invention is not limited to the illustration in Figure 2; and that other alternatives, modifications and equivalents are included within the scope of the present invention.

The following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

EXAMPLE 1

Seventy five weight percent of a charge of 7683 pounds of heated liquid epoxy resin and 2516 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 13O⁰C, then 8.4 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 19O⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid.

EXAMPLE 2

Seventy five weight percent of a charge of 7510 pounds of heated liquid epoxy resin and 2740 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 125⁰C, then 7.6 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 195⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid.

EXAMPLE 3

Seventy five weight percent of a charge of 6892 pounds of heated liquid epoxy resin and 3167 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 127⁰C, then 12.3 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 22O⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid.

EXAMPLE 4 Seventy five weight percent of a charge of 7278 pounds of heated liquid epoxy resin and 2934 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 12O⁰C, then 10.8 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 22O⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid. EXAMPLE 5

Seventy five weight percent of a charge of 6724 pounds of heated liquid epoxy resin and 3482 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 12O⁰C, then 16.5 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 22O⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid.

EXAMPLE 6

Seventy five weight percent of a charge of 6917 pounds of heated liquid epoxy resin and 3504 pounds of melted bisphenol A are added to a batch reactor having a rotating impeller, wherein when the rotating impeller is from five inches to fourteen inches below the level of the mixture of liquid epoxy resin and bisphenol A which mixture has a temperature of 125⁰C, then 10.5 pounds of ethyl triphenylphosphonium acetate dissolved in methanol is added at full impeller power. Then the remainder of the heated liquid epoxy resin and melted bisphenol A are added to the reactor. The temperature of the mixture in the reactor increases to 225⁰C because the reaction between the liquid epoxy resin and the bisphenol A to produce the converted epoxy resin is exothermic. The converted epoxy resin is flowed from the reactor to a flaker where the converted epoxy resin is cooled and packaged as a flaked solid.

It should be readily apparent that although the present invention has been described above in relation with its preferred embodiments, it should be understood that the present invention is not limited thereby but is intended to cover all alternatives, modifications and equivalents that are included within the scope of the present invention as defined by the following claims.

Claims

WHAT IS CLAIMED IS:

1. A process for producing a converted epoxy resin, comprising the steps of:

(a) heating a liquid epoxy resin to produce a heated liquid epoxy resin; (b) heating an aromatic phenol to produce a heated aromatic phenol;

(c) mixing the heated liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a mixture of liquid epoxy resin and aromatic phenol having a temperature in the range of from about 11O⁰C to about 14O⁰C; and (d) mixing (i) a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with (ii) the mixture of liquid epoxy resin and aromatic phenol to increase the rate of reaction of the aromatic phenol with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with the mixture of liquid epoxy resin and aromatic phenol being greater than about 0.95 in less than about 20 seconds.

2. A process for producing a converted epoxy resin, comprising the steps of: (a) heating a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with liquid epoxy resin to produce a heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin;

(b) heating an aromatic phenol to produce heated aromatic phenol; and (c) mixing the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the heated mixture of liquid epoxy resin and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated aromatic phenol being greater than about 0.95 in less than about 20 seconds.

3. A process for producing a converted epoxy resin, comprising the steps of:

(a) heating a mixture of a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin with an aromatic phenol to produce a heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin; (b) heating liquid epoxy resin to produce heated liquid epoxy resin; and

(c) mixing the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin and the heated liquid epoxy resin essentially without the addition or deletion of heat energy to produce a reactive mixture having an initial temperature in the range of from about 11O⁰C to about 14O⁰C so that the aromatic phenol reacts with the liquid epoxy resin to produce the converted epoxy resin; wherein the uniformity of composition of the mixing of the heated mixture of aromatic phenol and a material that increases the rate of reaction between aromatic phenol and the heated liquid epoxy resin being greater than about 0.95 in less than about 20 seconds.

4. The process of Claim 1, wherein steps (c) and (d) are performed in a batch reactor.

5. The process of Claim 1, wherein steps (c) and (d) are performed in a continuous reactor.

6. The process of Claiml, wherein step (d) is performed in a batch reactor having a rotating impeller wherein the rotating impeller is from about five inches to about fourteen inches below the level of the mixture of liquid epoxy resin and aromatic phenol.

7. The process of Claim2 or 3, wherein step (c) is performed in a batch reactor.

8. The process of Claim2 or 3, wherein step (c) is performed in a continuous reactor.

9. The process of Claim 2 or 3, wherein step (c) is performed in a batch reactor having a rotating impeller wherein the rotating impeller is from about five inches to about fourteen inches below the level of the mixture of liquid epoxy resin, aromatic phenol and a material that increases the rate of reaction between aromatic phenol and liquid epoxy resin.

10. The process of any of Claims 1-3, wherein the aromatic phenol is a bisphenol.

11. The process of Claim 10, wherein the bisphenol is bisphenol A.