United States Patent (19) (11) 4,284,573 Arnett et al. 45) Aug. 18, 1981 54 PREPARATION OF GLYCIDYL ETHERS OTHER PUBLICATIONS 75 Inventors: John F. Arnett, Newton; George A. Chemical Abstracts, vol. 87 (1977) 22359X. Doorakian, Bedford, both of Mass. Primary Examiner-Norma S. Milestone 73) Assignee: The Dow Chemical Company, Attorney, Agent, or Firm-Michael L. Glenn Midland, Mich. 57 ABSTRACT 21 Appl. No.: 80,769 A process for producing glycidyl ethers of phenols is described which comprises the steps of: (22 Filed: Oct. 1, 1979 (1) reacting by contacting, in liquid phase, a phenol with excess epichlorohydrin in the presence of a catalytic 5ll Int. Cl...... CO7D 301/28 amount of tetrahydrocarbyl phosphonium bicarbon 52 U.S. Cl...... 260/348.15; 260/348.19 ate salt, to thereby produce a coupled reaction prod 58) Field of Search ...... 260/348.15, 348.18, uct comprising the corresponding propylene 260/348.19 chlorohydrin ether of said phenol; (2) devolatilizing said coupled reaction product to re 56) References Cited move excess epichlorohydrin and volatile by-pro U.S. PATENT DOCUMENTS ducts; and (3) contacting the devolatilized reaction product from 3,948,855 4/1976 Perry ...... 260/47 EP

Step (2) with aqueous base, thereby converting the 3,992,432 11/1976 Napier et al. ... 260/348.31 . propylenechlorohydrin groups of the coupled reac 3,996,259 12/1976. Lee et al...... 260/348.18 tion product to glycidyl ether groups. FOREIGN PATENT DOCUMENTS This process is particularly useful in preparing low 893.191 7/1970 Canada . molecular weight liquid epoxy resins by the reaction of 2335199 1/1975 Fed. Rep. of Germany ...... 260/348.15 epichlorohydrin with bisphenol A. 2533505 12/1976 Fed. Rep. of Germany ...... 260/348.15 1019565 2/1966 United Kingdom ...... 260/348.15 10 Claims, No Drawings 4,284,573 1 2 teaches that the coupling reaction should be conducted PREPARATION OF GLYCDYL ETHERS at temperatures less than 60° C. At temperatures in excess of 60° C., undesirable polymeric compounds are BACKGROUND OF THE INVENTION formed. 1. Field of the Invention Others have utilized sulfonium salts (e.g., British Pat. This invention pertains to a process of making glyci No. 1,019,565), tertiary amines or quaternary ammo dyl ethers of phenolic compounds by the reaction of nium salts as catalysts for the coupling reaction (e.g., epichlorohydrin with the phenols. More particularly, British Pat. No. 897,744) and still others have utilized this invention pertains to a process for making low phosphonium salts (German AUS. No. 2,335, 199) and molecular weight liquid epoxy resins from the reaction 10 /or phosphoranes (e.g., German Offen. No. 2,533,505). of epichlorohydrin with polyhydric phenols. The latter two German references are the closest prior 2. Prior Art art relative to step one in the instant process in that The prior art is replete with techniques of preparing these references do at least use catalysts containing glycidyl ethers of phenols and particularly for prepar phosphorus. ing glycidyl ethers of polyhydric phenols. 15 The dehydrochlorination step has also been the sub The usual preparation of glycidyl ethers of phenols ject of investigation. Smith (U.S. Pat. No. 3,372,442) involves the reaction of epichlorohydrin with a phenol teaches that the dehydrochlorination is facilitated by in the presence of an alkali metal hydroxide, as repre using an aqueous sodium hydroxide solution which is sented by the following equation: substantially saturated with sodium carbonate. Becker 20 (U.S. Pat. No. 3,980,679) teaches that the dehydrochlo R rination is facilitated by adding solid alkali metal hy O droxide incrementally to the reaction mixture. / N None of the aforementioned references teach that Cl-H2C-HC - CH2 + HO - NaOH there is any advantage in conducting the dehydrochlo 25 rination step in the presence of a quaternary onium salt nor do they indicate what effect, if any, the residual O quaternary onium salts or other catalysts have on the / N reaction product or on this particular step of the overall H2C - CH-CH2-O -- NaCl -- H2O reaction. It is known, however, that amines and quater 30 nary ammonium salts are capable of causing degrada The stoichiometry of the reaction requires one equiva tion of the epoxides. And at least one of the references lent of epichorohydrin and one equivalent of base per specifically teaches that the catalyst for the coupled phenolic hydroxyl group. However, excessive amounts reaction should be removed from the reaction mixture of undesirable by-products are produced if one uses a 35 prior to the dehydrochlorination reaction (British Pat. stoichiometric ratio of reactants. To maximize the yield No. 897,744). The other references are not as explicit in of the glycidyl ether, excess epichlorohydrin and excess their written description but convey the same teaching base have been used to a substantial advantage. One of in that they wash the coupling reaction product with the major problems associated with the use of excess water to remove the catalyst and/or water-soluble by epichlorohydrin has been the recovery of unreacted 40 products, (e.g., sodium chloride and other salts) before epichlorohydrin from the reaction product. the dehydrochlorination step. Still other references A typical multistep method for preparing glycidyl handle the problem by passing the glycidyl ether of the ethers of phenols which results in the production of low phenol through various clays or other materials to ab molecular weight epoxy resins is described in U.S. Pat. sorb the residual catalyst from the reaction product. No. 2,943,095 (Farnham et al.). Farnham et al. con 45 The glycidyl ethers of phenols can be prepared ac ducted the reaction of epichlorohydrin with a polyhyd cording to the above techniques using either batch pro ric phenol in two steps: In the first step, the phenol is cesses or by continuous processes. This is illustrated by reacted with excess epichlorohydrin in the presence of the above references and by German Pat. No. 2,522,745 a base (e.g., lithium chloride, lithium acetate and alkali and German Pat. No. 2,523,696. metal hydroxides) to give a product comprising the 50 propylene chlorohydrin of the phenol. This reaction is SUMMARY OF THE INVENTION generally referred to as the coupling reaction. Farnham A process for producing glycidyl ethers of phenols et al. report that in stage one, the reaction temperature has now been discovered which comprises the steps of: should not exceed 45 C. In step two, the coupled reac (a) introducing a catalytic amount of a tetrahydrocar tion product is dehydrohalogenated with a strong base 55 by phosphonium bicarbonate salt into a liquid phase to form the corresponding glycidyl ether of the phenol. mixture of a phenol with excess epichlorohydrin to This dehydrohalogenation is normally performed in a thereby produce at reactive conditions a coupled reac mixture of liquids comprising a volatile water-soluble 'tion product comprising the corresponding propylene alcohol or ketone and a water-immiscible liquid. Farn chlorohydrin ether of said phenol; and ham et al. recover excess epichlorohydrin by distillation (b) contacting the coupled reaction product in a liq between steps one and two. uid organic solvent with sufficient aqueous base in the Many other patents have issued which also use a presence of a catalytic amount of the tetrahydrocarbyl multistep reaction and which teach that various cata phosphonium bicarbonate salt or its in situ derivative lysts may be used to promote the coupling reaction. salts from step (a) to convert the propylenechlorohy Reinking et al. (U.S. Pat. No. 2,943,096) indicate that 65 drin groups to the corresponding glycidyl ether groups. the coupling step is greatly facilitated by conducting the The glycidyl ethers prepared in the above-described reaction under anhydrous conditions in the presence of manner are advantageous because of their excellent a quaternary ammonium salt catalyst. This reference color and purity. Epoxy resins produced by this process 4,284,573 3 moveover have the advantage of a low total organic chloride content and a narrow molecular weight distri R R R R I bution that corresponds closely to theory. DETAILED DESCRIPTION OF THE HO X OH INVENTION Phosphonium Bicarbonate Salts R R R R

The tetrahydrocarbyl phosphonium bicarbonate salts O wherein each R independently is hydrogen, halogen correspond to the formula I (fluoro, chloro or bromo) or a hydrocarbyl radical and X is oxygen, sulfur, -SO-, -SO2-, bivalent hydro carbon radicals containing up to about 10 carbon atoms, and oxygen-, sulfur- and nitrogen-containing hydrocar R.--R, HCO3G, 15 bon radicals, such as -OR'O-, -OR'OR'O-, -S-R'-S-, -S-R'-S-R-S-, -OSiO-, -OSiOSiO-, wherein R1, R2, R3 and R4 independently are hydro O O carbyl or inertly-substituted hydrocarbyl radicals, hav 20 ing from 1 to about 20 carbon atoms. R1, R2, R3 and R4. are preferably C1 to C12 alkyl groups or phenyl and and -SO2-R'-SO2-radicals wherein R is a bivalent more preferably are C1 to C4 alkyl or phenyl. More hydrocarbon radical. 4,4'-Isopropylidenediphenol (i.e., preferably R1-R3 are each phenyl groups and R4 is an bisphenol A) is the most preferred phenol. n-butyl group. Most preferably R1-R3 are each n-butyl 25 groups and R4 is a methyl group. COUPLING REACTION: STEP (A) Compounds of the formula I are conveniently pre The process for preparing glycidyl ethers of phenols pared by reacting at room temperature a tetrahydrocar consists of two distinct reactions-coupling (Step (a)) and dehydrochlorination (Step (b)). These reactions can byl phosphonium halide dissolved in a lower alkanol 30 be carried out in a batch, semi-continuous or continuous with an ion-exchange resin (quaternary ammonium hy process. droxide type), to thereby produce a solution containing The so-called "coupling reaction' is the reaction the corresponding tetrahydrocarbyl phosphonium hy. between a phenol and epichlorohydrin to produce the droxide salt. Carbon dioxide at a positive pressure is 35 corresponding propylenechlorohydrin ether of the phe then brought into intimate contact with the alkanoic nol, as shown by the equation: solution of the phosphonium hydroxide salt at room temperature so as to produce the tetrahydrocarbyl R phosphonium bicarbonate salt. O 40 / N Illustrative examples of the instant class of catalysts OH + CH-CHCH2Cl catalyst G include those of formula I wherein R1-R4 are each ethyl, n-butyl, hexyl, octyl, phenyl, benzyl, hydroxy R methyl, cyanoethyl, and the like. Other illustrative ex OH amples include those of formula I in which R1-R4 are 45 different. For example, those in which R1 is n-butyl, R2 OCH2CH-CH2Cl is phenyl, R3 is phenyl and R4 is methyl. PHENOLIC REACTANTS wherein R is a univalent organic radical. Preferably, R 50 is hydrogen, alkyl, aryl, (hydroxyar)alkyl, (hydroxyar)- The phenois, wich are used herein, are a known class thiol or bis(hydroxyar)alkyl. This reaction also pro of organic compounds having one or more hydroxyl duces other by-products. The propylenechlorohydrin groups attached to an aromatic mono- or polycyclic ether in turn can react with a second equivalent of epi hydrocarbon nucleus. This class of compounds includes chlorohydrin to produce a minor amount of 1,3- phenol, alpha- and beta-naphthol, o-, m-, or p-chloro 55 dichloropropanol and the glycidyl ether of the phenol. The coupling reaction is carried out in a liquid phase, phenol, alkylated derivatives of phenol (e.g., o-methyl-, normally with mixing. Convenient rates of reaction 3,5-dimethyl-, p-t-butyl- and p-nonylphenol) and other have been observed at a temperature of from about 40 monohydric phenols, as well as polyhydric phenols, to about 200 C., preferably from about 75 to about such as resorcinol, hydroquinone, phloroglucinol, bis(4- 160 C. hydroxyphenyl)-2'-hydroxyphenyl methane (i.e. tris A catalytic amount of the phosphonium bicarbonate phenol),etc. The polyhydric phenols bearing from 2 to salt is introduced into the reaction medium. The term catalytic amount as used in Step (a) refers to an amount 6 hydroxyl groups and having from 6 to about 30 car of the phosphonium bicarbonate salt introduced which bon atoms are particularly useful in the reaction with 65 effects an increase in the rate of the coupling reaction. epichlorohydrin to form epoxy resins useful in coatings. The phosphonium bicarbonate salt desirably effects this Particularly preferred polyhydric phenols are those rate increase, without producing substantial self-polym corresponding to the formula erization of the epichlorohydrin. In this utility, the 4,284,573 5 amount of catalyst introduced can be varied over a wide nation reaction. Caustic treatment of the 1,3-dichloro range. Generally, however, it is used in quantities from propanol maximizes the recovery of epichlorohydrin about 0.001 to about 10 percent by weight, based on the for recycle. However, it is also operable to distill the combined weight of reactants. Preferably, the catalyst is product mixture only after the dehydrochlorination included in amounts of from about 0.05 to about 5 per reaction. cent by weight. It is believed, but not yet proven, that the bicarbonate DEHYDROCHLORINATION REACTION: STEP counterion of the phosphonium salt exchanges to some (B) extent in situ during the coupling and dehydrochlorina The dehydrochlorination reaction or so-called "epox tion reactions with other proton donating species (HA), 10 idation' reaction conducted in the presence of an aque such as the phenol reactant or water and alkanol dilu ous base produces a glycidyl ether from the correspond ents, as shown by the equation: ing propylenechlorohydrin ether of the phenol with the concomitant formation of a stoichiometric amount of a salt of the base. This reaction is carried out with mixing 15 in a liquid water-immiscible organic medium at a tem Therefore, the actual catalyst species may consist of perature less than 175 C., preferably from about 25 to tetrahydrocarbyl phosphonium bicarbonate, hydroxide, about 150 C., with an aqueous base and in the presence alkoxide, phenoxide salts or mixtures thereof. For the of a catalytic amount of the phosphonium bicarbonate sake of brevity, these possible catalyst species are salt or its in situ derivative salts from step (a). For rea termed tetrahydrocarbyl phosphonium bicarbonate and sons of convenience, it is preferred that the in situ deriv its in situ derivative salts. ative salts of the hosphonium bicarbonate from step (a) The ratio of the reactants is desirably at least about be employed in step (b). However, it is also operable to 1.5, preferably greater than about 2.5, equivalents of add a catalytic amount of a tetrahydrocarbyl phospho epichlorohydrin per phenolic hydroxyl group. To facil nium bicarbonate salt directly to the reactants. itate removal of excess epichlorohydrin (i.e., that epi 25 The dehydrochlorination reaction medium includes chlorohydrin in excess of a stoichiometric amount) and two phases-a substantially water-immiscible organic minimize by-products, the ratio of reactants is desirably phase and an aqueous phase having a basic pH. The less than about 20, preferably less than about 10, equiva organic phase can operably consist essentially of the lents of epichlorohydrin per phenolic hydroxyl group. equilibrium reaction mixture resulting from the cou The manner in which the reactants are brought together 30 pling reaction. Alternatively, the organic phase can is not critical, so long as the aforementioned ratios are effected. operably be the devolatized coupling reaction mixture. The reactants at operable temperatures and ratios are However, preferably the coupled reaction medium is generally present in the liquid phase, hence no other first distilled to remove the more volatile organic chlo solvent or dispersive medium is needed. However, sol 35 rine compounds and then a sufficient quantity of an vents inert in the reaction can be employed as desired to organic hydrocarbon solvent is added to the devola improve heat transfer, dispersion of the reactants, to tized or substantially devolatized coupled reaction facilitate the introduction of the individual reactants or product to dissolve said product. The organic hydro catalyst into the reaction medium, or to achieve other carbon solvent should be inert in the dehydrochlorina purposes desired by the skilled artisan. It is preferable, 40 tion reaction and should, of course, dissolve the coupled but not essential that an excess of epichlorohydrin be reaction product. Representative compounds which are employed as the solvent. generally suitable as solvents include lower chlorinated Generally, it is desirable for reasons of economy to alkanes, such as methylene chloride and the like, and convert all or substantially all of the phenol reactant to aromatic hydrocarbons, such as toluene, and the like. the corresponding propylenechlorohydrin ether. The 45 The aqueous base acts as an acceptor for the hydro reaction time required to attain an equilibrium state in gen chloride produced by the dehydrochlorination re which substantially all (i.e., greater than about 98 mole action. Suitable hydrochloric acid acceptors include percent) of the phenol is converted to the coupled reac both inorganic and organic bases, but the water-soluble tion product depends upon the reaction temperature, inorganic hydroxides are preferred due to cost, ease of the particular phenol reactant and other factors. Typi 50 handling, their inactivation of the phosphonium salt cally, the reaction time to attain the equilibrium state for catalyst after a period of contact, etc. Representative reaction temperatures from 75 C. to 160° C. is between bases include sodium and potassium hydroxides, sodium 0.25 and 6 hours. and potassium carbonates, sodium and potassium phos At equilibrium, the reaction medium contains in addi phates, triethylamine, pyridine, and the like. Sodium tion to the propylenechlorohydrin ether of the phenol, 55 hydroxide is the preferred base because of its commer various phosphonium salts, epichlorohydrin, minor cial availability and relative cost. amounts of the glycidyl ether of the phenol, 1,3- The term catalytic amount as used in Step (b) refers dichloropropanol and other by-products. Because hy to an amount of the phosphonium bicarbonate salt or its drolyzable chlorine greater than 400 parts per million in situ derivative salts which effects an increase in the by weight or total organic chlorine content greater than rate of dehydrochlorination. The identity of the hydro about 0.6 weight percent can have a deleterious effect carbyl substituents borne by phosphorus in the tetrahy on the properties of an epoxy resin product, it is impor drocarbyl phosphonium bicarbonate or its in situ deriv tant that most of the organic chlorine be removed from ative salts is relevant in determining the catalytic activ the glycidyl ether products to be employed as epoxy ity of the phosphonium salt in the dehydrochlorination resins. It is desirable, but not essential to remove the 65 reaction. It has been discovered that 1,3-dichloropropanol and excess epichlorohydrin by (n-C4H9)3P6CH3. HCO3e, (C6H5)3P69-n-(-C4H9) vacuum distillation of the equilibrium mixture resulting HCO3(B and to a lesser extent (C6H5)3P6CH3 HCO3e from the coupling reaction prior to the dehydrochlori (wherein C6H5 is phenyl at each occurrence) and their 4,284,573 7 8 in situ derivatives from step (a) all act as phase-transfer polyglycidyl ethers of polyhydric phenols, such as the catalysts which enhance the rate of the dehydrochlori diglycidyl ether of bisphenol A, and the di- or triglyci nation reaction. The skilled artisan can readily deter dyl ether of phloroglucinol are useful as epoxy resins. mine as necessary whether other specific tetrahydrocar These epoxy resins can be reacted with polyhydric byl phosphonium bicarbonate or its in situ derivative phenols or polycarboxylic acids in the manner de salts not explicitly named herein possess the requisite scribed in U.S. Pat. Nos. 3,477,990 and 4,048,141 to catalytic activity in the disclosed process by preparing prepare a variety of useful compositions. epoxy resins as disclosed in the examples. The quantity The following examples further illustrate the inven of catalyst employed in the dehydrochlorination reac tion. All parts and percentages are by weight unless tion can vary over a wide range. Conveniently, the 10 quantity of catalyst is substantially the same as that otherwise specified. employed in the preceding coupling reaction and is EXAMPLE 1. simply carried over in the reaction medium employed in this coupling reaction. Preparation of (n-C4H9)3PépcH3 HCO39 The phosphonium salt during contact with the aque 15 A solution of 100 grams of tri(n-butyl)methyl phos ous base in the dehydrochlorination reaction reacts to phonium bromide salt in 40 grams of methanol is perco produce the corresponding phosphine oxide in the fol lated through a tightly packed column of 509 grams of lowing manner: a quaternary ammonium-type, styrenedivinylbenzene anion exchange resin (sold under the tradename Do 20 wex (R) SBR) bearing 3.5 milliequivalents per gram of The fact that the phosphine oxide is not effective as a exchangeable hydroxide groups. The methanol solution catalyst in the dehydrochlorination reaction is both an is found by conventionl methods of analysis to contain advantage and disadvantage. Advantageously, because 17 percent of tri(n-butyl)methyl phosphonium hydrox the presence of the deactivated catalyst residue in the ide salt and containing only 0.05 percent bromine. glycidyl ether product does not create stability or end 25 To the methanol solution of use problems, it is unnecessary to remove the deacti vated catalyst from the product. However, the effec tiveness of the particular phosphonium salt in catalyz ing the biphasic dehydrochlorination will depend upon 6.07 grams of wateris added with stirring at room temper the relative rates of dehydrochlorination and degrada 30 ature. Gaseous carbon dioxide is then sparged through tion of the catalyst to the phosphine oxide. Therefore, the solution until 14.85 grams has been absorbed. After with some tetrahydrocarbyl phosphonium salt catalyst stirring the solution for one hour, the methanol solvent species which degrade relatively rapidly, such as tri(- is then distilled under reduced pressure to yield 92.7 phenyl)methylphosphonium bicarbonate, it is necessary grams of a colorless crystalline solid. Conventional to utilize a relatively larger initial quantity of the phos 35 methods of analysis (infrared spectroscopy, proton and phonium bicarbonate or in situ derivative salt catalyst phosphorus nuclear magnetic resonance spectroscopy) or to introduce catalyst intermittently during the course are utilized to identify the product as tri(n-butyl)methyl of the dehydrochlorination reaction to provide a cata phosphonium bicarbonate salt. The yield of this product lytic amount of the salt to substantial completion of the based on the corresponding bromide is 99.0 mole per reaction. 40 Cent. The time required to effect substantially complete dehydrochlorination of the propylene chlorohydrin of EXAMPLE 2 the phenol depends primarily upon the reaction temper Preparation of Epoxy Resins ature, the character of the particular chlorohydrin and the identity and quantity of the catalyst present. Typi 45 To a reaction vessel equipped with an internal stirrer cally, the reaction time to effect substantially complete and a means for recording temperature is charged 228 epoxidation for reaction temperatures from 25 C. to grams (1.0 mole) of 4,4'-isopropylidenediphenol (bis 150 C. is between 0.2 and 4 hours, the reaction pro phenol A), 1387.5 grams (15.0 moles) of epichlorohy ceeding more rapidly at relatively higher temperatures. drin and 18.5 grams of a 30 percent solution of tri(n- Of course, in those end uses in which it is desirable to 50 butyl)methylphosphonium bicarbonate salt (0.02 moles) first deactivate the catalyst, a longer contact time may in an aqueous, methanol medium. The stirred reaction be desirable. mixture is heated from 20° C. to 150° C. and held at the After the dehydrochlorination reaction is complete latter temperature for 1 hour. The unreacted epichloro the product is conveniently recovered by first separat hydrin and the reaction by-product 1,3-dichloro ing the organic layer from the aqueous phase and then 55 propanol is then distilled from the reaction mixture at washing the organic phase with water until a neutral reduced pressure. wash substantially free of ionic chloride is obtained. The distilled reaction product is dissolved at 20°C. in The washed organic phase is then distilled at reduced an equal weight of methylene chloride and combined pressure to remove solvent and any residual volatile with 489 grams of an 18 percent solution of aqueous organic chloride compounds from the glycidyl ether of 60 sodium hydroxide. The stirred biphasic mixture is the phenol. heated to 75 C. and maintained at this temperature for 0.5 hour. The organic and aqueous phases are separated Reaction Products and the organic layer is washed with water until the The glycidyl ether of phenols here produced are aqueous wash has a neutral pH. The methylene chloride generally known compounds in industry. These glyci 65 is then removed by distillation to yield 328.8 grams of dyl ethers of phenols are generally useful as reactive an off-white (Gardner 2) viscous liquid. The yield of intermediates in the preparation of coatings, adhesives, this product based on the bisphenol A is 96.7 mole per reinforced plastics, moldings, etc. In particular, the cent. 4,284,573 10 The observed epoxy content of the resin product determined by conventional wet analysis technique is EXAMPLE 5 23.6 percent; almost identical to the theoretical value of A precatalyzed epichlorohydrin mixture is prepared 24 percent obtained if all the product is present as the by combining 740 grams of epichlorohydrin with 26 diglycidyl ether of bisphenol A. The epoxy equivalent grams of a 30 weight percent solution of tri(n-butyl)- weight of the product is 182 and the viscosity is 8500 methyl phosphonium bicarbonate salt in an aqueous, centipoise at 25" C. The resin product contains 0.26 methanol solvent. In a manner otherwise similar to percent total chlorine with less than 37 parts per million Example 2, 76.6 grams of the precatalyzed mixture (0.8 (ppm) hydrolyzable chlorine as determined by titration mole of epichorlohydrin) is added to 22.8 grams (0.1 with silver nitrate in the conventional manner. The 10 mole) of (p,p'bisphenol A) at 20° C. The stirred reaction mixture is heated to 105 C. and held at the latter tem resin also contains less than 50 ppm phenolic hydroxyl perature for 4 hours. The mixture is devolatilized by groups. A linear epoxy resin was thus provided having distillation at reduced pressure and then dissolved in low viscosity, very low color and low residual phenol methylene chloride. ic-hydroxyl and chloride contents. 15 The dehydrochlorination reaction and product re EXAMPLE 3 covery is performed in the manner described in Exam ple 2 to yield 33.58 grams of almost colorless (Gardner In a manner similar to that described in Example 2 2) product. The yield of this product based on the bis (except for the reaction times and temperatures and the phenol A is 98.8 mole percent. The observed epoxide use of an epichlorohydrin solvent in the epoxidation 20 content and epoxy equivalent weight are 23.02 percent reaction), a stirred mixture of 22.8 grams (0.1 mole) of and 187, respectively. The product contains a total pp'-bisphenol A, 74 grams (0.8 mole) of epichlorohy chlorine content of 0.28 percent with 65 ppm hydrolyz drin and 1.85grams of an aqueous, methanol solution of able chlorine and 50 ppm phenolic hydroxyl groups. 30 percent tri(n-butyl)methylphosphonium bicarbonate The viscosity of the freshly-prepared resin is 10,500 salt is heated from 20° C. to 105 C. and maintained at 25 centipoise at 25 C. and increases to only 10,625 centi the latter temperature for about 4 hours. At 20 C., 48.8 poise at 25 C. after storage for 2 weeks at 25 C., which grams of an 18 percent aqueous solution of sodium indicates excellent room temperature stability. hydroxide is added to the reaction mixture and then the In order to demonstrate the high temperature stabil stirred mixture is heated to 45 C. for 3 hours. The ity of the instant resin product, 5.29 grams of epoxy organic phase of the reaction mixture is separated and 30 resin grade bisphenol A (97 percent of p,p'-bisphenol A washed with water until the aqueous wash has a neutral and 3 percent o,p'-bisphenol A) is added to 10 grams of pH. The excess epichlorohydrin and other volatile com liquid resin to produce a mixture having an observed ponents are then distilled from the product to yield epoxy content of 14.92 percent. After heating the mix 30.01 grams of an off-white (Gardner 2) viscous liquid ture to 160° C. for 3 hours, the epoxy content of the product. The yield of this product based on the bisphe 35 mixture is determined to be 12.06 percent. nol A is 88.4 mole percent. The observed epoxy content COMPARATIVE EXPERIMENT of the resin product is 21.58 percent. In a manner otherwise identical to Example 4, 0.002 EXAMPLE 4 mole of a prior art coupling catalyst, benzyltrime 40 thylammonium chloride (BTMAC), is utilized instead In a manner similar to that described in Example 2, a of the tri(n-butyl)methyl phosphonium bicarbonate salt stirred mixture of 22.8 grams (0.1 mole) of industrial to catalyze the preparation of the corresponding diglyc grade bisphenol A (90-98 percent p,p'-bisphenol A and idyl ether from epichlorohydrin and bisphenol A. The a remaining amount of other isomers), 74 grams (0.8 resulting epoxy resin product is 29.01 grams of a light mole) of epichlorohydrin and 1.85 grams of an aqueous, 45 yellow (Gardner 6), viscous liquid for a yield of 90 mole methanol solution of 30 percent tri(n-butyl)methyl percent based on bisphenol A. The observed epoxy phosphonium bicarbonate salt (0.002 mole) is heated content and epoxy equivalent weight of the product are from 20 C. to 105 C. and maintained at the latter tem 19.98 percent and 215, respectively. The product also perature for about 4 hours. The reaction by-product contains 1.23 percent of total chlorine and greater than 1,3-dichloropropanol and the unreacted epichlorohy 50 1000 ppm of phenolic hydroxy groups. The viscosity of drin is then distilled from the reaction mixture at re the freshly-prepared resin is 50,135 centipoise at 25 C. duced pressure. and increases to 71,634 centipoise at 25 C. after storage The distilled reaction product is dissolved at 20° C. in for 2 weeks at 25° C. The BTMAC catalyst, unlike the 80 milliliters of toluene and combined with 100 milli catalysts utilized in the instant novel process, causes 55 instability of the resin product. liters of a 12 percent solution of aqueous sodium hy In order to demonstrate the relative thermal instabil droxide. The stirred biphasic mixture is refluxed for 2.5 ity of the BTMAC-prepared product, 3.12 grams of hours and then the organic layer is separated and epoxy resin-grade bisphenol A is added to 6.88 grams of washed with water. Finally, the toluene is removed by product to produce a mixture having an observed epoxy distillation to yield a light yellow (Gardner 3) viscous 60 content of 13.74 percent. After heating the mixture to epoxy resin in 95 mole percent yield based on bisphenol 160 C. for 3 hours, the observed epoxy content is re A. duced to 7.91 percent. The observed epoxy content of the resin product is 22.8 percent and the epoxy equivalent weight is 187. EXAMPLE 6 The viscosity of the resin is 11,500 centipoise at 25 C. 65 In a manner otherwise similar to Example 5, 38.3 and resin is determined by conventional methods of grams of the precatalyzed epichlorohydrin mixture (0.4 analysis to contain a total chlorine content of 0.29 per mole of epichlorohydrin) is added to 15.0 grams (0.1 cent and less than 100 ppm of phenolic hydroxyl. mole) of p-t-butylphenol at 20° C. The mixture is heated 4,284,573 11 12 to 120° C. and held at this temperature for 2 hours. The situ derivative salts to convert the propylene product mixture is then devolatilized and dehydro chlorohydrin groups to glycidyl ether groups. chlorinated as is described in Example 5. The 19.6 2. The process defined by claim 1 wherein step (a) is grams of product remaining after distillation is identi conducted at a temperature of from about 40' to about 200° C. fied by conventional methods of analysis as p-t-butyl 3. The process defined by claim 1 wherein step (a) is phenylglycidyl ether. This represents a 92 percent yield conducted at a temperature of from about 75" to 160° C. based on the corresponding phenol reactant. 4. The process defined by claim 1 wherein in step (b) EXAMPLE 7 said organic solvent is methylene chloride or toluene. 10 5. The process defined by claim 4 further comprising In a manner otherwise identical to Example 6, o-t- washing said organic solution of the glycidyl ether of a butylphenol is employed instead of the para isomer and phenol from step (b) with water so as to effect removal the 120° C. reaction temperature is maintained for 6 of substantially all ionic chloride contaminants. hours. 18.5 Grams of o-t-butylphenylglycidyl ether is 6. The process defined by claim 1 further comprising recovered representing a 90 percent yield based on the 15 distilling the reaction product of step (a) to remove phenol reactant. residual epichlorohydrin and 1,3 -dichloropropanol from the reaction product prior to step (b). EXAMPLE 8 7. The process defined by claim 1 wherein about 1.5 In a manner similar to that described in Example 4, a to about 20 equivalents of epichlorohydrin per phenolic stirred mixture of 14.0 grams (0.048 mole) of trisphenol, 20 hydroxyl group are present in step (a). 50.6 grams of epichlorohydrin and 0.260 gram of tri(n- 8. The process defined by claim 1 wherein the phenol butyl)methyl phosphonium bicarbonate salt in 65.5 per reactant is represented by cent solution of methanol is maintained at 150° C. for 1 hour. The reaction mixture is then cooled to 100° C. and R R distilled at reduced pressure (25 mm of Hg) to remove 25 volatile components. To the undistilled residue is added 40 ml of benzene HO OH and 50 ml of a 12 percent NaOH solution in water. The resulting triphasic mixture is refluxed for 2.5 hours and R R R R then the organic layer is separated and washed with 30 water. Finally, the benzene and other volatiles are re wherein each Rindependently is hydrogen, halogen or moved by distillation at 160° C. under reduced pressure a hydrocarbyl radical and X is oxygen, sulfur to yield the final resin. The epoxy equivalent weight of -SO--SO2-, a bivalent hydrocarbon radical con the resin is 168. taining up to about 10 carbon atoms, -OR'O-, OR 35 "OR"O--S-R'-S--S-R'--OSiO--OSi EXAMPLE 9 OSiO-, To a mixture of 0.4 mole epichlorohydrin and 0.1 mole p-t-butylphenol is added 0.004 mole of n-butyl O triphenyl phosphonium bicarbonate at 25° C. This 40 I stirred mixture is heated to 120° C. and held at this temperature for 2 hours. The product mixture is then or-SO2-R'-SO2-radical, where R' is a bivalent devolatilized and dehydrochlorinated as described in hydrocarbon radical. Example 5. The 20.1 grams of product remaining after 9. The process defined by claim 1 wherein distillation is identified by conventional methods of 45 (a) epichlorohydrin is reacted with bisphenol A in a analysis as p-t-butylphenylglycidyl ether. This repre ratio of about 1.5 to about 20 equivalent of a epi sents a 94.3 percent isolated yield based on the corre chlorohydrin per phenolic hydroxyl group at a temperature of from about 140° C. to about 175 C. sponding phenol reactant. to produce a coupled reaction product; and What is claimed is: 50 (b) the coupled reaction product is contacted in a 1. A method of producing a glycidyl ether of a phenol methylene chloride solution with sufficient sodium comprising the steps of: hydroxide in the presence of a catalytic amount of (a) introducing a catalytic amount of a tri-n-butyl)- a tri(n-butyl)methyl phosphonium bicarbonate salt, methyl phosphonium bicarbonate salt into a liquid so as to produce the diglycidyl ether of bisphenol phase mixture of a phenol with excess epichlorohy 55 A. drin to thereby produce at reactive conditions a 10. A process comprising introducing a catalytic coupled reaction product comprising the corre amount of a tri(n-butyl)methyl phosphonium bicarbon sponding propylenechlorohydrin ether of said phe ate salt into a liquid phase medium containing a nol; and propylenechlorohydrin ether of a phenol in the pres (b) contacting the coupled reaction product in a liq 60 ence of sufficient aqueous base, so as to convert the uid organic solvent with sufficient aqueous base in propylenechlorohydrin groups to glycidyl ether the presence of a catalytic amount of the tri(n- groups. butyl)methyl phosphonium bicarbonate or its in 2: k . . k. 65 UNITED STATES PATENT AND TRADEMARKoFFICE CERTIFICATE OF CORRECTION

DATED August 18, 1981 INVENTOR(S) : John F. Arnett and George A. Doorakian It is Certified that error appears in the above-identified patent and that said Letters Patent is hereby Corrected as shown below: Column 6, line 67, "HCO" should be -- HCo. -- Column 11 line 53, "tri-n-butyl)-" should be -- tri (n-butyl)- - -; Column 12, line 7, after "to" insert -- about --; Column 12, line 36, after "-S-R'-," insert - - -S-R'-S-R'-S-, --; Column l2, line 41, "where" should be a- wherein or Column 12, line 46, "equivalent" should be plural. eigned and sealed this Twenty-seventh Day of April 1982

GERALD . MOSSINGHOFF Attesting Officer Commissioner of Patents and Trademarks