Preparation of advanced epoxy resins and dihydric phenols in the presence of phosphonium compounds

Abstract: Advanced epoxy resins are prepared from glycidyl ethers of bisphenols or biphenols in the presence of cycloalkyl triphenyl phosphonium catalysts.

Description: The present invention concerns the preparation of high molecular weight epoxy resins by reacting low molecular weight epoxy resins with a dihydric phenol in the presence of certain phosphonium compounds. High molecular weight epoxy resins have been prepared by reacting low molecular weight epoxy resins with dihydric phenols in the presence of phosphonium catalysts such as disclosed in US-A-3,477,990 and 3,948,855. While the phosphonium halide and carboxylate complex catalysts disclosed therein do indeed prepare high molecular weight epoxy resins, it would be desirable to be able to prepare high molecular weight resins with certain improved properties in the process employed to produce them and/or in the products so produced. US-A- 4 122 067 discloses the use of phosphonium catalysts with aliphatic, cycloaliphatic or aromatic hydrocarbon radicals, such as triphenylmethyl-phosphonium iodine. In the production of high molecular weight resins, it is often desirable to employ temperatures in excess of 200°C so that the viscous products can be physically agitated or transferred. However, at these temperatures, the conventional phosphonium catalysts are deactivated prematurely, resulting in incomplete reaction and products containing high levels of unreacted phenolic hydroxyl groups and low equivalent weight or low molecular weight products are produced. It would be desirable to employ a process using a catalyst which is more active at elevated temperatures so that for the same ratio of reactants employed, higher equivalent weight or molecular weight epoxy resins can be produced which contain lower amounts of residual or unreacted phenolic hydroxyl groups. Also, one convenient method for packaging epoxy resins which are to be advanced into higher molecular weight epoxy resins is to mix the low molecular weight epoxy resin with the catalyst; however, with the conventional phosphonium catalysts, upon prolonged storage at elevated temperatures, the catalyst tends to become deactivated or at a minimum lose its activity. It would also be desirable to employ a catalyst in these precatalyzed packages or mixtures which does not become deactivated during storage at elevated temperatures or at a minimum does not lose as much of its activity at elevated temperatures. One aspect of the present invention pertains to a precatalyzed epoxy resin composition which is essentially free of epoxy resin curing agents and which contains (A) at least one relatively low molecular weight epoxy resin having an average of more than one but not more than 2 vicinal epoxy groups per molecule; and (B) at least one phosphonium catalyst; characterized in that, a cycloalkyl triphenyl phosphonium compound is employed as the phosphonium catalyst. Another aspect of the present invention pertains to a process for the preparation of advanced epoxy resins by reacting (A) at least one epoxy resin having an average of more than one but not more than about 2 vicinal epoxy groups per molecule; with (B) at least one compound having 2 aromatic hydroxyl groups per molecule; in the presence of (C) a phosphonium catalyst; characterized in that a cycloalkyl triphenyl phosphonium compound is employed as the phosphonium catalyst. In the precatalyzed epoxy resin compositions of the present invention, the phosphonium compound is employed in an amount suitably from 0.0001 to 10, more suitably from 0.05 to 1, most suitably from 0.1 to 0.5 percent by weight based upon the weight of the epoxy resin. Relatively high molecular weight epoxy resins are prepared by reacting a relatively low molecular weight epoxy resin and a phenolic hydroxyl-containing compound in the presence of the phosphonium catalyst at temperatures suitably from 50°C to 280°C, more suitably from 100°C to 240°C, most suitably from 120°C to 220°C. Atmospheric, subatmospheric or superatmospheric pressures can be employed. However, the reaction is particularly suitably conducted at pressures of from 6.9 kPa (1 psig) to 1034.1 kPa (150 psig), more suitably from 34.5 kPa (5 psig) to 551.5 kPa (80 psig,) most suitably from 68.9 kPa (10 psig) to 137.9 kPa (20 psig). The reaction is conducted for a time to complete the reaction; however, times suitably from 0.5 to 20, more suitably from 1 to 8, most suitably from 2 to 5 hours can be employed. The epoxy resin and the compound having 2 phenolic hydroxyl groups per molecule are employed in amounts which provide a ratio of phenolic hydroxyl groups to epoxide groups suitably from 0.01:1 to 2:1, more suitably from 0.2:1 to 1.5:1, most suitably from 0.5:1 to 1:1. The phosphonium catalyst is employed in catalytically sufficient amounts to catalyze the reaction between the epoxide group and the phenolic hydroxide group. Usually, these amounts are suitably from 0.0001 to 0.1, more suitably from 0.0005 to 0.05, most suitably from 0.001 to 0.005 moles of catalyst per mole of the relatively low molecular weight epoxy resin. Any phosphonium compound which has three phenyl groups attached to the phosphorus atom and one cycloalkyl group attached to the phosphorus atom can be employed herein. It does not matter what the anion portion of the phosphonium compound happens to be. Particularly suitable anions include, for example, the halides such as, for example, chloride, bromide or iodide; the carboxylates such as, for example, formate, acetate, oxalate, trifluoroacetate, carboxylate·carboxylic acid complexes such as, for example, acetate·acetic acid complex; conjugate bases of inorganic acids such as, for example, bicarbonate, tetrafluoroborate or biphosphate; and conjugate bases of phenols, such as, for example, phenate or an anion derived from a bisphenol or biphenol such as, for example, bisphenol A or bisphenol F, and combinations thereof. The cycloalkyl triphenyl phosphonium catalysts which can be employed herein include, for example, those represented by the following formula I wherein Q is a cycloalkyl or alkyl or halo substituted cycloalkyl group having suitably from 3 to 8, more suitably from 4 to 7, most suitably from 5 to 6 carbon atoms in the cycloalkyl ring; each R is independently hydrogen, a halogen, or a hydrocarbyl group having suitably from 1 to 12, more suitably from 1 to 6, most suitably from 1 to 3, carbon atoms; Z is an anion such as, for example, halide such as, for example, chloride, bromide or iodide; carboxylate such as, for example, formate, acetate, oxalate, trifluoroacetate, carboxylate·carboxylic acid complex such as, for example, acetate·acetic acid complex; conjugate base of an inorganic acid such as, for example, bicarbonate, tetrafluoroborate or biphosphate and a conjugate base of a phenol, such as, for example, phenate or an anion derived from a bisphenol or biphenol such as, for example, bisphenol A or bisphenol F, and combinations thereof. The term hydrocarbyl as employed herein means any aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic or cycloaliphatic, or aliphatic or cycloaliphatic substituted aromatic groups. Likewise, the term hydrocarbyloxy means a hydrocarbyl group having an oxygen linkage between it and the object to which it is attached. Particularly suitable catalysts include, for example, cyclopropyl triphenyl phosphonium iodide, cyclopropyl triphenyl phosphonium bromide, cyclopropyl triphenyl phosphonium chloride, cyclopropyl triphenyl phosphonium acetate, cyclopropyl triphenyl phosphonium acetate·acetic acid complex, cyclopropyl triphenyl phosphonium phosphate, cyclopropyl triphenyl phosphonium heptanoate, cyclopropyl triphenyl phosphonium oxalate, cyclobutyl triphenyl phosphonium iodide, cyclobutyl triphenyl phosphonium bromide, cyclobutyl triphenyl phosphonium chloride, cyclobutyl triphenyl phosphonium acetate, cyclobutyl triphenyl phosphonium acetate·acetic acid complex, cyclobutyl triphenyl phosphonium phosphate, cyclobutyl triphenyl phosphonium heptanoate, cyclobutyl triphenyl phosphonium oxalate, cyclopentyl triphenyl phosphonium iodide, cyclopentyl triphenyl phosphonium bromide, cyclopentyl triphenyl phosphonium chloride, cyclopentyl triphenyl phosphonium acetate, cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclopentyl triphenyl phosphonium phosphate, cyclopentyl triphenyl phosphonium heptanoate, cyclopentyl triphenyl phosphonium oxalate, cyclopropyl triphenyl phosphonium iodide, cyclopropyl triphenyl phosphonium bromide, cyclopropyl triphenyl phosphonium chloride, cyclopropyl triphenyl phosphonium acetate, cyclopropyl triphenyl phosphonium acetate·acetic acid complex, cyclopropyl triphenyl phosphonium phosphate, cyclopropyl triphenyl phosphonium heptanoate, cyclopropyl triphenyl phosphonium oxalate, cyclohexyl triphenyl phosphonium iodide, cyclohexyl triphenyl phosphonium bromide, cyclohexyl triphenyl phosphonium chloride, cyclohexyl triphenyl phosphonium acetate, cyclohexyl triphenyl phosphonium acetate·acetic acid complex, cyclohexyl triphenyl phosphonium phosphate, cyclohexyl triphenyl phosphonium oxalate, cycloheptyl triphenyl phosphonium iodide, cycloheptyl triphenyl phosphonium bromide, cycloheptyl triphenyl phosphonium chloride, cycloheptyl triphenyl phosphonium acetate, cycloheptyl triphenyl phosphonium acetate·acetic acid complex, cycloheptyl triphenyl phosphonium phosphate, cycloheptyl triphenyl phosphonium heptanoate, cycloheptyl triphenyl phosphonium oxalate, cyclooctyl triphenyl phosphonium iodide, cyclooctyl triphenyl phosphonium bromide, cyclooctyl triphenyl phosphonium chloride, cyclooctyl triphenyl phosphonium acetate, cyclooctyl triphenyl phosphonium acetate·acetic acid complex, cyclooctyl triphenyl phosphonium phosphate, cyclooctyl triphenyl phosphonium heptanoate, cyclooctyl triphenyl phosphonium oxalate, and combinations thereof. The catalysts can be readily prepared by reacting triphenyl or substituted triphenyl phosphines with cycloalkylhalides. The catalysts are commercially available and general procedures and references for their preparation are given in Organo Phosphorous Compounds , by G. M. Kosolapoff, John Wiley & Sons, 1958 and in US-A- 3,341,580. Particularly suitable cycloalkyl halides which can be employed include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl chlorides, bromides, and iodides. These catalysts are believed to be particularly suitable for preparing advanced epoxy resins by the extruder process disclosed in US-A- 4,612,156. Suitable epoxy resins which can be employed herein in the precatalyzed compositions and in the preparation of the advanced epoxy resins include, for example, the relatively low molecular weight epoxy resins represented by the following formulas II or III wherein each A is independently a divalent hydrocarbyl or substituted hydrocarbyl group having suitably from 1 to 12, more suitably from 1 to 6, most suitably from 1 to 3, carbon atoms; each R′ is independently hydrogen or an alkyl group having from 1 to 4 carbon atoms; each X is independently hydrogen or a hydrocarbyl or substituted hydrocarbyl or hydrocarbyloxy or substituted hydrocarbyloxy group having suitably from 1 to 12, more suitably from 1 to 6, most suitably from 1 to 3, carbon atoms or a halogen atom, particularly chlorine or bromine; each n independently has a value of zero or 1; and n′ has an average value from zero to 0.5, particularly from 0.035 to 0.1. Particularly suitable relatively low molecular weight epoxy resins which can be employed herein include, for example, the diglycidyl ethers of such dihydric phenolic compounds as resorcinol, catechol, hydroquinone, biphenol, bisphenol A, bisphenol F, bisphenol K, bisphenol S, and combinations thereof. Suitable compounds having 2 phenolic hydroxyl groups per molecule which can be employed herein include, for example, those represented by the following formulas IV or V wherein A, X and n are as defined above. Particularly suitable compounds having 2 phenolic hydroxyl groups per molecule include, for example, resorcinol, catechol, hydroquinone, biphenol, bisphenol A, bisphenol F, bisphenol K, bisphenol S, and combinations thereof. The resultant advanced high molecular weight epoxy resins which are produced by the process of the present invention can be represented by the above described formulas II and III wherein A, R′,X and n are as previously defined and n′ has an average value suitably from 2 to 40 and above, more suitably from 2.5 to 31, most suitably from 3 to 25. If desired, the reaction can be conducted in the presence of such solvents as ketones, alcohols, hydrocarbons, halogenated aliphatic compounds, glycol ethers, amides, sulfoxides, and combinations thereof. Particularly suitable solvents include, for example, acetone, methyl ethyl ketone, xylene, toluene, ethanol, isopropanol, ethylene dichloride, propylene glycol methyl ether, ethylene glycol n-butyl ether, ethylene glycol ethyl ether, dimethylformamide, dimethylsulfoxide, and combinations thereof. The solvents, when employed, are usually employed in amounts suitably from 0.5 to 90, more suitably from 1 to 80, most suitably from 3 to 50, percent by weight based upon the total weight of the nonvolatile components. The high molecular weight epoxy resins prepared by the process of the present invention can be employed in the preparation of coating formulations, casting formulations, laminating varnishes, encapsulation formulations, and the like. The following examples are illustrative of the invention. EXAMPLE 1 Into a 1 liter, 5-necked glass reactor equipped with a mechanical stirrer, a thermometer connected to a temperature controller and a heating mantel, was charged 395.9 g (2.191 equiv.) of a diglycidyl ether of bisphenol A having an epoxide equivalent weight (EEW) of 180.7. After purging the reactor with nitrogen and warming the resin to 80°C, 204.1 g (1.790 equiv.) of bisphenol A was added and the contents mixed for 15 minutes at 80°C. Then 0.96 g of 24.2 weight percent of cyclopentyl triphenyl phosphonium bromide, cyclo C₅ TPP Br, (0.56 milliequivalent or millimole) in methanol was added to the epoxy resin/bisphenol A slurry and the temperature was gradually increased to 150°C over a period of 45 minutes. At this time, the heating was turned off and an exotherm was allowed to take place at 190°C. During this time, air cooling was used to control the exotherm temperature to less than 200°C. The cook temperature was maintained at 190°C for 4 hours while samples were taken for product analyses. After reacting for 4 hours, the resin was poured out and flaked on aluminum foil. The product analyses and catalyst activity are reported in Tables I and II, respectively. EXAMPLE 2 The procedure of Example 1 was followed except that 1.01 g (0.56 milliequivalent or millimole) of a 22.32 weight percent methanolic solution of cyclohexyl triphenyl phosphonium bromide, cyclo C₆ TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. EXAMPLE 3 The procedure of Example 1 was followed except that 0.46 g (0.56 milliequivalent or millimole) of a 55.51 weight percent methanolic solution of cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclo C₅ TPP Ac·AcA, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. EXAMPLE 4 The procedure of Example 1 was followed except that 0.96 g (0.56 milliequivalent or millimole) of a 23.45 weight percent methanolic solution of cyclopropyl triphenyl phosphonium bromide, cyclo C₃ TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. EXAMPLE 5 The procedure of Example 1 was followed except that 0.92 g (0.56 milliequivalent or millimole) of a 26.78 weight percent methanolic solution of cycloheptyl triphenyl phosphonium bromide, cyclo C₇ TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT A The procedure of Example 1 was followed except that 0.7 g (0.56 milliequivalent or millimole) of a 29.86 weight percent methanolic solution of ethyl triphenyl phosphonium bromide, ethyl TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT B The procedure of Example 1 was followed except that 0.83 g (0.56 milliequivalent or millimole) of a 28.35 weight percent methanolic solution of ethyl triphenyl phosphonium iodide, ethyl TPP I, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT C The procedure of Example 1 was followed except that 0.33 g (0.56 milliequivalent or millimole) of a 70 weight percent methanolic solution of ethyl triphenyl phosphonium acetate·acetic acid complex, ethyl TPP Ac·AcA was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT D The procedure of Example 1 was followed except that 0.7 g (0.56 milliequivalent or millimole) of a 28.87 weight percent methanolic solution of methyl triphenyl phosphonium bromide, methyl TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT E The procedure of Example 1 was followed except that 0.78 g (0.56 milliequivalent or millimole) of a 28.96 weight percent methanolic solution of butyl triphenyl phosphonium bromide, butyl TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT F The procedure of Example 1 was followed except that 1.04 g (0.56 milliequivalent or millimole) of a 30.65 weight percent methanolic solution of hexadecyl triphenyl phosphonium bromide, hexadecyl TPP Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II. respectively. COMPARATIVE EXPERIMENT G The procedure of Example 1 was followed except that 0.84 g (0.56 milliequivalent or millimole) of a 28.13 weight percent methanolic solution of tetraphenyl phosphonium bromide, tetra phenyl P Br, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. EXAMPLE 6 The procedure of Example 1 was employed except that 350 g (1.937 equiv.) of the diglycidyl ether of bisphenol A having an EEW of 180.7; 203.2 g (1.782 equiv.) of bisphenol A and 1.64 g (0.86 milliequiv. or millimole) of 21.52 weight percent solution of cyclopentyl triphenyl phosphonium bromide, cyclo C₅ TPP Br, in methanol were employed. Heating was applied to raise the temperature gradually to 150°C and the exotherm temperature was 210°C to 215°C. The cook temperature was 215°C and was maintained for 4 hours. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT H The procedure of Example 6 was followed except that 0.5 g (0.86 milliequivalent or millimole) of a 70 weight percent methanolic solution of ethyl triphenyl phosphonium acetate·acetic acid complex, ethyl TPP Ac·AcA, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. COMPARATIVE EXPERIMENT I The procedure of Example 6 was followed except that 1.27 g (0.86 milliequivalent or millimole) of a 28.35 weight percent methanolic solution of ethyl triphenyl phosphonium iodide, ethyl TPP I, was employed as the catalyst. The product analysis and catalyst activity are reported in Tables I and II, respectively. The percent active catalyst was determined by dissolving 0.25 g of resin sample in methylene chloride to a total volume of 25 ml. To a 5 ml aliquot was added 15 ml of methylene chloride and 1 ml of a 0.1% aqueous solution of methyl orange indicator in a 2 oz (59.15 ml) bottle. This mixture was shaken for one minute, then allowed to stand for 5 minutes. A 10 ml aliquot was filtered into a Klett tube, which was placed in a Klett colorimeter. The colorimeter measured the color intensity which was directly proportional to active catalyst (phosphonium cation) levels. Catalyst concentration was then calculated based on the ppm active catalyst per Klett unit. The EEW was determined by potentiometric titration of the epoxide group with hydrogen bromide generated in situ by the reaction of perchloric acid with tetraammonium bromide in acetic acid solution. The Viscosity was determined by means of an I.C.I. cone and plate viscometer at 200°C. The residual phenolic hydroxyl content was determined by a spectroscopic procedure in which the phenolic OH was converted to its phenate salt and the absorbance measured with an ultraviolet spectrophotometer. The molecular weight was determined by gel permeation chromatography using a Waters 150 gel permeation chromatograph, GPC, equipped with two Zorbax PSM 60/100 columns in series. The solvent was tetrahydrofuran and the flow rate was 1 ml/minute. Polystyrene resins were used as calibration standards. EXAMPLE 7 and COMPARATIVE EXPERIMENTS J & K A series of stability tests were conducted on a liquid epoxy resin precatalyzed with various phosphonium catalysts. In each of the Examples and Comparative Experiments, 960 grams of a diglycidyl ether of bisphenol A having a percent epoxide of 23.6% and an epoxide equivalent weight of 182.2 and containing 91 ppm hydrolyzable chloride and 1380 ppm total chloride was diluted with 40 grams of xylene to reduce the viscosity. After the epoxy resin/xylene mixture was thoroughly agitated, the phosphonium catalyst was added in an amount to provide 1000 ppm of catalyst by weight based on the weight of the epoxy resin. The precatalyzed epoxy resin mixture was then agitated using a mechanical mixer and subjected to heat aging in a convection oven controlled at a temperature of 50°C. The catalytic activity of the catalyst remaining after heat aging over a period of time is reported in Table III. Ex. or Comp. Expt. Desig. CATALYST EMPLOYED % ACTIVE CATALYST AT 50°C Type % In Methanol Wt. % cat. soln. used Ohr 24 Hrs. 48 Hrs. J Ethyl TPP Ac·AcA 70 1.43 100 52 40 K Ethyl TPP Phosp. 30 3.33 100 82 68 4 CycloC₅ TPPBr 25 4.00 100 100 100 EXAMPLES 8, 9 & 10 and COMP. EXPERIMENTS L, M, N & O The procedure of Example 7 was employed except that the stability test was conducted at 90°C instead of 50°C. A diglycidyl ether of bisphenol A liquid epoxy resin containing 22.9% epoxide (187.1 EEW), 228 ppm hydrolyzable chloride and 2,650 ppm total chloride was used in these experiments. The results are given in Table IV.

Claims: A precatalyzed epoxy resin composition which is essentially free of epoxy resin curing agents and which contains (A) at least one relatively low molecular weight epoxy resin having an average of more than one but not more than 2 vicinal epoxy groups per molecule; and (B) at least one phosphonium catalyst; characterized in that a cycloalkyl triphenyl phosphonium compound is employed as the phosphonium catalyst. A precatalyzed epoxy resin composition of Claim 1 wherein (a) the phosphonium catalyst, component (B), is employed in an amount of from 0.001 to 10 percent by weight based upon the weight of the epoxy resin, component (A); (b) component (A) is an epoxy resin or mixture of epoxy resins represented by the following formulas II or III wherein each A is independently a divalent hydrocarbyl or substituted hydrocarbyl group having from 1 to 12 carbon atoms; each R′ is independently hydrogen or an alkyl group having from 1 to 4 carbon atoms; each X is independently hydrogen or a hydrocarbyl or substituted hydrocarbyl or hydrocarbyloxy or substituted hydrocarbyloxy group having from 1 to 12 carbon atoms or a halogen atom; each n independently has a value of zero or 1; and n′ has an average value from zero to 0.5; and (c) the phosphonium catalyst, component (B) is represented by the following formula I wherein Q is a cycloalkyl group or an alkyl substituted or halo substituted cycloalkyl group wherein the cycloalkyl ring contains from 3 to 8 carbon atoms; each R is independently hydrogen, a halogen, or a hydrocarbyl group having from 1 to 12 carbon atoms; Z is an anion. A precatalyzed epoxy resin composition of Claim 1 wherein (a) the epoxy resin, component (A), is a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, a diglycidyl ether of bisphenol K, a diglycidyl ether of bisphenol S or a mixture of such glycidyl ethers; and (b) the catalyst, component (B), is cyclopropyl triphenyl phosphonium iodide, cyclopropyl triphenyl phosphonium bromide, cyclopropyl triphenyl phosphonium chloride, cyclopropyl triphenyl phosphonium acetate, cyclopropyl triphenyl phosphonium acetate·acetic acid complex, cyclopropyl triphenyl phosphonium phosphate, cyclopropyl triphenyl phosphonium oxalate, cyclopentyl triphenyl phosphonium iodide, cyclopentyl triphenyl phosphonium bromide, cyclopentyl triphenyl phosphonium chloride, cyclopentyl triphenyl phosphonium acetate, cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclopentyl triphenyl phosphonium phosphate, cyclopentyl triphenyl phosphonium oxalate, cyclohexyl triphenyl phosphonium iodide, cyclohexyl triphenyl phosphonium bromide, cyclohexyl triphenyl phosphonium chloride, cyclohexyl triphenyl phosphonium acetate, cyclohexyl triphenyl phosphonium acetate·acetic acid complex, cyclohexyl triphenyl phosphonium phosphate, cyclohexyl triphenyl phosphonium oxalate, cycloheptyl triphenyl phosphonium iodide, cycloheptyl triphenyl phosphonium bromide, cycloheptyl triphenyl phosphonium chloride, cycloheptyl triphenyl phosphonium acetate, cycloheptyl triphenyl phosphonium acetate·acetic acid complex, cycloheptyl triphenyl phosphonium phosphate, cycloheptyl triphenyl phosphonium oxalate, or any combination thereof. A precatalyzed epoxy resin composition of Claim 3 wherein (a) the epoxy resin, component (A), is a diglycidyl ether of bisphenol A; and (b) the catalyst, component (B), is cyclopentyl triphenyl phosphonium iodide, cyclopentyl triphenyl phosphonium bromide, cyclopentyl triphenyl phosphonium chloride, cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclopentyl triphenyl phosphonium phosphate, cyclohexyl triphenyl phosphonium iodide, cyclohexyl triphenyl phosphonium bromide, cyclohexyl triphenyl phosphonium chloride, cyclohexyl triphenyl phosphonium acetate·acetic acid complex, cyclohexyl triphenyl phosphonium phosphate, or any combination thereof. A process for the preparation of advanced epoxy resins by reacting (A) at least one epoxy resin having an average of more than one but not more than 2 vicinal epoxy groups per molecule; with (B) at least one compound having 2 aromatic hydroxyl groups per molecule; in the presence of (C) a triphenyl phosphonium catalyst; characterized in that a cycloalkyl triphenyl phosphonium compound is employed as the triphenyl phosphonium catalyst. A process of Claim 5 wherein (a) components (A) and (B) are employed in amounts which provide a ratio of phenolic hydroxyl groups to epoxy groups of from 0.01:1 to 2:1; (b) the triphenyl phosphonium catalyst, component (C), is employed in an amount of from 0.0001 to 0.1 mole of catalyst per mole of the epoxy resin, component (A); (c) component (A) is an epoxy resin or mixture of epoxy resins represented by the following formulas II or III wherein each A is independently a divalent hydrocarbyl or substituted hydrocarbyl group having from 1 to 12 carbon atoms; each R′ is independently hydrogen or an alkyl group having from 1 to 4 carbon atoms; each X is independently hydrogen or a hydrocarbyl or substituted hydrocarbyl or hydrocarbyloxy or substituted hydrocarbyloxy group having from to 12 carbon atoms or a halogen atom; each n independently has a value of zero or 1; and n′ has an average value from zero to 0.5; (d) the phenolic hydroxyl containing compound, component (B) is a compound or mixture of compounds represented by the following formulas IV or V wherein A, X and n are as defined above; and (e) the triphenyl phosphonium catalyst, component (C) is represented by the following formula I wherein Q is a cycloalkyl or alkyl or halo substituted cycloalkyl group having from 3 to 8 carbon atoms in the cycloalkyl ring; each R is independently hydrogen, a halogen, or a hydrocarbyl group having from 1 to 12 carbon atoms; Z is an anion A process of Claim 5 wherein (a) the epoxy resin, component (A), is a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, a diglycidyl ether of bisphenol K, a diglycidyl ether of bisphenol S or a mixture of such glycidyl ethers; (b) the phenolic hydroxyl containing compound, component (B), is bisphenol A, bisphenol F, bisphenol K, bisphenol S or a mixture of such compounds; and (c) the catalyst, component (C), is cyclopropyl triphenyl phosphonium iodide, cyclopropyl triphenyl phosphonium bromide, cyclopropyl triphenyl phosphonium chloride, cyclopropyl triphenyl phosphonium acetate, cyclopropyl triphenyl phosphonium acetate·acetic acid complex, cyclopropyl triphenyl phosphonium phosphate, cyclopropyl triphenyl phosphonium oxalate, cyclopentyl triphenyl phosphonium iodide, cyclopentyl triphenyl phosphonium bromide, cyclopentyl triphenyl phosphonium chloride, cyclopentyl triphenyl phosphonium acetate, cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclopentyl triphenyl phosphonium phosphate, cyclopentyl triphenyl phosphonium oxalate, cyclohexyl triphenyl phosphonium iodide, cyclohexyl triphenyl phosphonium bromide, cyclohexyl triphenyl phosphonium chloride, cyclohexyl triphenyl phosphonium acetate, cyclohexyl triphenyl phosphonium acetate·acetic acid complex, cyclohexyl triphenyl phosphonium phosphate, cyclohexyl triphenyl phosphonium oxalate, cycloheptyl triphenyl phosphonium iodide, cycloheptyl triphenyl phosphonium bromide, cycloheptyl triphenyl phosphonium chloride, cycloheptyl triphenyl phosphonium acetate, cycloheptyl triphenyl phosphonium acetate·acetic acid complex, cycloheptyl triphenyl phosphonium phosphate, cycloheptyl triphenyl phosphonium oxalate, or any combination thereof. A process of Claim 5 wherein (a) the epoxy resin, component (A), is a diglycidyl ether of bisphenol A; (b) the phenolic hydroxyl containing compound, component (B), is bisphenol A; and (c) the catalyst, component (C), is cyclopentyl triphenyl phosphonium iodide, cyclopentyl triphenyl phosphonium bromide, cyclopentyl triphenyl phosphonium chloride, cyclopentyl triphenyl phosphonium acetate·acetic acid complex, cyclopentyl triphenyl phosphonium phosphate, cyclohexyl triphenyl phosphonium iodide, cyclohexyl triphenyl phosphonium bromide, cyclohexyl triphenyl phosphonium chloride, cyclohexyl triphenyl phosphonium acetate·acetic acid complex, cyclohexyl triphenyl phosphonium phosphate, or any combination thereof.

Inventors: HO LOAN AN, PHAM HA QUOC, HO, LOAN AN, PHAM, HA QUOC
Applicants: DOW CHEMICAL CO, THE DOW CHEMICAL COMPANY
Application year: 1989
Main classification: C08G59
IPC codes: C08G59