CA1257446A - Process for reducing the total halide content of an epoxy resin - Google Patents
Process for reducing the total halide content of an epoxy resinInfo
- Publication number
- CA1257446A CA1257446A CA000495522A CA495522A CA1257446A CA 1257446 A CA1257446 A CA 1257446A CA 000495522 A CA000495522 A CA 000495522A CA 495522 A CA495522 A CA 495522A CA 1257446 A CA1257446 A CA 1257446A
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- Prior art keywords
- weight
- epoxy resin
- percent
- ketone
- alkali metal
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/14—Polycondensates modified by chemical after-treatment
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/02—Polycondensates containing more than one epoxy group per molecule
Abstract
ABSTRACT OF THE DISCLOSURE
The total halide content of epoxy resins is reduced by heating a resin containing halide dissolved in a unique solvent system containing at least one ketone, at least one aromatic hydrocarbon and at least one compound containing at least one aliphatic hydroxyl group in the presence of an alkali metal hydroxide for a time sufficient to reduce the total halide content; washing the resin with water, a dilute aqueous solution of a weak inorganic acid or acid salt; and then recovering the resultant resin. The epoxy resin having a low halide content is used in the electronics industry as an encapsulant, potting compound electrical laminate, and the like.
The total halide content of epoxy resins is reduced by heating a resin containing halide dissolved in a unique solvent system containing at least one ketone, at least one aromatic hydrocarbon and at least one compound containing at least one aliphatic hydroxyl group in the presence of an alkali metal hydroxide for a time sufficient to reduce the total halide content; washing the resin with water, a dilute aqueous solution of a weak inorganic acid or acid salt; and then recovering the resultant resin. The epoxy resin having a low halide content is used in the electronics industry as an encapsulant, potting compound electrical laminate, and the like.
Description
7~4.6 A PROCESS FOR REDUCING THE TOTAL
HALIDE CONTENT OF AN EPOXY RESIN
The present invention pertains to a process for reducing the hydrolyzable and/or bound (total) halide content o an epoxy resin.
Epoxy resins are used in the electronics industry as encapsulants, potting compounds, electrical laminates and the like. This industry has discovered that the halide content of the epoxy resin adversely affects the electrical properties of the resultant end products. The higher the halide content, the greater the detriment. The present invention provides a pro-cess for reducing the total (hydrolyzable and/or bound) halide content of epoxy resins.
The present invention pertains to a process for reducing the total halide content of an epoxy resin containing hydrolyzable and/or bound halide which pro-cess comprises (A) dissolving said epoxy resin in a solvent system which comprises 33,575B-F ~1-~57~6 (1) from 25 to 75, preferably from S0 to 75 percent by weight of at leas-t one ketone and
HALIDE CONTENT OF AN EPOXY RESIN
The present invention pertains to a process for reducing the hydrolyzable and/or bound (total) halide content o an epoxy resin.
Epoxy resins are used in the electronics industry as encapsulants, potting compounds, electrical laminates and the like. This industry has discovered that the halide content of the epoxy resin adversely affects the electrical properties of the resultant end products. The higher the halide content, the greater the detriment. The present invention provides a pro-cess for reducing the total (hydrolyzable and/or bound) halide content of epoxy resins.
The present invention pertains to a process for reducing the total halide content of an epoxy resin containing hydrolyzable and/or bound halide which pro-cess comprises (A) dissolving said epoxy resin in a solvent system which comprises 33,575B-F ~1-~57~6 (1) from 25 to 75, preferably from S0 to 75 percent by weight of at leas-t one ketone and
(2) from 75 to 25, preferably from 50 to 25 percent by weight of at least one aromatic hydrocarbon;
(B) adding from 0.1 to 5, preferably from 0.2 to 1 percent by weight based upon the weight of said epoxy resin of at least one compound having at least one aliphatic hydroxyl group per molecule as a cosolvent;
(C) heating the resultant solution to a temper-ature of from 50C up to 200C;
(D) adding from 0.25 to 10, preferably from 1 to S, most preferably from 1 to 3 moles of an alkali metal hydroxide per equivalent of total halide;
(E) continuing the heating for a time sufficient to reduce the total halide content of said ~poxy resin;
~F) washing the product from step (E) wi-th either water, a dilute aqueous solution of a weak inorganic acid, acid salt or a combination thereof; and ~G) recovering the resultant epoxy resin having a reduced total halide content from the product of step (F).
Suitable epoxy resins which can be employed herein include any epoxy resin con-taining an average of more than one vicinal epoxy group per molecule and which contains an undesirable quantity of ~otal, hydro-lyzable and/or bound halide.
33,575B-F -2-~L~S~6 Particularly suitable epoxy resins include the polyglycidyl ether of compounds having an average of more than one hydroxyl group per molecule and which contains at least 10 parts per million total halide such as, for example, glycidyl ethers of bisphenols, glycidyl ethers of phenol formaldehyde epoxy resins, cresol formaldehyde epoxy resins, and mixtures thereof.
Suitable ketones which can be employed herein in~lude, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and mixtures thereof.
Suitable aromatic hydrocarbons which can be employed herein include, for example, benzene, toluene, xylene, and mixtures thereof.
Suitable compounds having at least one ali-phatic hydroxyl group per molecule include, for example, aliphatic alcohols, diols and triols and polyoxyalkylene compounds having from 1 to 3 hydroxyl groups per molecule having an average molecular weight of from 100 to 600, preferably from 200 to 400, and mixtures thereof.
Particularly suitable are the polyoxyethylene glycols sometimes referred to as polyethylene glycols, and mixtures thereof.
Suitable alkali metal hydroxides include, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, and mixtures thereof. The alkali metal can be employed in solid form or as an aqueous solution, preferably as an aqueous solution in a concentration of 33,575B-F 3-74~a~
from 10 to 70, preferably from 40 to 60 percent alkali metal hydroxide by weight.
The heating can be conducted at atmospheric or superatmospheric pressure. When relatively low 5 boiling solvents are employed, superatmospheri~ pres-sure is usually required. It is preferred to employ a temperature of from 50C up to 200C, more preferably from 100 to 130C. It is preferable to not employ a temperature above the boiling point of the solvent system. For low boiling solvent systems, pressure can be employed so that temperatures above the boiling point can be employed.
When washing the epoxy resin to remove the salt formed and any unreacted alkali metal hydroxide, it is preferred to employ a plurality of washing steps employing as the first wash a dilute solution of an inorganic acid or a dilute solution of an inorganic acid salt, preferably acids or acid salts having a pKa value of from 2 to 10, preferably from 2 to 7.
Suitable acids and acid salts include, for example, phosphoric acid, mono-sodium phosphate, di-sodium phosphate, carbonic acid, boric acid, and mixtures thereof.
The epoxy resin is ultimately recovered by subjecting the organic phase from the washing procedure to distillation to remove the solvents from the epoxy resin.
The following examples are illustrative of the present invention, but are not to be construed as to limiting the scope thereof in any manner.
33,575B-F -4-~%~
EXAMPLE
75 G of a cresol-formaldehyde epoxy novolac resin having an average epoxide equivalent weight (EEW) of about 220 and an average epoxy functionality of 5 about 6 containing 3536 ppm hydrolyzable chlorlde by weight was dissolved in 75 g of a 75/25 by weight mixture of methyl ethyl ketone (MEK) and toluene. 0.38 G (0.5 weight percent based on epoxy resin) of poly-ethylene glycol having an average molecular weight of about 400 was added to the solution and the solution was heated to 80C with stirring. 1. 05 G of 50 percent agueous potassium hydroxide (1.25 eq. KOH to 1 eq. of hydrolyzable chloride) was added all at once and the reaction mixture was maintained at 80 for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent resin concentration with MEK/toluene solvent mix, neutralized with dilute H3PO4 and then washed with water 3 to 4 times to remove NaCl.
The organic phase from the water washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac resin with a hydrolyzable chloride content of 7 ppm was obtained.
The procedure of Example 1 was followed employing the following components and conditions.
100 Grams of a cresol-formaldehyde epoxy novolac resin having an average EEW of 220 and an average epoxy functionality of 6 and containing 3700 ppm hydro-lyzable chloride.
33,575B-F -5-~2S744Ei 100 Grams of a 75/25 mixture of MEK/toluene Sufficient quantity of different cosolvents such that the amount of cosolvent was 0.5 percent by weight based on the epoxy resin.
1 Gram (1.2 equiv. per hydrolyzable chlorine equiv.) of a 50 percent aqueous solution of NaOH
The reactions were conducted at 80C for 2 hours (7200 s). The results are given in the following Table I.
TABLE I
COSOLVENTHYDROLYZABLE CHLORIDE,_p~
glycerine 181 methanol 95 isopropyl alcohol84 monomethyl ether of propylene glycol 83 tetraethylene glycol 54 polyethylene glycol (200 MW) 60 polyethylene glycol (300 MW) 55 polyethylene glycol (400 MW~ 54 polypropylene glycol (425 MW) 159 ' The procedure of Example 1 was followed employing the following components and conditions.
5 100 Grams of a cresol-formaldehyde epoxy novolac resin having an average EEW of 220, an average epoxy functionality of 6 and 3536 ppm hydrolyzable chloride.
33,575B~F -6-3L~
100 Grams of a 75/25 by weight mixture of MEK/toluene.
Several reactions were conducted at 80C for 2 hours ~7200 s) employing various guantities of either NaOH or KOH and with and without polyethylene glycol having an average MW of 400. The results are given in the following Table II.
TABLE _ EQUIV.
CAUSTIC
PER EQUIV. H~DROLYZABLE
CAUSTIC HXDROLYZABLE POLYETHYLENE CHLORIDE
TYPECHLORIDE GLYCOL, wt%* CONTENT,ppm NaOH 1.08 0 167 NaOH 1.08 0.5 107 KOH 1.08 0 113 KOH 1.08 0.5 48 NaOH 1.16 0.5 81 KOH 1.16 0.5 33 NaOH 1.25 0.5 34 KOH 1.25 0.5 7 *Based upon weight of epoxy resin.
To a one liter reaction vessel equipped with temperature and pressure control and indicating means, a means for the continuous addition of aqueous sodium hydroxide, a means for condensing and separating water from a codistillate mixture of water, solvent and epichlorohydrin and means for returning the solvent and epichlorohydrin was added 118.5 g (1 equivalent) of 33,575B-F -7-t cresol-formaldehyde novolac resin having an average hydroxyl equivalent wt. of 118.5 and average function-ality of about 6, 370 g (4 equivalents) of epichloro-hydrin and 247 g of the methyl ether of propylene glycol (1-methoxy-2-hydroxy propane) as a solvent.
After stirring at room temperature and atmospheric pressure to thoroughly mix the contents, the tem-perature was raised to 65C and the pressure was reduced to 180 mm ~g (24 kPa) absolute. To the resultant solution was continuously added 75.2 g (0.94 equivalent) of 50 percent aqueous sodium hydroxide solution at a constant rate over a period of 4 hours (14400 s). During the addition of the sodium hydrox~
ide, the water was removed by codistilling with epi-chlorohydrin and solvent. The distillate was condensedthereby forming two distinct phases, an aqueous phase (top) and an organic epichlorohydrin-solvent phase (bottom). The organic phase was continuously returned to the reactor. After completion of the sodium hydrox-ide addition, the reaction mixture was maintained at atemperature of 65 and a pressure of about 180 mm ~Ig (24 kPa) absolute for an additional 30 minutes (1800 s).
The resulting cresol-formaldehyde epoxy novolac resin was then distilled under full vacuum and temperature up to 170C to remove all epichlorohydrin and 1-methoxy-2 -hydroxy propane.
To the molten çresol-formaldehyde epoxy novolac resin was added an equal weight of a 75/25 by weight mixture of methyl ethyl ketone (MEK) and tol-uene. A sample of the slurry was taken and was foundto conta.in 1200 ppm hydrolyzable chloride. 0.87 g (0.5 weight percent based on epoxy resin) of polyethylene glycol having an average molecular weigh-t of 400 was , 33,575B-F -8-added to the mixture and the mixture was heated to 80C
with stirring. 0.86 g of 50 percent aqueous potassium hydroxide (1.3 eq. KOH to 1 eq. hydrolyzable chloride) was added all at once and the reaction mixture was maintained at 80C for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent resin concentration with MEK/toluene (75/25) solvent mixture, neutralized with CO2 and then washed with water 4 to 5 times to remove NaCl.
The organic phase rom the water washes was placed on a rotary evaporator under a full vacuum and temperature of 170C to remove the solvent completely.
A purified cresol-formaldehyde epoxy novolac resin with a hydroly2able chloride content of 7 ppm was obtained.
625 G of cresol epoxy novolac containing 553 ppm hydrolyzable chloride and 930 ppm bound chloride (total chloride = 1483 ppm) was dissolved in 625 g of 75/25 by weight MEK/toluene solvent mixture. 1.87S G
(0.3 weight percent based on resin) of polyethylene glycol having an average molecular weight of 400 was added to the solution and the solution was heated to 85C with stirring. 6.7 g of 45 percent aqueous potas-sium hydroxide (2.1 eq. caustic to 1 eq. chlorine) wasadded all at once and the reaction mix-ture was main-tained at 85C for 6 hours (21,600 s) with good agita-tion.
- The reaction mixture was diluted to 20 per-cent solid concentration with MEK/toluene solvent d 33,575B-F -9-;74~6 mixture, neutralized with dilute H3P04 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac with hydrolyzable chloride content of 7 ppm and bound chloride content of 263 ppm (total chloride =
270) was obtained.
100 G of a diglycidyl ether of bisphenol A
epoxy resin containing 300 ppm hydrolyzable chloride and 900 ppm bound chloride (total chloride = 1200 ppm) was dissolved in 100 g of a MEK/toluene solvent mix-ture. 0.5 g (0.5 weight percent based on resin) of polyethylene glycol having a molecular weight of 400 was added to the solution and the solution was heated to 80C with stirring. 0.84 G of 45 percent aqueous potassium hydroxide (2 eq. caustic to 1 eq. chlorine) was added all at once and the reaction mixture was maintained at 80C for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent solid concentration with MEK/toluene solvent mixture, neutralized with CO2 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified diglycidyl ether of bisphenol A epoxy resin with hydrolyzable chloride of 3 ppm and bound chloride of 540 ppm (total chloride = 543 ppm) was obtained.
; 33,575B-F -lO-In a stainless steel 2-liter pressure reac-tion vessel, 625 g o cresol epoxy novolac containing 553 ppm hydrolyzable chloride and 930 ppm bound chlo-ride (-total chloride = 1483 ppm) was dissolved in 625 g of a 75/25 by weight MEK~toluene solvent mi~ture.
1.875 G (0.3 weight percent based on resin) of poly-ethylene glycol having an average molecular weight of 400 was added to the solution and the solution was heated to 120C with stirring. 3.9 G of 45 percent a~leous potassium hydroxide (1.2 eg. caustic to 1 e~.
chlorine) was added all at once and the reaction mix-ture was maintained at 120C for 1 hour (3600 s~ with good agitation.
The reaction mixture was diluted to 20 per-cent solid ~oncentration with MEK/toluene solvent mixture, neutralized with CO2 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac with hydrolyzable chloride content of 8 ppm and bound chloride content of 260 ppm (total chloride =
268) was obtained.
~; 33,575B-F
(B) adding from 0.1 to 5, preferably from 0.2 to 1 percent by weight based upon the weight of said epoxy resin of at least one compound having at least one aliphatic hydroxyl group per molecule as a cosolvent;
(C) heating the resultant solution to a temper-ature of from 50C up to 200C;
(D) adding from 0.25 to 10, preferably from 1 to S, most preferably from 1 to 3 moles of an alkali metal hydroxide per equivalent of total halide;
(E) continuing the heating for a time sufficient to reduce the total halide content of said ~poxy resin;
~F) washing the product from step (E) wi-th either water, a dilute aqueous solution of a weak inorganic acid, acid salt or a combination thereof; and ~G) recovering the resultant epoxy resin having a reduced total halide content from the product of step (F).
Suitable epoxy resins which can be employed herein include any epoxy resin con-taining an average of more than one vicinal epoxy group per molecule and which contains an undesirable quantity of ~otal, hydro-lyzable and/or bound halide.
33,575B-F -2-~L~S~6 Particularly suitable epoxy resins include the polyglycidyl ether of compounds having an average of more than one hydroxyl group per molecule and which contains at least 10 parts per million total halide such as, for example, glycidyl ethers of bisphenols, glycidyl ethers of phenol formaldehyde epoxy resins, cresol formaldehyde epoxy resins, and mixtures thereof.
Suitable ketones which can be employed herein in~lude, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and mixtures thereof.
Suitable aromatic hydrocarbons which can be employed herein include, for example, benzene, toluene, xylene, and mixtures thereof.
Suitable compounds having at least one ali-phatic hydroxyl group per molecule include, for example, aliphatic alcohols, diols and triols and polyoxyalkylene compounds having from 1 to 3 hydroxyl groups per molecule having an average molecular weight of from 100 to 600, preferably from 200 to 400, and mixtures thereof.
Particularly suitable are the polyoxyethylene glycols sometimes referred to as polyethylene glycols, and mixtures thereof.
Suitable alkali metal hydroxides include, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, and mixtures thereof. The alkali metal can be employed in solid form or as an aqueous solution, preferably as an aqueous solution in a concentration of 33,575B-F 3-74~a~
from 10 to 70, preferably from 40 to 60 percent alkali metal hydroxide by weight.
The heating can be conducted at atmospheric or superatmospheric pressure. When relatively low 5 boiling solvents are employed, superatmospheri~ pres-sure is usually required. It is preferred to employ a temperature of from 50C up to 200C, more preferably from 100 to 130C. It is preferable to not employ a temperature above the boiling point of the solvent system. For low boiling solvent systems, pressure can be employed so that temperatures above the boiling point can be employed.
When washing the epoxy resin to remove the salt formed and any unreacted alkali metal hydroxide, it is preferred to employ a plurality of washing steps employing as the first wash a dilute solution of an inorganic acid or a dilute solution of an inorganic acid salt, preferably acids or acid salts having a pKa value of from 2 to 10, preferably from 2 to 7.
Suitable acids and acid salts include, for example, phosphoric acid, mono-sodium phosphate, di-sodium phosphate, carbonic acid, boric acid, and mixtures thereof.
The epoxy resin is ultimately recovered by subjecting the organic phase from the washing procedure to distillation to remove the solvents from the epoxy resin.
The following examples are illustrative of the present invention, but are not to be construed as to limiting the scope thereof in any manner.
33,575B-F -4-~%~
EXAMPLE
75 G of a cresol-formaldehyde epoxy novolac resin having an average epoxide equivalent weight (EEW) of about 220 and an average epoxy functionality of 5 about 6 containing 3536 ppm hydrolyzable chlorlde by weight was dissolved in 75 g of a 75/25 by weight mixture of methyl ethyl ketone (MEK) and toluene. 0.38 G (0.5 weight percent based on epoxy resin) of poly-ethylene glycol having an average molecular weight of about 400 was added to the solution and the solution was heated to 80C with stirring. 1. 05 G of 50 percent agueous potassium hydroxide (1.25 eq. KOH to 1 eq. of hydrolyzable chloride) was added all at once and the reaction mixture was maintained at 80 for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent resin concentration with MEK/toluene solvent mix, neutralized with dilute H3PO4 and then washed with water 3 to 4 times to remove NaCl.
The organic phase from the water washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac resin with a hydrolyzable chloride content of 7 ppm was obtained.
The procedure of Example 1 was followed employing the following components and conditions.
100 Grams of a cresol-formaldehyde epoxy novolac resin having an average EEW of 220 and an average epoxy functionality of 6 and containing 3700 ppm hydro-lyzable chloride.
33,575B-F -5-~2S744Ei 100 Grams of a 75/25 mixture of MEK/toluene Sufficient quantity of different cosolvents such that the amount of cosolvent was 0.5 percent by weight based on the epoxy resin.
1 Gram (1.2 equiv. per hydrolyzable chlorine equiv.) of a 50 percent aqueous solution of NaOH
The reactions were conducted at 80C for 2 hours (7200 s). The results are given in the following Table I.
TABLE I
COSOLVENTHYDROLYZABLE CHLORIDE,_p~
glycerine 181 methanol 95 isopropyl alcohol84 monomethyl ether of propylene glycol 83 tetraethylene glycol 54 polyethylene glycol (200 MW) 60 polyethylene glycol (300 MW) 55 polyethylene glycol (400 MW~ 54 polypropylene glycol (425 MW) 159 ' The procedure of Example 1 was followed employing the following components and conditions.
5 100 Grams of a cresol-formaldehyde epoxy novolac resin having an average EEW of 220, an average epoxy functionality of 6 and 3536 ppm hydrolyzable chloride.
33,575B~F -6-3L~
100 Grams of a 75/25 by weight mixture of MEK/toluene.
Several reactions were conducted at 80C for 2 hours ~7200 s) employing various guantities of either NaOH or KOH and with and without polyethylene glycol having an average MW of 400. The results are given in the following Table II.
TABLE _ EQUIV.
CAUSTIC
PER EQUIV. H~DROLYZABLE
CAUSTIC HXDROLYZABLE POLYETHYLENE CHLORIDE
TYPECHLORIDE GLYCOL, wt%* CONTENT,ppm NaOH 1.08 0 167 NaOH 1.08 0.5 107 KOH 1.08 0 113 KOH 1.08 0.5 48 NaOH 1.16 0.5 81 KOH 1.16 0.5 33 NaOH 1.25 0.5 34 KOH 1.25 0.5 7 *Based upon weight of epoxy resin.
To a one liter reaction vessel equipped with temperature and pressure control and indicating means, a means for the continuous addition of aqueous sodium hydroxide, a means for condensing and separating water from a codistillate mixture of water, solvent and epichlorohydrin and means for returning the solvent and epichlorohydrin was added 118.5 g (1 equivalent) of 33,575B-F -7-t cresol-formaldehyde novolac resin having an average hydroxyl equivalent wt. of 118.5 and average function-ality of about 6, 370 g (4 equivalents) of epichloro-hydrin and 247 g of the methyl ether of propylene glycol (1-methoxy-2-hydroxy propane) as a solvent.
After stirring at room temperature and atmospheric pressure to thoroughly mix the contents, the tem-perature was raised to 65C and the pressure was reduced to 180 mm ~g (24 kPa) absolute. To the resultant solution was continuously added 75.2 g (0.94 equivalent) of 50 percent aqueous sodium hydroxide solution at a constant rate over a period of 4 hours (14400 s). During the addition of the sodium hydrox~
ide, the water was removed by codistilling with epi-chlorohydrin and solvent. The distillate was condensedthereby forming two distinct phases, an aqueous phase (top) and an organic epichlorohydrin-solvent phase (bottom). The organic phase was continuously returned to the reactor. After completion of the sodium hydrox-ide addition, the reaction mixture was maintained at atemperature of 65 and a pressure of about 180 mm ~Ig (24 kPa) absolute for an additional 30 minutes (1800 s).
The resulting cresol-formaldehyde epoxy novolac resin was then distilled under full vacuum and temperature up to 170C to remove all epichlorohydrin and 1-methoxy-2 -hydroxy propane.
To the molten çresol-formaldehyde epoxy novolac resin was added an equal weight of a 75/25 by weight mixture of methyl ethyl ketone (MEK) and tol-uene. A sample of the slurry was taken and was foundto conta.in 1200 ppm hydrolyzable chloride. 0.87 g (0.5 weight percent based on epoxy resin) of polyethylene glycol having an average molecular weigh-t of 400 was , 33,575B-F -8-added to the mixture and the mixture was heated to 80C
with stirring. 0.86 g of 50 percent aqueous potassium hydroxide (1.3 eq. KOH to 1 eq. hydrolyzable chloride) was added all at once and the reaction mixture was maintained at 80C for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent resin concentration with MEK/toluene (75/25) solvent mixture, neutralized with CO2 and then washed with water 4 to 5 times to remove NaCl.
The organic phase rom the water washes was placed on a rotary evaporator under a full vacuum and temperature of 170C to remove the solvent completely.
A purified cresol-formaldehyde epoxy novolac resin with a hydroly2able chloride content of 7 ppm was obtained.
625 G of cresol epoxy novolac containing 553 ppm hydrolyzable chloride and 930 ppm bound chloride (total chloride = 1483 ppm) was dissolved in 625 g of 75/25 by weight MEK/toluene solvent mixture. 1.87S G
(0.3 weight percent based on resin) of polyethylene glycol having an average molecular weight of 400 was added to the solution and the solution was heated to 85C with stirring. 6.7 g of 45 percent aqueous potas-sium hydroxide (2.1 eq. caustic to 1 eq. chlorine) wasadded all at once and the reaction mix-ture was main-tained at 85C for 6 hours (21,600 s) with good agita-tion.
- The reaction mixture was diluted to 20 per-cent solid concentration with MEK/toluene solvent d 33,575B-F -9-;74~6 mixture, neutralized with dilute H3P04 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac with hydrolyzable chloride content of 7 ppm and bound chloride content of 263 ppm (total chloride =
270) was obtained.
100 G of a diglycidyl ether of bisphenol A
epoxy resin containing 300 ppm hydrolyzable chloride and 900 ppm bound chloride (total chloride = 1200 ppm) was dissolved in 100 g of a MEK/toluene solvent mix-ture. 0.5 g (0.5 weight percent based on resin) of polyethylene glycol having a molecular weight of 400 was added to the solution and the solution was heated to 80C with stirring. 0.84 G of 45 percent aqueous potassium hydroxide (2 eq. caustic to 1 eq. chlorine) was added all at once and the reaction mixture was maintained at 80C for 2 hours (7200 s) with good agitation.
The reaction mixture was diluted to 20 per-cent solid concentration with MEK/toluene solvent mixture, neutralized with CO2 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified diglycidyl ether of bisphenol A epoxy resin with hydrolyzable chloride of 3 ppm and bound chloride of 540 ppm (total chloride = 543 ppm) was obtained.
; 33,575B-F -lO-In a stainless steel 2-liter pressure reac-tion vessel, 625 g o cresol epoxy novolac containing 553 ppm hydrolyzable chloride and 930 ppm bound chlo-ride (-total chloride = 1483 ppm) was dissolved in 625 g of a 75/25 by weight MEK~toluene solvent mi~ture.
1.875 G (0.3 weight percent based on resin) of poly-ethylene glycol having an average molecular weight of 400 was added to the solution and the solution was heated to 120C with stirring. 3.9 G of 45 percent a~leous potassium hydroxide (1.2 eg. caustic to 1 e~.
chlorine) was added all at once and the reaction mix-ture was maintained at 120C for 1 hour (3600 s~ with good agitation.
The reaction mixture was diluted to 20 per-cent solid ~oncentration with MEK/toluene solvent mixture, neutralized with CO2 and then washed with water several times to remove NaCl.
The organic phase from the washes was placed on a rotary evaporator under a full vacuum and 170C to remove the solvent completely. A purified cresol epoxy novolac with hydrolyzable chloride content of 8 ppm and bound chloride content of 260 ppm (total chloride =
268) was obtained.
~; 33,575B-F
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A process for reducing the total halide content of an epoxy resin containing at least one of hydrolyzable or bound halide which process comprises (A) dissolving said epoxy resin in a solvent system which comprises (1) from 25 to 75 percent by weight of at least one ketone and (2) from 75 to 25 percent by weight of at least one aromatic hydrocarbon;
(B) adding from 0.1 to 5 percent by weight based upon the weight of said epoxy resin of at least one compound having at least one ali-phatic hydroxyl group per molecule as a cosolvent;
(C) heating the resultant solution to a temper-ature of from 50°C up to 200°C;
(D) adding from 0.25 to 10 moles of an alkali metal hydroxide per equivalent of total halide;
(E) continuing the heating for a time sufficient to reduce the total halide content of said epoxy resin;
(F) washing the product from step (E) with either water, a dilute aqueous solution of a weak inorganic acid, acid salt or a combination thereof; and (G) recovering the resultant epoxy resin having a reduced total halide content from the product of step (F).
(B) adding from 0.1 to 5 percent by weight based upon the weight of said epoxy resin of at least one compound having at least one ali-phatic hydroxyl group per molecule as a cosolvent;
(C) heating the resultant solution to a temper-ature of from 50°C up to 200°C;
(D) adding from 0.25 to 10 moles of an alkali metal hydroxide per equivalent of total halide;
(E) continuing the heating for a time sufficient to reduce the total halide content of said epoxy resin;
(F) washing the product from step (E) with either water, a dilute aqueous solution of a weak inorganic acid, acid salt or a combination thereof; and (G) recovering the resultant epoxy resin having a reduced total halide content from the product of step (F).
2. A method of Claim 1 wherein (i) in step (A) said solvent system com-prises from 50 to 75 percent by weight of one ketone and said aromatic hydro-carbon is present in quantities of from 50 to 25 percent by weight;
(ii) in step (B) said cosolvent is present in quantity of from 0.2 to 1 weight percent based upon the weight of the epoxy resin;
(iii) in step (C), said heating is conducted at a temperature of from 100°C to 130°C;
and (iv) in step (D), the alkali metal hydroxide is present in a quantity of from 1 to 5 moles per equivalent of total halide.
(ii) in step (B) said cosolvent is present in quantity of from 0.2 to 1 weight percent based upon the weight of the epoxy resin;
(iii) in step (C), said heating is conducted at a temperature of from 100°C to 130°C;
and (iv) in step (D), the alkali metal hydroxide is present in a quantity of from 1 to 5 moles per equivalent of total halide.
3. A method of Claim 2 wherein (i) said ketone is methyl ethyl ketone or methyl isobutyl ketone;
(ii) said aromatic hydrocarbon is benzene, toluene or xylene;
(iii) said cosolvent is a polyoxyethylene glycol or polyoxypropylene glycol having an average molecular weight of from 100 to 600;
(iv) said alkali metal hydroxide is sodium hydroxide or potassium hydroxide; and (v) in step (D), the alkali metal hydroxide is present in a quantity of from 1 to 3 moles per equivalent of total halide.
(ii) said aromatic hydrocarbon is benzene, toluene or xylene;
(iii) said cosolvent is a polyoxyethylene glycol or polyoxypropylene glycol having an average molecular weight of from 100 to 600;
(iv) said alkali metal hydroxide is sodium hydroxide or potassium hydroxide; and (v) in step (D), the alkali metal hydroxide is present in a quantity of from 1 to 3 moles per equivalent of total halide.
4. A method of Claim 3 wherein (i) said ketone is methyl ethyl ketone;
(ii) said aromatic hydrocarbon is toluene;
(iii) said cosolvent is polyoxyethylene glycol having an average molecular weight of from 200 to 400; and (iv) said alkali metal hydroxide is potassium hydroxide.
(ii) said aromatic hydrocarbon is toluene;
(iii) said cosolvent is polyoxyethylene glycol having an average molecular weight of from 200 to 400; and (iv) said alkali metal hydroxide is potassium hydroxide.
5. A method of Claim 4 wherein in step (F), said product from step (E) is washed at least once with a dilute solution of a weak inorganic acid.
6. A method of Claim 5 wherein said weak inorganic acid is phosphoric acid or carbonic acid.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US67277584A | 1984-11-19 | 1984-11-19 | |
| US672,775 | 1984-11-19 | ||
| US76297185A | 1985-08-06 | 1985-08-06 | |
| US762,971 | 1985-08-06 | ||
| US06/773,500 US4585838A (en) | 1985-08-06 | 1985-09-09 | Process for preparing epoxy resins containing low levels of total halide |
| US773,500 | 1985-09-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1257446A true CA1257446A (en) | 1989-07-11 |
Family
ID=27418256
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000495522A Expired CA1257446A (en) | 1984-11-19 | 1985-11-18 | Process for reducing the total halide content of an epoxy resin |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0202277A4 (en) |
| KR (1) | KR900001943B1 (en) |
| CN (1) | CN1004356B (en) |
| AU (1) | AU560379B2 (en) |
| BR (1) | BR8507064A (en) |
| CA (1) | CA1257446A (en) |
| ES (1) | ES8701206A1 (en) |
| FI (1) | FI862961A (en) |
| IL (1) | IL77036A (en) |
| MY (1) | MY101828A (en) |
| NO (1) | NO165078C (en) |
| WO (1) | WO1986003210A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4785061A (en) * | 1987-08-13 | 1988-11-15 | The Dow Chemical Company | Method for reducing the aliphatic halide content of epoxy resins using a solvent mixture including a polar aprotic solvent |
| US7955498B2 (en) * | 2008-12-16 | 2011-06-07 | Chevron, U.S.A. Inc. | Reduction of organic halide contamination in hydrocarbon products |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE503550A (en) * | 1950-05-27 | |||
| BE546441A (en) * | 1955-03-28 | |||
| US2943095A (en) * | 1955-06-28 | 1960-06-28 | Union Carbide Corp | Process for preparing glycidyl polyethers of polyhydric phenols |
| NL270270A (en) * | 1960-10-17 | |||
| US3928288A (en) * | 1973-04-11 | 1975-12-23 | Dow Chemical Co | Epoxy novolac resins having a narrow molecular weight distribution and process therefor |
| JPS5824578A (en) * | 1981-08-05 | 1983-02-14 | Mitsui Petrochem Ind Ltd | Preparation of glycidyl ether |
| US4447598A (en) * | 1983-04-07 | 1984-05-08 | The Dow Chemical Company | Method of preparing epoxy resins having low hydrolyzable chloride contents |
| US4485221A (en) * | 1983-11-03 | 1984-11-27 | Ciba-Geigy Corporation | Process for making epoxy novolac resins with low hydrolyzable chlorine and low ionic chloride content |
-
1985
- 1985-11-08 CN CN85108970.4A patent/CN1004356B/en not_active Expired
- 1985-11-12 WO PCT/US1985/002210 patent/WO1986003210A1/en not_active Application Discontinuation
- 1985-11-12 EP EP19850905721 patent/EP0202277A4/en not_active Ceased
- 1985-11-12 AU AU50915/85A patent/AU560379B2/en not_active Ceased
- 1985-11-12 KR KR1019860700472A patent/KR900001943B1/en not_active IP Right Cessation
- 1985-11-12 BR BR8507064A patent/BR8507064A/en unknown
- 1985-11-13 IL IL77036A patent/IL77036A/en not_active IP Right Cessation
- 1985-11-18 CA CA000495522A patent/CA1257446A/en not_active Expired
- 1985-11-18 ES ES548999A patent/ES8701206A1/en not_active Expired
-
1986
- 1986-07-16 FI FI862961A patent/FI862961A/en not_active Application Discontinuation
- 1986-07-18 NO NO862909A patent/NO165078C/en unknown
-
1987
- 1987-08-25 MY MYPI87001452A patent/MY101828A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ES548999A0 (en) | 1986-11-16 |
| NO165078C (en) | 1990-12-19 |
| EP0202277A1 (en) | 1986-11-26 |
| CN1004356B (en) | 1989-05-31 |
| NO165078B (en) | 1990-09-10 |
| AU5091585A (en) | 1986-06-18 |
| IL77036A (en) | 1989-07-31 |
| AU560379B2 (en) | 1987-04-02 |
| FI862961A0 (en) | 1986-07-16 |
| IL77036A0 (en) | 1986-04-29 |
| WO1986003210A1 (en) | 1986-06-05 |
| FI862961A (en) | 1986-07-16 |
| ES8701206A1 (en) | 1986-11-16 |
| NO862909L (en) | 1986-07-18 |
| KR900001943B1 (en) | 1990-03-26 |
| NO862909D0 (en) | 1986-07-18 |
| KR870700658A (en) | 1987-12-30 |
| MY101828A (en) | 1992-01-31 |
| BR8507064A (en) | 1987-05-05 |
| CN85108970A (en) | 1986-07-09 |
| EP0202277A4 (en) | 1987-12-07 |
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| MKEX | Expiry |