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

Definitions

• the present invention pertains to a process for reducing the hydrolyzable and/or bound (total) halide content of 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
• step (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) .
• Suitable epoxy resins which can be employed herein include any epoxy resin containing an average of more than one vicinal epoxy group per molecule and which contains an undesirable quantity of total, hydro ⁇ lyzable and/or bound halide.
• 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 include, 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.
• 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 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.
• superatmospheric pressure When relatively low boiling solvents are employed, superatmospheric pres ⁇ sure is usually required. It is preferred to employ a temperature of from 50°C up to 200°C, more preferably from 100° to 130°C. 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.
• 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-sodiu 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.
• 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 about 6 containing 3536 ppm hydrolyzable chloride by weight was dissolved in 75 g of a 75/25 by weight mixture of methyl ethyl ketone ( EK) 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 80°C with stirring.
• 1.05 G of 50 percent aqueous 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.
• reaction mixture was diluted to 20 per ⁇ cent resin concentration with MEK/toluene solvent mix, neutralized with dilute H 3 P0 and then washed with water 3 to 4 times to remove NaCl.
• Example 1 The procedure of Example 1 was followed employing the following components and conditions.
• COSOLVENT HYDROLYZABLE CHLORIDE __£___ glycerine 181 methanol 95 isopropyl alcohol 84 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
• Example 1 The procedure of Example 1 was followed employing the following components and conditions.
• the tem ⁇ perature was raised to 65°C and the pressure was reduced to 180 mm Hg (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).
• the sodium hydrox ⁇ ide the water was removed by codistilling with epi- chlorohydrin and solvent. The distillate was condensed thereby forming two distinct phases, an aqueous phase (top) and an organic epichlorohydrin-solvent phase (bottom) .
• the organic phase was continuously returned to the reactor.
• the reaction mixture was maintained at a temperature of 65° and a pressure of about 180 mm Hg (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 170°C .to remove all epichlorohydrin and l-methoxy-2- -hydroxy propane.
• reaction mixture was diluted to 20 per ⁇ cent resin concentration with MEK/toluene (75/25) solvent mixture, neutralized with C0 2 and then washed with water 4 to 5 times to remove NaCl.
• reaction mixture was diluted to 20 per- cent solid concentration with MEK/toluene solvent ixture, neutralized with dilute H 3 P0 4 and then washed with water several times to remove NaCl.
• aqueous potassium hydroxide 2 eq. caustic to 1 eq. chlorine
• reaction mixture was diluted to 20 per ⁇ cent solid concentration with MEK/toluene solvent mixture, neutralized with C0 2 and then washed with water several times to remove NaCl.
• reaction mixture was diluted to 20 per ⁇ cent solid concentration with MEK/toluene solvent mixture, neutralized with C0 2 and then washed with water several times to remove NaCl.

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• 1985
  • 1985-11-08 CN CN85108970.4A patent/CN1004356B/zh 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/ko not_active IP Right Cessation
  • 1985-11-12 BR BR8507064A patent/BR8507064A/pt unknown
  • 1985-11-13 IL IL77036A patent/IL77036A/xx not_active IP Right Cessation
  • 1985-11-18 CA CA000495522A patent/CA1257446A/en not_active Expired
  • 1985-11-18 ES ES548999A patent/ES8701206A1/es not_active Expired
• 1986
  • 1986-07-16 FI FI862961A patent/FI862961A/fi not_active Application Discontinuation
  • 1986-07-18 NO NO862909A patent/NO165078C/no unknown
• 1987
  • 1987-08-25 MY MYPI87001452A patent/MY101828A/en unknown

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Non-Patent Citations (2)

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