DD298648A5 - PROCESS FOR PREPARING POLYFUNCTIONAL EPOXY RESINS BASED ON BISPHENOLES - Google Patents

Abstract

The invention relates to a synthesis process for the preparation of polyfunctional epoxy resins based on bisphenols, the z. B. can be used as a monomer, comonomer, crosslinker or modifier in polymer reactions. According to the invention, a bisphenol is reacted in the presence of a substituted polyoxymethylene with exclusion of oxygen in the temperature range from 180 to 200 ° C. to form alkylene-linked bisphenols. The prepolymers thereby obtained are reacted with a large excess of epichlorohydrin in the presence of a catalyst in a suitable manner, all phenolic hydroxyl groups being reacted by epichlorohydrin to form chlorohydrin ethers. After distilling off the excess epichlorohydrin in vacuo, the solution was taken up in a water-immiscible solvent and dehydrohalogenated in portions with a aqueous, alkaline solution at temperatures preferably between 90 and 115C. From the organic phase, a polyfunctional epoxy resin based on alkylene-linked bisphenols was obtained after purification operations. The viscosity of the epoxy resin can be adjusted by the amount of substituted polyoxymethylene. prepolymers; polyfunctional epoxy resins; bisphenols; epichlorohydrin; substituted polyoxymethylenes; Temperature; Reaktionsfuehrung; inert gas; dehydrohalogenation}

Description

field of use

Temperature-resistant epoxy resin systems are used as encapsulants of microelectronic components, as adhesives, as a coating component, as a base material for reinforced epoxy resin materials and as a system component of photopolymerizable information recording materials.

Characteristic of the prior art

It is known that alkylene-linked bisphenols of the formula VII

(VII)

(R)

can be prepared from the analogous bisphenol, cf. Formula I, H H

(I)

by reaction with Foi malinlösung in the presence of an acidic catalyst. (US 3928288, US 4102 & 66, US 4137220, US 4686248, Res. Disci. 264 [1986] 174)

The reaction is carried out in a solvent. This must be separated after the synthesis, so that the resulting prepolymer can be further processed according to formula IV (US 4680348, US 4551508, US 45297Q0). Other authors also use paraformaldehyde instead of formaldehyde. However, it does not waive a catalyst and a solvent (DE-AS 1570958).

In addition, it is described that it is problematic to substitute virtually quantitatively all epichlorohydrin for all hydroxyl groups in compounds of formula IV (EP 117759), wherein compounds of formula V are to be obtained.

(x

(VIII)

(R)

CH ^ -CH-CH ^ -ClOH

Andare authors produce chlorohydrin compounds according to formula VIII by z. B. Diandichlorhydrinether with formaldehyde in the presence of a catalyst (eg H ₂ SO ₄ ) is reacted in a solvent (JP 61066711). In this case, chlorohydrin compounds are to be formed according to formula VIII. However, diandichlorohydrin ether must first be present for this process. It is furthermore known that epoxide resin precondensates of the diandiglycidyl ether can be prepared by, for example, reacting dian with epichlorohydrin to give the corresponding chlorohydrin and dehydrohalogenating it with alkali to the corresponding epoxide. It is often worked in the presence of a catalyst.

DE-OS (4,614,826) discloses that epoxy resins having a low chlorine and phenolic hydroxyl group content can be prepared by reacting bisphenol A with a large excess of epichlorohydrin in a suitable manner with a catalyst and then reacting with an excess Alkali dehydrohalogenated to the corresponding epoxide. This method mainly refers to substituted bisphenols and some representatives of phenolic novolacs. Novolacs based on bisphenols have not been mentioned. In addition, the said synthesis is not carried out under anaerobic conditions, which often leads to a discoloration of the final products. In an application for information-storing systems thus some parameters such. B. the optical transparency in the visible spectral range greatly reduced in their effectiveness.

2Ie of the invention

The aim of the invention is to produce polyfunctional epoxy resins based on bisphenols.

Explanation of the essence of the invention

The invention has for its object to develop a simple process for the preparation of polyfunctional epoxy resins based on bisphenols.

According to the invention the object is achieved by reacting bisphenols of the formula I,

(D

wherein X can be any substituent, X can mean: -, SOj, 0, arylene, substituted alkylene groups having 1-6 C-atoms, O-alkylene-0,0-arylene-O, wherein R also be an arbitrary substituent R may be: H, alkyl having 1-6 C atoms, but where R may be the same or different, where η may be an integer from 1 to 2, reacted with a substituted polyoxymethylene of the formula II or III with exclusion of oxygen in the temperature range of 180-200 ⁰ C,

-E-

O-CH-4- R ₁ (Ti ₁

(III)

wherein Ri may be H, CH ₃ , and the prepolymer thereby obtained, see formula IV, OH

(IV)

(R)

where (R) _n and X have the same meaning as in formula I, Ri has the same meaning as in the formulas II and III and χ can assume values of 0.2 to 5, is added with an excess of epichlorohydrin in the presence of a known Catalyst, and to the solution thus obtained, a mixture of epichlorohydrin and the same catalyst at temperatures of 35-50 ° C slowly zuttopft, then heated to boiling heat, a certain time at this temperature leads, wherein all phenolic hydroxyl groups are reacted with epichlorohydrin to compounds of the formula V,

OH OCH ₂ -CH-CH ₂ -Cl

(V)

(R)

OCH ₂ -CH-CH ₂ -Cl

OH

wherein (R) _n and X have the same meaning as in formula I, R, the same meaning as in the formulas II and III and χ have the same meaning as in formula IV, then distilling off excess epichlorohydrin in vacuo to give the resulting viscous mass a water-immiscible aromatic solvent is added, which has a boiling point of 80-140 ⁰ C, dehydrohalogenated with the aqueous solution of a base at temperatures of 90-115 ° C, wherein the organic phase is separated, suitably of alkali is washed free and after removal of the excess solvent polyfunctional epoxy resins are obtained according to formula VI.

(Vl)

(R)

where (R) _n and X have the same meaning as in formula I, R) the same meaning as in formula II and III and χ have the same meaning as in formula IV, which depending on the amount of polyoxymethylene used, cf. Formula II or III, have a variable viscosity.

For this synthesis method either an inert gas, preferably argon or nitrogen, or a vacuum with a pressure <2 torr is used to produce a medium which excludes the interfering influence of the oxygen. Surprisingly, it has been found that one can produce polyfunctional epoxy resins based on bisphenols by reacting a substituted bisphenol in the presence of substituted polyoxymethylenes within a certain temperature interval (180-200 ⁰ C) is heated under inert gas. It has been found that preferably in this temperature interval (180-200 ⁰ C) formed within one hour structures of formula IV. An oxygen-free atmosphere at this temperature prevents partial oxidation of the components by atmospheric oxygen. An advantage of this method is also that the obtained novolak according to formula IV is available in a very short time, wherein the purity is sufficient for many purposes. If it is condensed with formalin solution, then after the condensation (this usually takes longer), the excess water of reaction and the solvent must first be distilled off before the resulting product can be further processed according to formula IV.

In addition, traces of the acidic catalyst, which was added in the condensation of bisphenol with formaldehyde, prove to interfere with the further course of the reaction. Since the reaction of the novolak with a large excess of epichlorohydrin occurs in the presence of a catalyst, acidic products (eg, oxalic acid) can also help to make the reaction by epichlorohydrin (which is present in a very large excess) quickly out of control can guess. An example would be z. B. the intrinsic polymerization of epichlorohydrin, which is usually highly exothermic. It also proved to be advantageous to put the novolak of formula IV with a large amount of epichlorohydrin and itoqnm mixture is a mixture of epichlorohydrin and a catalyst at elevated temperature can be (35-50 ⁰ C) is added dropwise. It wuro _, lan, that all phenolic hydroxyl groups of the novolak used according to formula IV react with epichlorohydrin, whereby compounds of formula V are formed almost quantitatively.

In the further reaction, the procedure is that dehydrohalogenated with alkali in the temperature range of 90-11O ⁰ C, washed alkali-free, the solution is dried and excess solvent removed in vacuo. According to the invention polyfunctional epoxy resins are obtained according to this method, which have a variable viscosity depending on the amount of polyoxymethylene used according to formula II or III. The purity of the product obtained is sufficient for many purposes. It should also be emphasized that some performance parameters, such. As the optical transparency in the visible spectral range, according to this method are better, since the reactions are carried out substantially in the absence of air.

embodiments

example 1

100 g of dian and 15 parts of paraformaldehyde are mixed together well and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. A weak stream of inert gas is passed over the mixture and then heated to 18O ⁰ C until a transparent mass is formed. The mixture is then heated for a further 0.5 h at 200 ⁰ C on. After this procedure, the reflux condenser is exchanged for a half-micro distillate and distilled at this temperature excess water of reaction in a water jet pump vacuum. There is obtained a yellow resin with a softening point of about 90 ⁰ C.

 M "= 639g / mol

5 mol of epichlorohydrin are added to the resulting resin at 40 ^° C. and the mixture is stirred until the solution is homogeneous. The resulting solution is filled in a sulfonating flask (equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel) and saturated with argon. For this purpose, a further solution is added dropwise, which consists of 5mol epichlorohydrin and 1.15g triethylbenzylammonium chloride. After 40 minutes, this process must be completed. The reaction mixture thus obtained is then kept boiling for about 6 h. After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360ml toluene, heated to reflux, and within 30 minutes, 98.1 g of 45% NaOH is added. It is allowed to react for 6 hours. After cooling, 400 ml of water are added and washed with a 15% sodium dihydrogen phosphate solution until a pH of 6 is reached. After Abtiennen the aqueous phase is dried with sodium sulfate and excess solvent removed at 40-50 ⁰ C in a rotary evaporator, whereby a pale yellow resin is obtained with a very tough consistency.

Yield: 85%

Epoxy equivalent: 222

M _n = 1360g / mol

Example 2

100 g of dian and 10 parts of paraformaldehyde are well mixed together and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. Passing a weak inert gas stream over the mixture and then heated to 185 ⁰ C until a transparent mass is formed. The mixture is then heated for a further 0.5 h at 200 ⁰ C on. After this procedure, the reflux condenser is exchanged for a half-micro-still and distilled at this temperature excess water of reaction in a water jet pump vacuum. There is obtained a yellow resin with a softening point of about 90 ⁰ C.

M _n = 524g / mol

5 mol of epichlorohydrin are added to the resulting resin at 40 ° C. and the mixture is stirred until the solution is homogeneous. The resulting solution is filled in a sulfonating flask (equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel) and saturated with argon. For this purpose, a further solution is added dropwise, which consists of 5mol epichlorohydrin and 1.15g triethylbenzylammonium chloride. After 40min this process must

to be finished. The reaction mixture thus obtained is then kept boiling for about 6 h. After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360ml toluene, heated to reflux, and within 30 minutes 98.1 g of 45% NaOH are added. It is allowed to react for 6 hours. After cooling, 400 ml of water are added and washed with a 15% sodium dihydrogen phosphate solution until a pH of 6 is reached. After separating the aqueous phase is dried with sodium sulfate and excess solvent removed at 4Q-50 ° C in a rotary evaporator, whereby a pale yellow resin is obtained with a very tough consistency.

Yield: 85%

Epoxy equivalent: 224

M "= 710 g / mol

Example 3

100 g of dian and 5 parts of paraformaldehyde are mixed together well and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. Passing a weak stream of inert gas over the mixture and then heated to 200 "C until a transparent mass has formed. Then, further heated at 200 ⁰ C for about 0.5 hours. After this procedure, the reflux condenser is replaced with a Halbmikrodestille and you At this temperature, excess reaction water is distilled off in a water jet pump vacuum, giving a yellow resin having a softening point of about 65 ^° C.

 Mn = 324g / mol

To the resulting resin 5 mol of epichlorohydrin are added at 4O ⁰ C and stirred until the solution is homogeneous. The resulting solution is filled in a sulfonating flask (equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel) and saturated with argon. For this purpose, a further solution is added dropwise, which consists of 5mol epichlorohydrin and 1.15g triethylbenzylammonium chloride. After 40 minutes, this process must be completed. The reaction mixture thus obtained is then kept boiling for about 6 hours. After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360ml toluene, heated to reflux, and within 30 minutes, 8.1 pounds of 45% NaOH is added. The mixture is allowed to react for a further 6 hours under these conditions. After cooling, 400 ml of water are added and washed with a 15% sodium dihydrogen phosphate solution until a pH of 6 is reached. After separating the aqueous phase is dried with sodium sulfate and excess solvent removed at 40-50 ⁰ C in a rotary evaporator, whereby a nearly colorless resin is obtained, which has a viscosity similar to that of the glycerol.

Yield: 85%

Epoxy equivalent: 224

M "= 524g / mol

Example 4

100 g of dian and 5 parts of paraformaldehyde are well mixed together and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. A vacuum of less than 1.5 torr is applied to this apparatus. Then it is heated to 200 ⁰ C until a transparent. Mass is formed. It is still heated at 200 ⁰ C for about 0.6 h. After this procedure, the apparatus is depressurized and the reflux condenser exchanged for a half-micro distillate and distilled at this temperature which is greater than 175 ⁰ C excess reaction water in a water pump vacuum. It is a yellow resin with a softening point of about 05 ⁰ C obtained. M _n = 392g / mol

To the resulting resin 5 mol of epichlorohydrin are added at 4O ⁰ C and stirred until the solution is homogeneous. The resulting solution is filled in a sulfonating flask (equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel). Again, a vacuum of less than 1.5 torr is applied to this apparatus. For this purpose, another solution (this was previously also evacuated to a pressure <2 Torr), which consists of 5mol epichlorohydrin and 1.15g Triethyibenzylammoniumchlorid. After 40 minutes, this process must be completed. The reaction mixture thus obtained is then kept boiling for about 6 hours and then relaxed.

After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360 ml toluene, purged with argon, heated to reflux, and within 30 min 98.1 g of 45% NaOH are added. The mixture is allowed to react for a further 6 hours under these conditions. After cooling, 400 ml of water are added and washed with a 15% sodium dihydrogen phosphate solution until a pH of 6 is reached. After separating the aqueous phase is dried with sodium sulfate and excess solvent removed at 40-5O ⁰ C in a rotary evaporator, whereby a pale yellow resin is obtained, which has a viscosity similar to that of the glycerol.

Yield: 85%

Epoxide equivalent: 224

M _n = 524g / mol

Example 5

100 g of 4,4'-dihydroxydiphenylsulfone and 10 parts of paraformaldehyde are mixed together well and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. Passing a weak inert gas stream (argon) over the mixture and then heated to 200 ⁰ C until a polymeric mass is formed. Then it is heated for about 0.95h at 200 ° C on. After this procedure, the reflux condenser is replaced with a semi-microdrop and at this temperature, excess water of reaction is distilled in a water-jet pump vacuum. It will receive a resinous mass

M _n = 362g / mol

To the obtained resin are added epichlorohydrin at 4O ⁰ C Smol. The resulting solution is stirred well until a fine suspension is obtained. The solution thus obtained is in a sulfite rkolben (this is equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel) filled and filled with argon. For this purpose, a further solution is added dropwise, which consists of 5mol epichlorohydrin and 1.15g triethylbenzylammonium chloride. After 40 minutes, this process must be completed. The reaction mixture thus obtained is then kept boiling for about 6 hours. After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360ml toluene, heated to reflux, and within 30 min, 98.1 g of 45% NaOH is added. It must be stirred well, since a white solid precipitates. The mixture is allowed to react for a further 4 hours under these conditions. After cooling, the solid is filtered off with suction, washed with 800 ml of water and washed with a 15% sodium dihydrogen phosphate solution until a pH of 6 has been reached in the washing water. After this process, it is washed again with 400 ml of water. It is obtained a v / eißer solid.

Yield: 95%

Epoxy equivalent: 246

M _n = 563g / mol

Examples

100 g of dian and 1 part of paraformaldehyde are mixed together well and placed in a two-necked flask equipped with a reflux condenser and gas inlet tube. A weak inert gas stream is passed over the mixture and then heated to 220 ° C. until a transparent mass has formed. The mixture is then heated for a further 1 h at this temperature. After this procedure, the reflux condenser is exchanged for a half-micro distillate and distilled at this temperature excess water of reaction in a water jet pump vacuum. There is obtained a yellow resin with a softening point of about 113 ⁰ C.

 M "= 332g / mol

5 mol of epichlorohydrin are added to the resulting resin at 40 ° C. and the mixture is stirred until the solution is homogeneous. The resulting solution is filled in a sulfonating flask (equipped with a stirrer, thermometer, reflux condenser, gas inlet tube and dropping funnel) and saturated with argon. For this purpose, a further solution is added dropwise, which consists of 5mol epichlorohydrin and 1.15g triethylbenzylammonium chloride. After 40 minutes, this process must be completed. The reaction mixture thus obtained is then kept boiling for about 6 hours. After this time, excess epichlorohydrin is distilled off to a bottom temperature of 125 ⁰ C. The resulting resin is taken up in 360ml toluene, heated to reflux, and within 30 minutes 98.1 g of 45% NaOH are added. The mixture is allowed to react for a further 6 hours under these conditions. After cooling, 400 ml of water are added and the mixture is washed with a 15% sodium dihydrogenphosphate solution until a pH of 6 is reached. After separating the aqueous phase is dried with sodium sulfate and excess solvent removed at 40-5O ⁰ C in a rotary evaporator, whereby a nearly colorless resin is obtained.

Yield: 85%

Epoxy equivalent: 27.4

M _n = 524g / mol

-J-

f 0-CH4 II

O-CH

III

-40

JSS MS

(X> 0)

(R)

OH

QH ₉ -CH-CH ₉ -Cl 0

(x> 0)

(R)

CHjCH-CHgCl OH

-AV

MS MS

Ti

(X> 0)

(R)

OH ₀ -CH-CH

YL

Claims (1)

claims: 1. A process for the preparation of polyfunctional epoxy resins based on bisphenols, characterized in that bisphenols of the formula I, (D where X can be any substituent, X can mean: -, SO ₂ , 0, arylene, substituted alkylene groups having 1-6 C atoms, O-alkyltm-0,0-arylene-O, wherein R is also an arbitrary substituent R may be H, alkyl of 1-6 C atoms, but R may be the same or different, where η may be an integer from 1 to 2, reacted with a substituted polyoxyethylene Formula Il or Ill with exclusion of oxygen in the temperature interval of 180-200 ⁰ C, (ID, (III) where R ₁ can be H, CH ₃ , and the prepolymer obtained thereby, compare formula IV, OH -S: (x> 0) (IV) (R) where (R) _n and X have the same meaning as in formula I, R _{1 has} the same meaning as in the formulas II and III and χ can assume values of 0.2 to 5, is treated with an excess of epichlorohydrin in the presence of a known catalyst, and added dropwise to the resulting solution, a mixture of epichlorohydrin and the same catalyst at temperatures of 35-5O ⁰ C slowly, then heated to boiling heat, stirred for a while at this temperature, wherein all phenolic hydroxyl groups are reacted with epichlorohydrin to compounds of the formula V, OH
I
OCHO-CH-CHO Cl (V) (R) where (R) _n and X have the same meaning as in formula I, R _{1 has} the same meaning as in the formulas II and III and χ the same meaning as in formula IV, then distilling off excess epichlorohydrin in vacuo to give the resulting viscous mass a water-immiscible aromatic solvent is added, which has a boiling point of 80-140 ⁰ C, dehydrohalogenated with the aqueous solution of a base at temperatures of 90-115 ° C, wherein the organic phase is separated, suitably of alkali is washed freely and after removal of the excess solvent poiyfunktionelie epoxy resins are obtained according to formula VI, O / \ OCH ₂ -CH-CH ₂ (Vl) (R) wherein (R) _n and X have the same meaning as in formula I, R _{1 has} the same meaning as in formula II and III and χ the same meaning as in formula IV, which depending on the amount of polyoxymethylene used, cf. Formula II or III, have a variable viscosity. 2. The method according to claim 1, characterized in that for this synthesis method either an inert gas, preferably argon or nitrogen, or a vacuum with a pressure <2 Torr is used to exclude the disturbing influence of oxygen. For this 3-page formulas