MXPA00004902A

MXPA00004902A - Phenol-novolacs with improved optical properties

Info

Publication number: MXPA00004902A
Application number: MXPA/A/2000/004902A
Authority: MX
Inventors: H Gerber Arthur
Original assignee: Borden Chemical Inc
Priority date: 1998-09-22
Filing date: 2000-05-19
Publication date: 2001-07-03

Abstract

The specification discloses a method for the manufacture of a fluorescent polyphenolic product with high UV absorbance, its subsequent epoxidation as well as polyphenolic products and epoxidized derivatives and compositions thereof. The polyphenolic products are prepared by heating glyoxal at a temperature of about 80°C to about 100°C with a molar excess of a phenol in the presence of an acidic catalyst which is eliminated from the reaction mixture at a temperature about 170°C. The total mole ratio of glyoxal to phenol charged to the reaction mixture is about 0.15 to 0.22 moles of glyoxal for each mole of phenol. The glyoxal is added continuously or by stepwise additions to the phenol so as to keep the aldehyde units in the reaction mixture to less than about 70%of the aldehyde units in the total quantity of glyoxal to be charged for making the polyphenol. Water is distilled stepwise or continuously from the reaction mixture. The catalyst is removed from the reaction mixture by further distilling the reaction mixture, generally at higher temperatures.

Description

FENOL-NOVOLACS WITH IMPROVED OPTICAL PROPERTIES This invention relates to phenolic glyoxal condensates, glycidylated derivatives thereof, compositions having the condensates and their glycidylated derivatives, as well as methods for the manufacture of the above. In the methods for making the condensates of this invention, a molar excess of phenol reacts with glyoxal at a temperature of about 80 ° C to 100 ° C using an acid catalyst that can be removed from the reaction mixture by distillation to a temperature below about 170 ° C. The reaction is carried out by adding continuously or at least twice glyoxal to a phenol where the total molar ratio between all additions of glyoxal and phenol is about 0.15 to 0.22. The water in the reaction mixture is removed incrementally by distillation during the reaction. Less than about 70% of the total glyoxal that must react with the phenol is added to the reaction mixture at any given time. Likewise, less than about 70% of the total aldehyde units to be supplied to the reaction mixture together with any ketone unit formed in the reaction are present in the reaction mixture at any given time. Each glyoxal molecule contains two aldehyde units. One way to measure the aldehyde units together with the possible ketone units formed is by the determination of aldehyde equivalents, as defined below. The aldehyde equivalents in the reaction mixture are maintained at a level of less than about 70% of the aldehyde equivalents in the total amount of the glyoxal to be charged to the reaction mixture to prepare the condensation product. The catalyst is removed from the reaction mixture when at least about 85% of the aldehyde equivalents or aldehyde units in the total amount of glyoxal have been charged to the reaction mixture to make the condensation product reacted. The removal of the catalyst also removes all the water a part of the water in the reaction mixture. After the reaction of approximately 85% of said aldehyde equivalents and before the removal of the catalyst, in cases in which the trichloroacetic acid is the catalyst, a sufficient amount of basic material is added to the reaction mixture to neutralize HCl to be released by trichloroacetic acid. After removal of the catalyst, the reaction mixture is heated to a temperature of about 175 ° C to 200 ° C for about 0.25 hours to 3 hours. Likewise, after the removal of the catalyst, the remaining unreacted phenol as well as the water will remove temperatures higher than those used to remove the catalyst. BACKGROUND AND PREVIOUS TECHNIQUE Polyphenols, such as polyphenols prepared from glyoxal condensation and a molar excess of phenol in the presence of an acid catalyst, are useful in the same way as other polyphenols and particularly for the preparation of epoxidized polyphenols which they can be used for coating and electronic applications as well as adhesives and laminates in the production of printed circuit boards. The polyphenols of this invention will typically contain from about 1% to about 6% of the ethane tetraphenols. When phenol is phenol itself, tetraphenol is tetrakis (p-hydroxyphenyl) ethane which is also known as TPE. Even when the reaction products of the phenol-glyoxal reaction are mixtures, individual polyphenols such as TPE as well as other components thereof can be crystallized and removed from the solution by conventional techniques. Thus, the level of tetraphenol ethane, such as TPE, in the phenol-glyoxal condensation products, can be greatly reduced to essentially zero by methods well known in the art without sacrificing the desirable optical properties provided by this invention. Illustratively, the use of solvents such as mixtures of alcohol-aromatic hydrocarbon and ketone mixtures miscible in water and water are effective for this purpose. The compositions of this invention are especially useful when an automatic optical inspection (AOI) is used to control the quality of the laminates. The polyphenols of this invention alone, either mixed with phenolic novolacs, or after epoxidation of the polyphenols, are useful for AOI as are epoxy resin adducts and phenolic glyoxal condensate adducts epoxidized with phenolic novolacs. The AOI is typically carried out by measuring the following characteristics: fluorescence at wavelengths within a range of about 450 nm (nanometers) to about 650 nm, particularly at an excitation wavelength of about 442 nm; and / or ultraviolet light absorbency (UV) at wavelengths from about 350 to 365 nm. The applicant has found a set of process conditions together with monomers and certain catalysts to obtain polyphenols and epoxidized derivatives thereof having a UV absorbance and / or fluorescence that is substantially higher than the phenol-glyoxal condensates prepared by others. methods within the range of wavelengths generally used for AOI quality control. Materials that produce a photoimage in combination with these condensates are used. It is desirable to obtain high UV absorbency for the manufacture of laminates used in electronic applications such as high density multi-layer printed circuit boards. The advantages of this invention include: (a) the preparation of a polyphenol essentially free of metal ion if resorting to catalyst filtration or neutralization of washing steps with water where the recovery of phenol is simplified and the yield of the reactor is increased in the cases in which the catalyst is not neutralized with the metal ion; (b) the preparation of polyphenols as well as the epoxidized derivatives thereof having improved optical properties, for example, high fluorescence and / or UV absorbance at the wavelengths employed for AOI; (c) preparation of polyphenols with increased solubility in organic solvents. The prior art discloses many methods for preparing polyphenols as well as epoxidized derivatives thereof. But the prior art does not employ the combination of monomers, reaction conditions, or catalysts that the applicant employs to obtain the desirable properties of the products of this invention. Likewise, the prior art does not disclose phenol-glyoxal condensates having the desirable optical properties of this invention. As used herein, the following terms have the following meanings: (a) "phenol-glyoxal condensation product" refers to the products of the phenol-glyoxal reaction produced by the method of this invention wherein said condensate contains less than % unreacted phenol, preferably less than 3% unreacted phenol, and particularly less than 1.5% unreacted phenol. (b) "aldehyde equivalents" is a method for measuring the aldehyde units and will refer to aldehyde and possibly ketone units that can be formed in the reaction mixture or glyoxal loaded or charged when measured in accordance with the method described later. Such measurements are generally reported as a percentage of equivalents of aldehyde that reacts in comparison with the aldehyde equivalents charged or charged to the reaction mixture. Thus, if measurements of aldehyde equivalents in a mixture of glyoxal and charged phenol show X equivalents of aldehyde and measurements after the reaction in the reaction mixture then show aldehyde equivalents of 1/2 of X, then the equivalents of aldehyde in the reaction mixture are 50% of what was charged. During the reaction, some ketone groups may also be formed which are included in the measurement of the aldehyde equivalents and are considered as part of the aldehyde equivalents herein. The method for determining the aldehyde equivalents is by taking 1.0 g of the reaction mixture and diluting with 50 ml of methanol. The pH is then adjusted to 3.5 with dilute sodium hydroxide. Then, at the pH of the adjusted sample, 25 ml of hydroxylamine hydrochloride are added with stirring. The sample is stirred for 10 minutes and then the sample is re-titrated with 0.25 Normal sodium hydroxide (N) at a pH of 3.5. The number of milliliters (mis) (the title) of the sodium hydroxide solution used to retrotitulate the sample to a pH of 3.5 is used to calculate the aldehyde equivalents. The milliliters of hydroxide solution of sodium in the title are adjusted by correcting by titration with sodium hydroxide for the methanol and hydroxylamine hydrochloride reagents used in the test and this is known as the target of mis. The aldehyde equivalents for the sample are then determined by the following formula: (2.9 times 0.25 N times (milliliters of sodium hydroxide titre minus milliliters of sodium hydroxide in the white grinding). of this formula is then compared with the aldehyde equivalents obtained by the above method and formula based on one gram of a non-heated mixture free of phenol and glyoxal catalyst in the weight ratio between glyoxal and phenol used up to the level in question with the purpose of determining the percentage of aldehyde equivalent that reacted, unless otherwise indicated, the fluorescence measurements here are like the maximum counts per second for a 0.05% solution of the material in question dissolved in tetrahydrofuran (THF) at an excitation wavelength of 442 nm for a one-second acquisition time with an instrument CM 1000 when measured within the range of approximately 450 to 650 nm. CM 1000 refers to Cure Monitor 1000 which is an instrument manufactured by Spectra Group Ltd., Inc. De Maumee, Ohio. The acquisition time is the exposure time at the designated wavelength. A door is a basic unit used by a large number of light measuring devices for data output and refers to a process of accumulated signal digitization. In the case of a CCD detector from Spectra Group Limited, Inc. of Maumee, Ohio, and which was employed for the data presented below, the light produces an electrical charge on the detector that is frequently read by a digitizer. The digitizer is set to record a count approximately every 10 units of charge (electrons) it reads.

The fluorescence measurements are established on a comparative basis between the various materials as in each of the tables presented below and not as absolute numbers. Thus, the polyphenol fluorescence values within any of the tables presented below refer to other polyphenols within the same table but the comparisons can not be made with the same polyphenol or with other polyphenols in other tables. The UV absorbance values are obtained from samples prepared by dissolving the material in question in THF (tetrahydrofuran) at a concentration of 10 mg (milligrams) per 100 ml (milliliters) and the absorbance measurement is carried out at 350 nm or 365 nm. SUMMARY OF THE INVENTION In one aspect, this invention focuses on a method for preparing a polyphenolic product by incrementally contacting and reacting glyoxal with a molar excess of phenol in the presence of an acid catalyst that can be removed from the mixing the reaction by distillation at temperatures below about 170 ° C. A reaction temperature of about 80 ° C to about 100 ° C is employed for the reaction. Water is removed incrementally from the reaction mixture by distillation, while the equivalents of aldehydes in the reaction mixture are maintained at a level less than about 70% based on the aldehyde equivalents of the total amount of aldehyde to load the reaction mixture to make the polyphenol. The molar ratio of the glyoxal charged to the reaction mixture is from about 0.15 to about 0.22 moles of glyoxal for each mole of phenol. The reaction is terminated by distillation to remove the catalyst when at least about 85% equivalents of aldehyde in the total amount of glyoxal has been charged to produce the condensation product reacted. When the catalyst is trichloroacetic acid, a basic material is added to the reaction mixture before the removal of the catalyst to neutralize any hydrochloric acid that could be released during the catalyst removal. The removal of the catalyst also removes a part of the water or all of the water in the reaction mixture. After removal of the catalyst: (a) free or unreacted phenol is removed by distillation from the reaction mixture such that the product is free of catalyst and contains less than about 5% phenol; and (b) the reaction mixture is heated to a temperature of about more than 175 ° C to about 200 ° C for 0.25 to 3 hours. In another aspect, this invention is directed to a method for preparing a polyphenolic product comprising: charging and reacting phenol, and from about 0.06 to 0.11 moles of a 40% glyoxal solution in water in the presence of about 2 to 5% of oxalic acid, the moles of glyoxal are based on the moles of phenol charged; distilling the reaction mixture a first time to remove from about 8% to 12% of the distillate after about 1 to 5 hours of reaction time; load another 0.06 to 0.11 mol of glyoxal based on phenol loaded in such a way that the total amount of glyoxal charged is within a range of approximately 0.15 to 0.22 mol per mol of phenol; continue the reaction for about 1 to 5 additional hours from the time of the start of the first distillation, and distill the reaction mixture a second time to recover approximately 6 to 12% distillate; and continuing the reaction until they have reacted to less than about 85% of the aldehyde equivalents in the total amount of glyoxal to be charged to prepare the condensation product. The aforementioned temperature of the reaction of phenol with glyoxal including the distillations, is from 80 ° C to 100aC. After the reaction of at least about 85% of the aldehyde equivalents in accordance with what was discussed above, the temperature is high and the reaction mixture is distilled at a temperature in the range of about 130 ° C to about 170 ° C to remove catalyst and water. The unreacted phenol remaining after the catalyst removal is removed by distillation at temperatures higher than those used to remove the catalyst so that the free phenol in the polyphenol condensate does not represent more than about 5% and the mixture of the The reaction is heated under vacuum to a temperature of about 175 ° C to 200 ° C for about 0.25 to 3 hours to produce the phenol-glyoxal condensation product. In a further aspect, this invention focuses on a method for preparing epoxy resins in the form of glycidyl ethers of the polyphenols described above by epoxidation of the polyphenol with a halohydrin in the presence of an alkali metal hydroxide, such as, for example, hydroxide. of sodium. In a further aspect, this invention focuses on a method for the preparation of epoxy resins by reacting the phenol-glyoxal condensation product with a preformed epoxy resin to prepare epoxy resin derivatives of the phenol-glyoxal condensation products. • In other aspects, this invention focuses on polyphenols prepared by the methods of this invention and epoxidized products prepared therefrom. In additional aspects, this invention is directed to compositions containing the phenol-glyoxal condensation products or epoxidized derivatives thereof and to compositions with other phenolic novolacs and / or epoxidized derivatives thereof. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph showing the fluorescence spectrum of various epoxidized products. The letter "A" indicates the curve of fluorescence spectra EPON 1031 (CAS: 7328-97-4) which is a commercial epoxy resin of a polyphenol having less than 1% free phenol commercially used for AOI fluorescence in the same lengths of wave that are illustrated in the graph. EPON 1031 is sold by Shell Chemical Co. Letter B "indicates the fluorescence spectrum curve of the epoxidized product of example 5a of this application where the epoxidized product is produced by the same method as that illustrated in example 8. The letter? "C" indicates the fluorescence spectrum of the epoxide product of example 8. It can be seen from figure 1 of the drawing that the polyglycidyl ether of the phenol-glyoxal condensation products of this invention have an unexpectedly higher fluorescence than an excitation wavelength of 442 for an acquisition time of one second when measured within the range of 450 to 650 nm compared to the commercial product EPON 1031 as well as the polyglycidyl ether of the product of example 5a.

DETAILED DESCRIPTION OF THE INVENTION The phenolic monomer The phenolic monomer, also known simply as phenol, is a phenol which can be unsubstituted or substituted, for example, with alkyl, phenyl or alkoxy groups. Typical phenolic monomers are mononuclear or binuclear monohydroxyphenols that have at least one ortho or para position available for linkage. The phenolic monomer typically has up to about 12 carbon atoms and preferably up to about carbon atoms. Such compounds include two phenol points themselves; alpha-naphthol; phenylphenol; cresols, for example, 2-methylphenol and 3-methylphenol; various xylene, for example, 2,5-dimethylphenol and 3,5-dimethylphenol; and other alkyl phenols; and alkoxyphenols such as 2-methoxyphenol or 3-methoxyphenol. Mixtures of phenolic compounds can be used. A preferred phenolic compound is unsubstituted phenol, ie, phenol itself. Preferred phenolic monomers can be represented by the following formula: where R 'is selected from phenyl, alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms and y is an integer of Oa 3. When R' is alkyl or alkoxy, and is 1 to 3, and when R 'is phenyl and is 1. Mixtures of phenolic monomers can also be used. The glyoxal reagent The glyoxal reagent can be found in various forms such as for example relatively pure monomeric glyoxal, polymerized glyoxal or glyoxal dissolved in water and mixtures thereof. Illustratively, glyoxal is normally used in the form of a 40% water solution. The acid catalyst The acid catalyst is a catalyst that can be removed from the reaction mixture by distillation in the reaction mixture at a temperature above about 80 ° C, but below about 170 ° C and preferably below of approximately 160 ° C. Illustratively, the catalyst may be oxalic acid or a trihaloacetic acid or mixtures thereof. In the case of oxalic acid as catalyst, the temperature of the reaction mixture rises above about 130 ° C to about 170 ° C together with distillation, and preferably the temperature rises to about 140 ° C to about 160 ° C. in such a manner that the oxalic acid catalyst decomposes into volatile components. Oxalic acid can be used in its various forms as for example the pure compound, the dihydrate or, mixtures thereof, all of which are known as oxalic acid here. Illustrative examples of trihaloacetic acid catalyst which may be mentioned are: trichloroacetic acid and trifluoroacetic acid. The trifluoroacetic acid may require to be refilled during the reaction since a portion thereof is distilled together with the water. The trifluoroacetic acid forms an azeotropic mixture in water. Accordingly, when it is desired to remove the trifluoroacetic acid catalyst, it is preferable that a series of distillations with addition of water be made after each distillation in order to remove substantially all of the acid. When trichloroacetic acid is used as a catalyst, the temperature is raised to about 170 ° C to remove the catalyst after neutralization of any possible formation of hydrochloric acid from trichloroacetic acid. The amount of catalyst can vary from about 1% to about 6% based on the weight of the phenol charged to the reaction mixture. The amount of oxalic acid is from about 1% to 6%, preferably from about 1.5% to about 5% and particularly from about 2.5% to about 4% based on the weight of the phenol charged to the reaction mixture. When trihaloacetic acid is used as catalyst, the amount of catalyst is preferably from about 1% to about 4% by weight based on the phenol charged to the reaction mixture and particularly from about 1% to about 3%. Mixtures of the acid catalysts can also be used. Reaction conditions The polyphenols (condensation products) of this invention can be prepared by continuous or stepwise contacting of the glyoxal in a molar excess of the phenol in the presence of an acid catalyst. Illustratively, in the case of the step reaction, a phenol and the acid catalyst are charged to a reactor and then an initial increase of the trioxal is charged to the reactor while maintaining the reaction mixture at a temperature of about 80 ° C to about 100 ° C. The glyoxal reacts with the phenol and then additional glyoxal is added to the reaction mixture. The molar ratio between the glyoxal and the phenol in the manufacture of the phenol-glyoxal condensation products is from about 0.15 to 0.22 mol of glyoxal for each mol of charged phenol and is preferably from about 0.16 to 0.22 mol of glyoxal for each mol of phenol loaded. When a total of the glyoxal increments are made to the reaction mixture, it is preferred that each increment be from about 0.06 to 0.11 mol of glyoxal based on the total moles of phenol charged and particularly be about 2 equimolar amounts of glyoxal. Total molar ratios less than about 0.15 mol of glyoxal per mole of wired phenol provide more tetraphenols, such as for example TPE that is essentially free of optical properties in the ranges given above for quality control of AOI. Relationships greater than about 0.22 mol of glyoxal for each mol of phenol cause longer reaction times and it is likely that a product with higher viscosity will be obtained in this way. The aldehyde equivalents or aldehyde units in the reaction mixture are maintained at less than about 70%, and preferably less than about 60% of the total aldehyde equivalents or total aldehyde units that will be charged to the mixture of the reaction to prepare the phenol-glyoxal condensate. Thus, no more than about 70% of the aldehyde equivalents to be employed in the reaction are present in the reaction mixture at any given time. The catalyst of the reaction mixture that at least about 85% of the aldehyde equivalents of the total equivalents of aldehyde to be charged to the reactor have reacted, and preferably when they have reacted from about 90% to 95% of such equivalents of aldehyde. Then, the temperature is generally increased to remove the catalyst. However, when the trichloroacetic acid is the catalyst, a basic material is added to the reaction mixture in an amount sufficient to neutralize any hydrochloric acid that could be formed as a decomposition product of said acid before carrying out the distillation to remove the catalyst. When the basic material used to neutralize the hydrochloric acid is an alkali metal oxide or alkali metal hydroxide or an alkali metal oxide or hydroxide, for example, sodium hydroxide or calcium hydroxide, approximately 80% equivalents are added molars of such bases, based on the molar equivalents of trichloroacetic acid used as a catalyst. When an amine is used as the basic material, from about 10% to 20% molar equivalents of amine are added to the reaction mixture to neutralize HCl based on the molar equivalents of trichloroacetic acid used as a catalyst. It is preferred that the basic material be an amine such that metal ions such as alkali metal or alkaline earth metal ions are not included in the product. The presence of metal ions is negative for the use of the product in electronic applications that require higher quality. Illustrative examples of amines for neutralizing the hydrochloric acid which may be mentioned are amines having a pKa value of from about 5 to about 11 such as for example pyridine, picoline, benzyldimethylamine, triethylamine, as well as hydroxyethyldiethylamine. The total time for the condensation reaction of aldehyde with the phenol will typically vary from about 5 to about 15 hours and preferably from about 8 to 12 hours. The temperature of the condensation reaction of phenol and glyoxal in the presence of the catalyst, including distillations, will be located within a range of about 80 ° C to about 100 ° C and preferably from about 85 ° C to about 95 ° C until at least about 85% or more of the aldehyde equivalents in the amount total glyoxal to charge to prepare the condensation product have reacted. Water is removed continuously or intermittently by distillation, as for example, after the reaction of glyoxal with phenol after individual additions of the glyoxal, since the reaction decreases upon accumulation of the water in the reaction mixture. Water is formed by the condensation reaction of glyoxal with phenol and in addition water is generally present in the glyoxal loading as for example glyoxal is generally employed in the form of a 40% solution in water. The water content in the reaction mixture is preferably maintained at a level below about 8% by weight based on the phenol charged to the reaction mixture and preferably below about 6% based on the weight of the phenol charged to the reaction mixture. Illustratively, two or more, for example from 2 to 4, glyoxal additions are made to the reaction mixture with water distillation after the reaction of the glyoxal with the excess phenol. Preferably, an initial charge of glyoxal is carried out with the subsequent reaction followed by distillation of water and then a second charge of glyoxal is carried out followed by reaction of the monomers before the reaction of at least about 85% of the equivalents Total aldehyde to be used to produce the condensation product. Instead of monitoring the progress of the reaction by measuring aldehyde equivalents, the reaction time can be used to carry out the reaction when the reagents and catalysts are the same and when the operating conditions are within the limits of the reaction. Same ranges, for example, molar ratios, reaction temperatures, catalyst and amount thereof; times for distillation of water and the amount of distillate. Illustratively, the following steps and periods may be employed when: the total molar ratio between glyoxal and phenol is from about 0.15 to 0.22; a 40% solution of glyoxal reacts with phenol itself at a temperature of 80 ° C to 100 ° C; an initial charge of glyoxal is carried out with subsequent reaction of the glyoxal with phenol and in time by distillation, followed by another addition of glyoxal followed by a continuous reaction and then distillation which is followed by a continuous reaction before the depletion of the aldehyde equivalents at 15 % or less of the load. From approximately 0.06 to 0.11 mol of glyoxal, based on the amount of phenol loaded, they are used with each glyoxal load. Thus, after the addition of the initial amount of glyoxal, the aldehyde reacts with the phenol for about 1 to 5 hours, preferably 1.5 to 3 hours and then distils from about 8% to 12% of a first distillate from the reaction mixture based on the weight of charged phenol. After the first distillation, which is also carried out within the temperature range of about 80 to 100 ° C, slowly add to the reaction mixture 0.06 to 0.11 mol of glyoxal based on the charged phenol moles. Preferably, approximately equal amounts of glyoxal are charged during each addition. Heating of the reaction mixture proceeds for an additional 1 to 6 hours, preferably for an additional 1.5 to 5 hours from the ignition time of the first distillation and after a second distillation is started to remove approximately another 4 to 12% Water based on phenol loaded. After the second distillation, the reaction is allowed to proceed for another 0.5 to 6 additional hours, preferably 1 to 4 additional hours from the time of the second distillation start before the temperature rise for distillation together with removal of the catalyst. The temperature of 80 ° C to 100 ° C is used until it is time to raise the temperature and remove the unreacted catalyst or phenol. Such distillation before raising the temperature to remove the catalyst is carried out in vacuum in order to help control the temperature. Vacuum can vary from approximately 15 to 25 inches or more of mercury. The temperature for the removal of the catalyst by distillation is less than about 170 ° C, preferably less than about 160 ° C. When the oxalic acid is the catalyst, the temperature is raised to a level greater than 135 ° C to about 170 ° C, particularly from about 155 ° C to about 160 ° C. The entire water or a part of the water is removed at the time of removal of the catalyst. In the case where the catalyst is oxalic acid, all or substantially all of the water is removed when the catalyst is removed from the reaction mixture. Any water remaining in the reaction mixture after the removal of the catalyst is finally removed by distillation by removing the phenol. After removal of the water and all of the catalyst, the unreacted (free) phenol is removed from the reaction mixture in order to bring the free phenol content of the reaction mixture to a level of less than about 5%, preferably, less than about 2% and particularly less than about 1.5% by weight of the reaction mixture. The removal of the unreacted phenol is achieved by conventional means such as the removal of unreacted phenol in novolac resins such as, for example, flash distillation by heating the reaction mixture to an elevated temperature under vacuum. Thus, the temperature can be up to about 190 ° C or 200 ° C under a pressure of about 25 to 35 inches of mercury. Vacuum vapor addition at such temperatures can also be used to remove phenol in the product. Concurrently with the removal of the phenol or as a separate step after the removal of the catalyst, the reaction mixture is heated to a temperature of about 175 ° C approximately 220 ° C and preferably approximately 180 ° C approximately 195 ° C. Said heating is carried out for a period of about 0.25 to 3 hours and preferably about 0.5 to 2 hours. All or a part of said heating can be carried out at the moment in which the phenol is removed in vacuum. Optionally, the condensation product of phenol-glyoxal with 5% or less of unreacted phenol can be placed in an inert and heated atmosphere to carry out part or all of the heating within the range of about 175 ° C to 20 °. C for approximately 0.5 to 3 hours. Illustrative examples of an inert atmosphere are nitrogen or argon. After said heating step at a temperature of about 175 ° C to 200 ° C and after the reduction of phenol in the reaction mixture to a level of less than 5%, the reaction mixture is also known as the product of phenol-glyoxal condensation. The phenol-glyoxal condensation product is optionally cooled and generally ground, for example, formed into flakes. Preparation of polyepoxides Epoxidized products of this invention can be prepared by at least two different conventional routes. One way is by reacting the phenol-glyoxal condensate product with a halohydrin in the presence of an alkali metal hydroxide to form glycidyl ethers of the polyphenol. Such epoxy products will typically have epoxy equivalents of about 190 to 230 and preferably about 205 to 225. The other way is by reacting a molar excess of a preformed polyfunctional epoxide with the phenol-glyoxal condensation product. Such products epoxidized by the other route will typically have epoxy equivalents of about 140 to 250 and preferably about 160 to 230. In the first route, the polyepoxide is prepared by contacting the phenol-glyoxal condensation product with an excess of epichlorohydrin in the presence of an alkali metal hydroxide, such as for example sodium hydroxide or potassium hydroxide at a temperature within a range of about 50 ° C to about 80 ° C. Optional catalysts such as, for example, quaternary ammonium salts can be used. The reaction can be carried out in the presence of an inert solvent, including alcohols such as for example ethanol, isopropanol, methyl isobutyl ketone (MIBK), toluene, ethers, and mixtures thereof. Another method for the preparation of polyepoxide by the first route is presented in US 4,518,762 of May 21, 1985, Ciba Geigy Corp. Which is incorporated herein by reference in its entirety. In summary, in this process, the polyphenol, preferably the phenol-glyoxal purified product, reacts at a temperature of 40 ° C to 100 ° C in the absence of a specific catalyst for the formation of chlorohydrin ether intermediate, in presence of 2 to 25% by weight, based on the reaction mixture, of one with lower alkanol solvent or lower alkoxyalkanol, with excess epylchlorohydrin based on the hydroxyphenolic value, in the presence of 0.5 to 8% by weight of water, based on the reaction mixture, and with 0.9 1.15 equivalents of solid alkali metal hydroxide per phenolic hydroxyl group to provide the epoxy derivative of the polyphenol and where 0.5% to 8% by weight of water is found in the mixture of the reaction during the entire reaction period, using a solid alkali metal hydroxide in the form of beads of approximately 1 mm in diameter, said loading hydroxide to the reaction mixture in portions or in a constant manner. During a program of gradually increasing addition, and then the epoxy resin novolac is isolated. In the second route for the preparation of the epoxy resins containing the phenol-glyoxal condensation products of this invention, one part by weight of said condensation product reacts with 4 to 8 parts of a polyepoxide at a temperature from about 100 ° C to about 150 ° C using a catalyst, for example, potassium hydroxide, benzyldimethylamine, benzyltrimethylammonium hydroxide, -methylimidazole, and 2,4,6, -tris (dimethylaminomethyl) phenol. Typical catalyst levels of about 0.1% to about 0.6% based on the reaction mass. Typical polyepoxides for reaction with the phenol-glyoxal condensation product are those of diglycidyl ether resins such as, for example, the diglycidyl ether resins of: bisphenol A; bisphenol F; resorcinoi; neopentyl glycol; cyclohexanedimethanol; and mixtures thereof. The condensation products of phenol-. The glyoxal of the present invention can also be partially epoxidized without sacrificing the desirable optical properties by reducing the amount of alkaline products used in the reaction with epichlorohydrin. Illustratively, reducing the caustic aspect to about 40% to 70% of what is found in the methods of the first route described above provides partially epoxidized derivatives. Phenol-glyoxal condensation products The properties of the phenol-glyoxal condensation products are the following Properties Range range Wide preferred Mw / Mn 400-600 / 300-390 440-540 / 320-370 Viscosity, 300-2500 450t1500 Cps at 175 ° C free phenol (%) 0-5 0.03-1.5 Tetraphenol ethane 0-6 1-4 as for example TPE (%) Absorbency of at least 0.400 at least 0.450 UV light at 350nm Particularly > 0.5 Absorbency of at least 0.260 at least 0.275 UV light to 365nm in particular > 0.30 The phenol-glyoxal condensation products contain several compounds, including polyphenols such as diphenols, triphenols, and tetraphenols. Illustratively, such tetraphenols can be represented by the formula: where x is an integer from 0 to 3. When R is alkyl and / or alkoxy x is 1-3, the alkyl and alkoxy groups have from 1 to 4 carbon atoms. When the reactants are phenol itself and glyoxal, the polyphenol above is tetrakis (4-hydroxyphenyl) ethane (TPE) which is also known as 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane. The epoxidation of tetrakis (4-hydroxyphenyl) ethane provides the tetraklycidyl ether of tetrakis (4-hydroxyphenyl) ethane. Unless trichloroacetic acid is used as a catalyst with metal ion oxides or metal ion hydroxides for neutralization of hydrochloric acid, the phenol-glyoxal condensation products of this invention will typically have a percentage by weight concentration of metal ions of less than about : 0.005% for sodium; 0.003% for calcium; 0.003% for iron; and 0.002% for potassium. The polyepoxide products of this invention when employed in electronic applications such as laminates for the production of printed circuits will typically have the following composition based on 100 parts of a conventional epoxy resin such as, for example, an epoxy resin such as diglycidyl ether bisphenol A: (a) from about 18 to 25 parts of phenol-formaldehyde novolac; (b) from 3 to 10 parts of a member selected from the group consisting of a glycidylated phenol-glyoxal condensation product, a reaction product of an epoxy resin and a condensation product of phenol-glyoxal, a condensation product of phenol-glyoxal and mixtures thereof; and (c) optionally, an epoxy curing accelerator. The conventional epoxy resin constituting the 100 parts of the composition is preferably a flame-retardant epoxy resin, such as a halogenated epoxy resin such as, for example, a chlorinated or brominated epoxy resin. Illustrative examples of such brominated epoxy resins that may be mentioned are the brominated product of diglycidyl ether of bisphenol A, for example, EPON 1124 (CAS: 26265-08-07) from Shell Chemical Co. This brominated epoxy resin can be used in flame retardant compositions with epoxy resins such as those of glycidyl ethers of a phenolic / novolac, glycidyl ethers of an o-cresol / formaldehyde novolac, ethers diglycidyl of bisphenol A, diglycidyl ethers of bisphenol F, diglycidyl ethers of resorcinoi, diglycidyl ethers of neopentyl glycol or diglycidyl ethers of cyclohexanedimethanol and mixtures thereof. Epoxy curing accelerators are used in an amount sufficient to accelerate the curing of the epoxy resin. Generally, said amount is from about 0.05 to 0.5 parts based on 100 parts of the basic epoxy resin and particularly about 0.1 to 0.2 parts. Such accelerators include 2-methylimidazole, 2-ethyl-4-methylimidazole, amines such as 2,4,6-tris (dimethylaminomethyl) phenol and benzyldimethylane, as well as organophosphorus compounds such as tributylphosphine and triphenylphosphine. The phenol-glyoxal condensation products of this invention in these with other phenol-novolacs having a UV absorbance of less than 0.260 at 365 nm are useful as curing agents for epoxy resins. Such other phenolic novolacs may comprise from about 50% to 90% of said curing composition and the phenol-glyoxal condensation product comprises from 10 to 50% of said curing composition. From about 15 to 30 parts of this type of curing composition can be used to cure 100 parts of epoxy resin. Illustrative of such other novolacs, there may be mentioned those prepared from formaldehyde and phenol or a substituted phenol as well as mixtures thereof; preparations made from bisphenol A and naphthol as well as substituted polycyclic phenols. Substituents for the monomers include hydroxy, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms as well as phenyl. Preferred resins of other novolacs include phenol-formaldehyde novolacs and ortho-cresol-formaldehyde novolacs having a molecular weight of 1000 to 5000. The average molecular weight (Mw) weight and the average molecular weight number (Mn) here are measured using gel permeation chromatographies and phenolic compounds and polystyrene standards. The molecular weight of the sample to be measured is prepared in the following manner: the sample is dissolved in tetrahydrofuran and the solution is treated through a gel permeation chromatograph. The free phenol in the sample is excluded from the calculation of molecular weight. The amount of TPE in the various reaction mixtures was determined by the following method. (a) The reagents used were para-ethyl phenol, TPE, and silylation reagent. (b) The procedure for determining TPE was as follows: a silylation reagent was prepared in the following manner: in a 25 ml reaction bottle (milliliters), syringe was added: 10 cc (cubic centimeters) of pyridine, 3 cc of trimethylchlorosilane (TMCS), and 10 cc of hexamethyldisilazane (HMDS). It was left to rest for 5 to 10 minutes. (c) The standard solution of TPE is prepared as follows: weigh approximately 30 mg each of TPE and p-ethylphenol in a bottle (suitable for assimilation). Add Ice of silylation reagent. Shake until dissolved (approximately 10 minutes). Heat at low temperature overnight. Inject 1 microliter in gas chromatograph. Use methyl ethyl ketone as rinses. The column used for this analysis is Dexil 300 supplied by Supelco of Belfonte, Pa.

In order that those skilled in the art may more readily understand the invention presented herein, the following examples are offered. All parts and percentages in the examples, as well as elsewhere in this application, are by weight, unless specifically indicated otherwise.

The following examples are illustrative of the invention. Some of the examples are designated as "comparative" to show differences of examples that are part of this invention and not necessarily as comparisons with the prior art. EXAMPLE 1 PREPARATION OF PHENOL-GLIOXAL CONDENSATION PRODUCT AT A TEMPERATURE OF 90 ° C WITH TWO GLIOXAL ADDITIONS TO 1,728 grams (g) (18.36 moles) of phenol and 69.1 g of oxalic acid dihydrate at a temperature of 90 ° C 227 g of 40% glyoxal in water were added for 30 minutes (1.57 moles). The temperature was maintained at 90 ° C for an additional 1.5 hours and then 185 g of distillate (10.7% based on the weight of the charged phenol) of the reaction mixture was distilled in vacuo at 90 ° C for a period of forty minutes. . After said heating, approximately 79% of the aldehyde equivalents charged up to this point had reacted and the amount of water in the reaction mixture was about 4%. An additional 227 g of 40% glyoxal in water (1.57 moles) was added to the reaction mixture over a period of 25 minutes while the temperature was maintained at 90 ° C for 1.5 hours and then 195 g of distillate was distilled in vacuo. (11.3% based on the weight of phenol loaded) at a temperature of 90 ° C for a period of thirty minutes. After said heating, approximately 70% of the aldehyde equivalents charged up to this point had reacted and the water content of the reaction mixture was about 3.5%. The molar ratio between glyoxal and phenol for the total of both glyoxal additions was 0.17. The temperature of 90 ° C was maintained for an additional 1.5 hours. After said heating, 90% of the aldehyde equivalents charged to the reaction mixture until now had reacted and the water content was about 4.5%. Then the reaction mixture was distilled at atmospheric pressure at 160 ° C and maintained at 160 ° C for 1 hour. The reaction mixture was then distilled in vacuo to remove most of the unreacted phenol at 155-160 ° C. The vacuum distillation proceeded to a temperature of 190 ° C and was maintained at this temperature for 1 hour until the phenol in the reaction mixture was less than 1%. The resulting phenol-glyoxal condensation product was then crushed, for example, formed into flakes. During the reaction the aldehyde equivalents in the reaction mixture were maintained at a level of less than about 70% equivalents of aldehyde in the total amount of glyoxal to be charged to form the phenol-glyoxal condensation product. The properties of the phenol-glyoxal condensation product appear in the following tables. In the following tables, this example is also indicated as EJ1. EXAMPLE 2 (COMPARATIVE) PREPARATION OF POLYPHENOL PHENOL-GLIOXAL AT 90 ° C WITH AN ADDITION OF GLIOXAL To 576 g (6.12 moles) of phenol and 23 g of oxalic acid dihydrate at a temperature of 85 ° C were added in a period of About 1 hour 151.4 g of 40% glyoxal in water (1.04 moles) during this period the temperature was slowly raised to 90 ° C. The molar ratio between glyoxal and phenol was 0.17. Immediately after, vacuum was applied to remove 120 g of distillate at a temperature of 90-95 ° C for a period of 60 minutes. A temperature of 90-92 ° C was maintained for 2.25 hours after said time approximately 82% of the charged aldehyde equivalents had reacted. Vacuum was then applied for 15 minutes to remove 13.3 g of distillate. The heating continued at a temperature of 90 ° C to 91 ° C for 1.25 hours. After a period of 1.25 hours, approximately 88% of the charged aldehyde equivalents had reacted. It was then applied vacuum for 6 minutes to remove 6.68 g of distillate. The heating at 90 ° C continued for 5 hours and one hour at 100 ° C. After said heating for 1 hour, approximately 94% of the aldehyde equivalents charged to the reaction mixture had reacted. The reaction mixture was distilled atmospherically at a temperature of 160 ° C. The temperature of 160 ° C was maintained for one hour. The reaction mixture was then distilled in vacuo to remove most of the unreacted phenol at 155-160 ° C and the vacuum distillation proceeded at 190 ° C until the phenol in the reaction mixture was less than 1. %. During the vacuum distillation, the reaction mixture was heated to a temperature of about 175 ° C to 192 ° C for about 0.25 hours. The reaction mixture is then discharged from the reactor and crushed, for example, formed into flakes. The properties of the polyphenol product of this example are given in the following tables and this example can be known as EJ2. EXAMPLE 3 (COMPARATIVE) PREPARATION OF PHENOL-GLIOXAL POLYPHENOL AT 102 ° C AND REFLUX (103-104 ° C) WITH AN ADDITION OF GLIOXAL TO 576 g (6.12 moles) of phenol and 23 g of oxalic acid dihydrate at 90 ° C They added in a one hour period 151.4 g of glyoxal to 40% in water (1.04 moles) while the temperature was allowed to rise to reflux (103-104 ° C). The molar ratio between glyoxal and phenol was 0.17. The reaction mixture was kept at reflux for 10 hours. After said reflux approximately 89% of the aldehyde equivalents had reacted. The temperature was then raised to 110 ° C and then 55.5 g of distillate were removed over a period of about 22 minutes. The temperature was maintained at 110 ° C for one hour and then the reaction mixture was distilled atmospheric at 160 ° C. The reaction mixture was then maintained for one hour at 160 ° C. The reaction mixture was then distilled in vacuo to remove most of the unreacted phenol at 155-160 ° C and the vacuum distillation was then continued at 176 ° C until the phenol in the reaction mixture was less than 3%. During the reaction, the aldehyde equivalents in the reaction mixture were maintained at less than about 70% of the aldehyde equivalents in the total amount of glyoxal to be charged to prepare the condensation product. The reaction mixture was then discharged from the reactor and crushed, for example, formed into flakes. Properties of the polyphenol product of this example appear in the following tables and this example is known as EJ3. EXAMPLE 4 (COMPARATIVE) PREPARATION OF PHENOL-GLIOXAL POLYPHENOL AT 102 ° C AND REFLUX (103-104 ° C) WITH AN ADDITION OF GLIOXAL TO 576 g (6.12 moles) of phenol and 6.23 g of 18.5% HCl (0.2 HCl) % in phenol) at 90 ° C, 151.4 g of 40% glyoxal in water (1.04 mol) were added over a period of one hour while the temperature was allowed to rise to reflux (103-104 ° C). The molar ratio between glyoxal and phenol was 0.17. After two hours at reflux, approximately 93% of the charged aldehyde equivalents had reacted. The reaction mixture was then distilled in vacuo with the temperature rising to 110 ° C to remove the distillate of aqueous HCl from 116.4 g. Then 100 g of hot water were added to the reaction mixture and the distillation was continued at atmospheric pressure at a temperature of 150 ° C. The hydrochloric acid (HCl) catalyst is co-spelled with water from the reaction mixture. Then, by vacuum distillation to a temperature of 180 ° C, the unreacted phenol was removed to less than 4% remaining in the reaction mixture. The reaction mixture is then discharged from the reactor and crushed, for example, formed in flakes. The properties of the polyphenol product of this example appear in the tables that follow and this example is known as EJ. EXAMPLE 5 (COMPARATIVE) PREPARATION OF PHENOL-GLIOXAL POLYPHENOL AT 102 ° C AND REFLUX (103-104 ° C) WITH AN ADDITION OF GLIOXAL AND CATALYST OF PHENOLSULPHONIC ACID TO 576 g (6.12 moles) of phenol and 5.76 g (grams) (1.5 % based on phenol) of 65% phenolsulfonic acid at a temperature of 90 ° C as a catalyst is added in a period of one hour the amount of 151.4 g of 40% glyoxal in water (1.04 mol). The molar ratio between glyoxal and phenol is 0.17. The temperature of the reaction mixture is allowed to rise to reflux (103-104 ° C) where it is maintained for several hours and the conversion of aldehyde equivalents was up to about 96% of the charged. This is followed by neutralization of the catalyst, cooling to a temperature of 65 ° C and washing with distilled water to remove salt. This is followed by distillation at atmospheric pressure at a temperature of 160 ° C and then vacuum distillation at a temperature of about 176 ° C to reduce the amount of unreacted phenol in the reaction mixture to about 1%. The reaction mixture is optionally crushed, for example, formed into flakes. EXAMPLE 5A (COMPARATIVE) The procedure of the previous example 5 was followed but the phenolsulfonic acid was replaced by 1.25 g (0.22% based on the phenol) of anhydrous methanesulfonic acid. Approximately 97% of the charged aldehyde equivalents reacted before neutralization of the catalyst. Essentially, equivalent properties, equivalent molecular weights, equivalent viscosities and equivalent TPE percentage are obtained. The properties of the phenol-glyoxal condensation product appear in the following tables where this example is mentioned as EJ 5A. EXAMPLE 6 GREEN SCALE PRODUCTION OF PHENOL-GLIOXAL CONDENSATION PRODUCT IN THE MANNER INDICATED IN EXAMPLE 1 The phenol-glyoxal condensation product of Example 6 was prepared in substantially the same manner as in Example 1 except that it was prepared in a large-scale equipment that can produce hundreds of kilograms of product and was sprayed with vacuum steam at a temperature of 190 ° C to reduce the phenol level below 0.1%. The insoluble parts in percentage were 0.04% in the case of the phenol-glyoxal condensation product of this example while other properties appear in tables that follow where this example is known as EJ6. The insoluble particulate test was carried out essentially by dissolving 15 g (grams) of condensate in 285 ml (milliliters) of isopropanol, by filtering through a Whatman No. 42 filter paper, and then by drying the paper in an oven at a temperature of 75 ° C to 100 ° C for 30 minutes.

EXAMPLE 7 GREAT SCALE PRODUCTION OF PHENOL-GLIOXAL CONDENSATION IN THE MANNER INDICATED IN EXAMPLE 1 The phenol-glyoxal condensation product of Example 7 was prepared in the same manner as the condensation product of Example 6, except that It was prepared at a different time. The insoluble parts in percentage in the product were 0.01% while other properties appear in following tables where this example is indicated by EJ7. The test for insoluble parts was carried out in the same manner as in Example 6 above. EXAMPLE 8 PREPARATION OF POLYGLICIDYL ETHER RESIN (EPOXY RESIN) A one liter bottle was loaded with: 75 g (grams) of the reaction product in flakes of Example 6; 200 g of isopropyl alcohol; and 52.5 g of water to form a reaction mixture. The reaction mixture was heated to a temperature of 55 ° C. After 10 minutes 388.5 g of epichlorohydrin were added. The reaction mixture was reheated to 55 ° C and then 30 g of a 20% solution of sodium hydroxide in water was added while maintaining a temperature of 55 ° C. The temperature of 55 ° C was maintained for an additional 30 minutes. Then 90 g of a 20% solution of sodium hydroxide was added in < Water. The reaction mixture was maintained at a temperature of 55 ° C for another hour, heated to 65 ° C and maintained for 30 minutes and then transferred to a separatory funnel. The upper light brown organic layer (145.6 g) was stirred with 150 g of water and 50 g of dry ice. The aqueous layer was discarded and the organic layer was washed a second time and then distilled in vacuo to recover the excess hepichlorohydrin and 105 g dark resin from the epoxidized product of example 6. This epoxy resin had a weight per epoxy equivalent of 203.1 and 225.8. This is compared to a weight per epoxy equivalent of 210 in the case of EPON 1031. Viscosities and weights per epoxide equivalent (WPE) of the epoxy resin of this example 8 as well as comparisons with other epoxy resins prepared from polyphenols appear below in the tables where this example is indicated by EJ8. EXAMPLE 9 (COMPARATIVE) PREPARATION OF PHENOL-GLIOXAL POLYPHENOL USING ACID ION EXCHANGE RESIN (SULPHONIC ACID) To 709.3 g of phenol (7.54 moles) and 35.5 g of Amberlyst 15 which is a dried sulphonic acid ion exchange resin sold by Rohm & Haas Co. at a temperature of 90 ° C for 30 minutes, 93 g of 40% glyoxal in water (0.64 moles) were added. This resin was used since the resin used as a catalyst in the North American patents: 5,012,016; 5,146,006; and 5,191,128, all of S. Li, were not available and this resin appeared to be the closest to said resin. The temperature was maintained at 90 ° C for another period of 1.5 hours. After this period of time, 88% of the aldehyde equivalents charged to the reaction mixture had reacted. Then 42 g of the distillate was distilled in vacuo. At the end of the distillation 95% of the aldehyde equivalents charged to the reaction mixture had reacted. An additional 93 g of 40% glyoxal in water was added over a period of 31 minutes while the temperature was maintained at 90 ° C for 1.5 hours. After said 1.5 hour period, 81% of the aldehyde equivalents charged to the reaction mixture had reacted. Then 70 g of distillate at 90 ° C was subjected to vacuum distillation over a period of 30 minutes. The temperature of 90 ° C was maintained for an additional 30 minutes after which 91% of the aldehyde equivalents charged to the reaction mixture had reacted. The molar ratio between glyoxal and phenol for the total of the two glyoxal additions was 0.17. The catalyst was allowed to settle and a relatively clear liquor (687 g) was decanted and neutralized to a pH of 6 with 2.6 g of 50% sodium hydroxide. 650 g of a neutralized solution was charged to a flask for atmospheric distillation at 160 ° C. The reaction mixture was then distilled in vacuo at 175 ° C to remove the phenol. During the reaction, the aldehyde equivalents in the reaction mixture were maintained at less than about 70% of the aldehyde equivalents in the total amount of glyoxal to be charged to prepare the polyphenol. The yield of the product was 263 g. The resulting polyphenol was then ground, for example, formed into flakes. The polyphenol properties appear in the following tables where this example is mentioned as EJ9. EXAMPLE 10 PREPARATION OF PHENOL-GLIOXAL CONDENSATION PRODUCT WITH TWO ADDITIONS OF GLIOXAL, CATALYZER OF OXALIC ACID AND TOTAL GLIOXAL / PHENOL MOLAR RATIO OF 0.22 FOR THE FIRST PORTION AND ADDITION OF PHENOL TO REDUCE THE GLIOXAL / PHENOL MOLAR RELATIONSHIP TO 0.17 FOR THE SECOND PORTION At 1419 g (15 moles) of phenol and 56.5 g of oxalic acid dihydrate at 90 ° C, 240 g of 40% glyoxal in water (1655 moles) were added in 30 minutes. The temperature was maintained at 90 ° C for an additional 1.5 hours and then 148.3 g of distillate were distilled in vacuo from the reaction mixture at 90 ° C for a period of 15 minutes during which approximately 62% of the equivalents of aldehyde charged to the reaction mixture had reacted after said fifteen minute period. An additional 240 g of 40% glyoxal in water (1655 moles) was added to the reaction mixture over a period of 22 minutes while the temperature was maintained at 90 ° C for 1.5 hours. Approximately 58% of the aldehyde equivalents charged to the reaction mixture had reacted after this 1.5 hour period. 212.2 g of distillate were distilled in vacuo at a temperature of 90 ° C in a period of 45 minutes. After said 45 minute period, approximately 65% of the aldehyde equivalents charged to the reaction mixture had reacted. The molar ratio between glyoxal and phenol for the total of all glyoxal additions can be 0.22. the temperature of 90 ° C was maintained for an additional 5 hours. After said 5 hour period, approximately 87% of the aldehyde equivalents charged to the reaction mixture had reacted. Then the reaction mixture was divided in two. To one half (794 g) 214 g of phenol were added to adjust the glyoxal / phenol molar ratio to 0.17. The reaction mixture with added phenol was heated at 90 ° C for 2.5 hours and 89% of the aldehyde equivalents charged to the reaction mixture had reacted. The percentage of water in the reaction mixture was 4.9%. the reaction mixture was then heated to a temperature of 160 ° C for 25 minutes and maintained at 160 ° C for one hour, after which most of the phenol was removed by vacuum distillation at a temperature of 175 ° C. C. The product was then discharged from the bottle. The remaining half of the reaction mixture without added phenol was heated to a temperature of 160 ° C as indicated above and the phenol was removed by vacuum distillation at 175 ° C. The condensation product of phenol-glyoxal prepared with the molar ratio of 0.22 between glyoxal and phenol is indicated in the tables as EJ10.22 while the product made with the molar ratio of 0.17 between glyoxal and phenol is known in the tables as EJ10 .17. During the reaction, both leg EJ10.17 and EJ10.22, the aldehyde equivalents in the reaction mixture were maintained at less than about 70% of the aldehyde equivalents in the total amount of glyoxal to be charged to produce the product of phenol-glyoxal condensation. The properties of polyphenols appear in the following tables. The polyphenol of EJ10.17 and the polyphenol EJ10.12 were further heated at 190 ° C for one hour in total vacuum. The properties of these products appear in the following tables where the heated sample EJ10.17 is known as EJ10.17H and the heated sample of EJ10.22 is known as EJ10.22H. It can be seen from the tables that the heated samples have improved optical properties. Example 11 Preparation of phenol-glyoxal condensation products with two additions of glyoxal, glycol-phenol molar reaction of 0.17 with trichloroacetic acid catalyst and use of basic material to remove HCL. To 7.09 g (7.54 moles) of phenol and 17.7 g of trichloroacetic acid (2.5% based on the weight of the charged phenol) at 90 ° C were added in 27 minutes 92.9 g of 40% glyoxal (0.64 moles) in water. The temperature was maintained for 1.5 hours and approximately 58% of the aldehyde equivalents had reacted after said 1.5 hour period. Subsequently, 62.2 g of distillate were distilled in vacuo from the reaction mixture at a temperature of 90 ° C in 26 minutes. After distillation, the converted (converted) aldehyde equivalents accounted for 70% of the charged equivalents and the residual water content of the reaction mixture was approximately 3.5%. An additional 92.9 g of glyoxal at 40% (0.64 moles out of a total of 1.28 mmol) was added in half an hour while the temperature was maintained for 1.5 hours. The total molar ratio between glyoxal and phenol in this example was 0.17. after said heating, approximately 62% of the aldehyde equivalents charged to the reaction mixture had reacted. Subsequently, 81.6 g of distillate were distilled in vacuo at a temperature of 90 ° C in 25 minutes. After distillation the converted aldehyde equivalents represented 72% of the charged equivalents and the residual water in the reaction mixture was 3.5%. The temperature was maintained at 90 ° C for an additional 1.5 hours and approximately 88% of the charged aldehyde equivalents had reacted after said 1.5 hour period. Half an hour later 1.0 g of pyridine was added. At this time 88% of the aldehyde equivalents that had been charged to the reaction mixture had reacted. The temperature was raised to 125 ° C in a half hour and this level was maintained for 70 minutes and further raised to 160 ° C for 1.5 hours and kept at this temperature for 23 minutes to complete 1 acid decomposition. The phenol-glyoxal condensation product was further heated at 190 ° C for one hour under full vacuum to remove the unreacted phenol and prepare the phenol-glyoxal condensation product which is also known as EJ11 in the following tables. During the reaction, the aldehyde equivalents in 1 reaction mixture were maintained at less than about 60% equivalents of aldehyde in 1 total amount of glyoxal to be charged to make the phenol-glyoxal condensation product. Example 12 (comparative) Preparation of phenol-glyoxal condensation products with two additions of glyoxal, glyoxal-phenol molar ratio of 0.17 with trichloroacetic acid catalyst without use of basic material in the removal of HCL The same procedure was used as in the example 11 except that: a basic material such as, for example, pyridine was added to the reaction mixture before the temperature rise 125 ° C and catalyst removal; and the final temperature after the removal of the phenol was 175 ° C. The processing of this example was suspended upon heating to 175 ° C due to the fact that the viscosity was excessively high. This example is also known in the tables as EJ12. TABLE 1 CHARACTERIZATION OF SOME PHENOL-GLIOXAL POLYPHENOLS EJ Phenol Weight% TPE% Molecular Cps Viscosity (175 ° C) Mw / Mn 1 451/331 0.15 4.15 480 2 464/347 0.29 5.10 510 (465/362) (a) 3 468/351 2.05 8.53 300 * 4 572/387 3.46 13.21 900 * 5A 538/376 1.13 10.1 891 6 494/353 0.04 1.73 530 7 508/358 0.04 2.74 670 9 475/356 0.19 10.42 2.400 10.17 485/348 3.80 5.5 350 * 10.17H 496/357 < 0.05 5.79 1088 10.22 518/364 3.88 5.60 400 * 10.22H 528/366 < 0.05 4.83 1700 11 518/363 0.3 4.85 2040 12 552/357 0.30 1.02 > 9,000 (a) value before catalyst removal. * These examples have a high phenol content that decreases viscosity. It can be seen from Table 1 above that Examples 1, 6 and 7 provided the lowest percentage of TPE even when Examples 1-3 employed the same catalyst and the same molar ratio of reagents. Conventional catalysts such as HCl (EJ4), sulfonic acid (EK5A and 9) provide very high levels of TPE and even oxalic acid when not used with incremental additions of glyoxal and distillate removal also provided a high TPE value (EJ3) The subsequent heating to 190 ° C in Examples 10.17H and 10.22H does not show any significant effect on the molecular weight of free TPE but decreases the free phenol content and increases the viscosity TABLE 2 FLUORESCENCE DATA OBTAINED FROM A SOLUTION TO 0.05% POLYPHENOL OR POLYPHENOL EPOXIDED IN THRETHROPHURAN (THF) AT THE TIME OF ACQUISITION OF 1 SECOND AND A LENGTH OF EXCITATION OF 442 NM Example of Product Length Counts intensity maximum wave, maximum nm 1 11232 526 5A 6516 532 6 11502 538 7 10535 532 * EP0N 1031 6403 528 * EPON 1031 (VAS: 7328-97-4) is a polyphenol containing tetraklycidyl ether of tetrakis (hydroxyphenyl) ethane and is sold by She ll Oil Co. of Emeryville, CA. It can be seen from table 2 above that examples 1, 6 and 7 which are phenol-glyoxal condensation products of this invention showed a fluorescence that was about 70% higher than example 5A which was prepared with a sulfonic acid. Similar results appear in tables 3 and 4 presented below. TABLE 3 FLUORESCENCE OF A 0.05% POLYPHENOL SOLUTION OF EPOXYED IN THF AT AN EXCITATION WAVELENGTH OF 442 NM T AN ACQUISITION TIME OF 1.0 SECOND Material Maximum current intensity wavelength nm EPON 1031 9640 527 EX 8 14,600 535 It can be seen from Table 3 that the product of Example 8, that is, the epoxidized product of Example 65, shows fluorescence approximately 50% higher than the commercial product EPON 10 31. TABLE 4 FLUORESCENCE DATA OBTAINED FROM A 0.05% SOLUTION OF POLYPHENOL IN TETRAHYDROFURAN (THF) WITH A PURCHASE TIME OF A SECOND AND IN AN EXCITATION WAVE LENGTH OF 442 NM WITH THE DATA OF THIS TABLE 4 OBTAINED AT A DIFFERENT DATE OF THE DATE OF TABLES 2 AND 3. Example Percentage in counting of maximum intensity wavelength nm maximum polyphenol 1 0.0500 16640 530 1 0.0500 16300 531 2 0.0503 13550 530 2 0.0503 13510 529 3 0.0500 12860 536 3 0.0500 12640 532 4 0.0500 13960 523 4 0.0490 13850 525 5A 0.050 9920 535 5A 0.050 9620 530 2 * 0.0498 6940 540 3 * 0.0501 5130 530 3 * 0.0501 5280 527 5A * 0.0503 5010 530 * The values for these examples were the values of the reaction mixture before the catalyst is removed. It can be seen from Table 4 that Example 1 has a fluorescence that is substantially greater than the fluorescence observed in the other examples, including Examples 2 and 3 which employ the same catalyst in the same molar ratio of reagents. TABLE 5 ABSORBANCE DATA OF ULTRAVIOLET (UV) LIGHT IN DILUTED TETRAHYDROFURAN (10 MG / 100 ML) Material At 350 nm At 365 nm Example 1 0.544 0.300 Example 2 0.470 0.258 E j emplo 3 0.500 0.270 Example 5A 0.367 0.220 EP * of Example 5A 0.290 0.168 Example 6 0.515 0.288 Example 8 0.400 0.223 Example 9 0.266 0.134 EJ10.17 0.385 0.216 EJ10.17H 0.416 0.224 EJ10.22 0.418 0.239 EJ10.22H 0.470 0.258 EJ11 0.728, 0.395, 0.739 0.404 EJ12 0.465 0.317 Epon 1031 0.273 0.161 Pure TPE 0.000 0.000 * Epoxide It can be seen from Table 5 that Example 1 and Example 11 provided the highest absorbency at both 350 and 635 nm. All products catalyzed with oxalic acid gave a higher absorbency compared to the sulphonic acid catalyzed products of examples 5A and 9. All other things being equal, the higher concentrations of TPE provide lower optical properties. Likewise, it should be noted that TPE does not exhibit absorbance under test conditions. It should also be noted that the products of the phenol-glyoxal condensation of example 10 and example 11 that were heated at 190 ° C for one hour, ie EJ10.17H, EJ10.22H and EJ11 exhibited better optical properties compared to the product before said heating, that is, EJ10.17 and EJ10.22. Furthermore, it can be seen that the epoxidized product of example 6, ie example 8, provided a significantly higher absorbency than the commercial product EPON 1031. Even though the product of example 2 showed high absorbency values, its viscosity was excessively high, namely, more than 9000 cps at 175 ° C as shown in table 1 above, and therefore unacceptable. TABLE 6 VISCOSITIES AND WEIGHT BY EPOXY EQUIVALENTS (PE) Material Mw / Mn Viscosity, cps WPE Epon 1031 895/395 14880 (100 ° C) 997 216 (125 ° C) 172 (150 ° C) Epoxy 576/348 12210 (100 ° C) 214 Example 6 1580 (125 ° C) 440 (150 ° C) Epoxide 767/374 11580 (100 ° C) 821 233 from Example 5¡ (125 ° C) 142 (150 ° C) TABLE 7 FLUORESCENCE OBTAINED FROM PRODUCTS IN A 0.05% SOLUTION IN THF AT AGITATION WAVE LENGTHS OF 442 NM, BUT WITH A TIME OF ACQUISITION OF HALF OF A SECOND. Counting product in intensity Maximum maximum wavelength, nm EJ6 19,960 531 EJ11 17,390 532 EJ10.22 19,040 530 EJ10.22H 19.940 530 EJ10.17H 20,120 530 TABLE 8 SOLUBILITY OF CONDENSATION PRODUCTS Solubility to 50% acetone was attempted with several condensates of phenol-glyoxal. A large 7/8 inch ID bottle was loaded with 10 g each of acetone and solid, heated with vigorous stirring and then allowed to sit for 10 days at room temperature. The total height of the mixtures was 1.75 inches. The clear supernatant layer was measured and then reported in millimeters (mm). Lower values indicate a lower solubility. Material Light liquor, inm EJ1 32 EJ2 30EJ48 EJ5A 23 EJ10.17 23 EJ10.22 22 EJ6 41 EJ9 7 EJ11 24 Several materials were reviewed to determine solubility at 50 & in methyl ethyl ketone. The product of examples 1-3 and 11 remained totally soluble at room temperature after resting for 10 days. The product of Example 5A deposited a certain amount of product after three days of rest. TABLE 9 CONTENT OF ION METAL OF POLYPHENOLS AND EPON 1031 Ion metal EJ1 EJ6 EJ7 EJ5A EPON 1031 Na 0.003 0.001 0.002 0.017 0.028 Ca 0. 002 0.001 0.001 < 0.001 0.001 Fe < 0.001 < 0.001 0.001 < 0.001 < 0.001 K 0.008 < 0.001 < 0.001 Z0.001 0.001

Claims

CLAIMS A method for preparing a phenol-glyoxal product from a monohydric and glyoxal phenol comprising: (a) charging the phenol to a reaction vessel and incrementally charging a total of about 0. 15 to 0.22 mol of glyoxal for each mole of the phenol charged to the reaction vessel to form a reaction mixture at a temperature of about 80 ° C 100 ° C in the presence of about 1% to 6%, based on the weight of the charged phenol, of an acid catalyst that can be removed from the reaction mixture by heating and distilling the reaction mixture at a temperature below about 170 ° C, said catalyst being selected from the group consisting of acid oxalic acid, trichloroacetic acid and trifluoroacetic acid; (b) incrementally removing the water from the reaction mixture; (c) maintaining the aldehyde units in the reaction mixture at a level of less than about 70% of the aldehyde units in the total amount of glyoxal to be charged to form the condensation product; (d) distilling the reaction mixture at a temperature of less than about 170 ° C to remove the acid catalyst when at least 85% of the aldehyde units in the total amount of glyoxal to be charged to produce the condensation product has reacted, provided that before said distillation a basic material is added to the reaction mixture in an amount sufficient to neutralize the hydrochloric acid when the catalyst is trichloroacetic acid; (e) heating the reaction mixture to a temperature of about 175 ° C to 200 ° C for about 0.25 hour to 3 hours after step (d) above; (f) removing the unreacted phenol from the reaction mixture to obtain a phenol-glyoxal condensation product containing less than about 5% by weight of phenol.
The method according to claim 1, wherein the aldehyde units are measured as aldehyde equivalents.
The method according to claim 2, wherein the incremental additions of the glyoxal are continuous additions.
The method according to claim 2, wherein the acid catalyst is selected from the group consisting of trifluoroacetic acid and oxalic acid and the reaction mixture is heated to a temperature of about 180 ° C to 195 ° C for about 0.5 2 hours after the removal of the catalyst.
The method according to claim 2, wherein: (a) of the phenol is a mononuclear monohydroxyphenol having from 6 to 12 carbon atoms; (b) the catalyst is oxalic acid in an amount of about 3% to 5%; (c) the total number of incremental glyoxal additions is from about 2 to 4; (d) the water is distilled from the reaction mixture following each reaction after each addition of glyoxal; and (e) the aldehyde equivalents are maintained at a level of less than about 60% of the aldehyde equivalents in the total amount of glyoxal to be charged to prepare the condensation product.
The method according to claim 2, wherein the reaction mixture is distilled to move the acid catalyst when at least about 90% of the aldehyde equivalents of the total amount of glyoxal to be charged to the reaction mixture for elaborate the product of the reaction has reacted.
The method according to claim 2, wherein the phenol is phenol itself and the condensation product of phenol-glyoxal contains from about 1% to about 6% tetrakis (4-hydroxyphenyl) ethane.
The method according to claim 2, wherein the phenol-glyoxal condensation product contains less than about 1.5% unreacted phenol.
The method according to claim 2, wherein the phenol-glyoxal condensation product has an ultra violet light absorbance of at least 0.260 at 365 nm and / or 0.44 at 350 nm.
The method according to claim 2, wherein the catalyst is oxalic acid in an amount of about 3% to 5%; phenol is phenol itself; the aldehyde equivalents in the reaction mixture are maintained at less than about 60% of the aldehyde equivalents in the total amount of glyoxal to be charged to the reaction mixture to prepare the condensation product; two to four additions of glyoxal are made to the reaction mixture; water distillation is carried out after each addition of glyoxal and glyoxal reaction with phenol before implementing the temperature above about 130 ° C to remove the catalyst; the amount of unreacted phenol is from the condensation product of phenol-glyoxal is less than about 4%; and the ultraviolet absorbance of the product is at the lower 0.275 at 365 nm and / or 0.450 at 350 nm.
11. The phenol-glyoxal condensation product produced by the method of claim 2.
12. The phenol-glyoxal condensation product produced by the method of claim 10.
13. A method for preparing a phenol condensation product. glycol from a monohydric and glyoxal phenol comprising: (a) charging phenol to a reaction vessel and incrementally charging a total of about 0.15 to 0.22 mol of glyoxal for each mole of the phenol charged to the reaction vessel to form a reaction mixture at a temperature of about 80 ° C to 100 ° C in the presence of about 1% to 4%, based on the weight of the charged phenol, of trichloroacetic acid as the catalyst; (b) incrementally removing the water from the reaction mixture; (c) maintaining the aldehyde equivalents in the reaction mixture less than about 70% of the aldehyde equivalents in the total amount of glyoxal to be charged to make the condensation product; (d) adding a basic material to the reaction mixture in an amount sufficient to neutralize the eventual hydrochloric acid formed when at least 85% of the aldehyde equivalents in the total amount of glyoxal to be charged to produce the condensation product has reacted; (e) distilling the reaction mixture at a temperature less than about 170 ° C to remove the acid catalyst; (f) heating the reaction mixture to a temperature of about 175 ° C to 200 ° C for about 0.25 hours to 3 hours after the removal of the catalyst; and (g) removing the unreacted phenol from the reaction mixture to obtain a phenol-glyoxal condensation product containing less than about 5% by weight of phenol.
A method for preparing a phenol-glyoxal condensation product comprising: (a) charging, to a reaction vessel, a mononuclear monohydric phenol having up to 12 carbon atoms and from about 0.06 to 0.11 mol of a 40% solution of glyoxal in water, the amount of glyoxal based on the moles of phenol charged, to form a reaction mixture and wherein the reaction mixture is at a temperature comprised within a range of about 80 ° C to 100 ° C in presence of approximately 3 to 5% oxalic acid; (b) performing a first distillation of the reaction mixture at said reaction temperature after about 1 to 5 hours of the initial reaction of the phenol with the glyoxal in the reaction mixture and stirring from about 8% to 12% by weight of distillate, based on the amount of phenol charged, from the reaction mixture; (c) loading to the reaction mixture an additional 0.06 to 0.11 mole of the glyoxal based on the charged phenol moles where the total amount of glyoxal charged to the reaction mixture is from about 0.
15 to 0.22 mole of glyoxal for each mole of charged phenol and continue the reaction at said reaction temperature for approximately 1.5 to 6 additional hours after the start of the first distillation and then carry out a second distillation of the reaction mixture at said reaction temperature to remove from approximately 4% to 12% additional by weight of distillate based on the amount of phenol charged; (d) proceeding with the reaction after the second distillation at the reaction temperature until at least 85% of the aldehyde equivalents of the total amount of glyoxal to be charged to produce the condensation product have reacted; (e) raising the temperature above about 130 ° C to about 170 ° C and distilling the reaction mixture to remove the catalyst. (f) heating the reaction mixture to a temperature of about 175 ° C to 200 ° C for about 0.25 hours to 3 hours after the removal of the catalyst; and (g) removing the unreacted phenol to recover a phenol-glyoxal condensation product containing not less than about 5% unreacted phenol. The method according to claim 14, wherein the reaction mixture is heated to a temperature of about 190 ° C to 200 ° C for about 0.5 to about 3 hours after the removal of the catalyst.
16. The method according to claim 14, wherein the phenol-glyoxal condensation product has an ultraviolet light absorbance of at least 0.260 at 365 nm and / or 0.400 at 350 nm.
17. The method according to claim 14, wherein the catalyst is oxalic acid dihydrate; the first distillation of the reaction mixture is after about 1.5 to 3 hours from the initial reaction of the phenol with the glyoxal; the second distillation is approximately 1.5 to 5 hours from the moment of the start of the first distillation; and the reaction proceeds for an additional 0.5 to 6 hours after the start of the second distillation until at least 85% of the aldehyde equivalents of the total amount of glyoxal to be charged to make the condensation product have reacted.
18. The method according to claim 14, wherein the temperature of the reaction is from about 85 ° C to about 95 ° C.
19. The method according to claim 14, wherein the phenol is phenol itself and the phenol-glyoxal condensation product contains from about 1% to about 6% tetrakis (4-hydroxyphenyl) ethane.
20. The phenol-glyoxal condensation product produced by the method of claim 14.
21. A phenol-glyoxal condensation product having an ultraviolet light absorbance of at least 0.260 at 365 nm and / or 0.44 at 350 nm.
22. The phenol-glyoxal condensation product according to claim 21, which contains about 0% to about 6% of TPE.
23. The phenol-glyoxal condensation product according to claim 21, wherein the phenol is phenol itself.
24. The product according to claim 21, which contains a concentration less than: about 0.005% sodium; approximately 0.003% calcium; approximately 0.003% iron, and approximately 0.002% potassium.
25. An epoxy resin selected from the group consisting of a glycidylated phenol-glyoxal condensation product of claim 21, a reaction product of about 4 to 8 parts glycidyl epoxy resin to each part of a diglycidylated epoxy resin of the Claim 21, and mixtures thereof.
26. The epoxy resin according to claim 25 having a weight in epoxy equivalent of at least 140.
27. A composition comprising a flame-retardant epoxy resin and based on each 100 parts of said flame-retardant epoxy resin: (a) about 18 to 25 parts of a phenol-formaldehyde novolac resin; and (b) from about 3 to 10 parts of a member selected from the group consisting of an epoxy resin of claim 25, a phenol-glyoxal condensation product of claim 21, and mixtures thereof.
28. The composition according to claim 25, wherein the flame retardant epoxy resin is a halogenated epoxy resin.
29. A composition comprising approximately 50 to 90 parts by weight of a phenolic novolac having an ultraviolet light absorbance of less than about 0.260 at 365 nm and / or 0.44 at 350 nm and from 10 to 50 parts of phenol condensation product -glioxal having an ultraviolet light absorbance of at least 0.260 at 365 nm and / or 0.400 at 350 nm.
30. The glycidyl phenol-glyoxal condensation product of claim 21.
31. The glycidylated product of claim 30 having an ultraviolet light absorbance of at least about 0.200 to 365 nm and / or 0.300 to 35 nm.
32. A laminate having improved fluorescence, said laminate is prepared from a composition comprising an epoxy resin and for every 100 parts of said epoxy resin: (a) from about 18 to 25 parts of a phenol novolac resin formaldehyde; and (b) from about 3 to 10 parts of a selected member within the group consisting of, (i) a phenol-glyoxal condensation product of claim 21, (ii) a glycidylated phenol-glyoxal condensation product of claim 21, (iii) a reaction product of the epoxy resin and the phenol-glyoxal condensation product of claim 21, and (iv) mixtures thereof. . A laminate according to claim 32, wherein the epoxy resin is a flame-retardant epoxy resin. A laminate according to claim 33 wherein the flame retardant resin is a halogenated epoxy resin.