about 6 moles, such as from about 2 to about 3 .5 moles, of an aldehyde monomer for each mole of triazine charged to a vessel. 

[0082] The various reaction steps for preparation of the condensates by the processes as described herein may be conducted in the same reaction vessel. A non-reactive atmo› sphere, such as nitrogen gas or a noble gas, is optionally employed to minimize oxidation of aldehyde and discolora› tion of product. In the order of charging ingredients to the reaction vessel, the aldehyde is typically added after the tri› azine, phenol and catalyst except in the high pKa acid catalyst method when the high pKa catalyst may be added with or after the other components. In each of the methods for the manufacture of the condensates, when aldehydes other than formaldehyde are used, such other aldehydes are typically reacted at a temperature of about 100° C. or less prior to the addition of formaldehyde. 

## The Low pKa Value Acid Catalyst Method 

[0083] In the processes described herein for making the condensate for the low pKa value acid catalyst method, the pH of the mixture of arylhydroxy monomer and acid catalyst may be from about 2 to about 4. 

[0084] In one embodiment of the low pKa acid catalyst method, the initial reaction mixture includes an acid catalyst having a pKa acidity of from greater than about 3.8 to 6, such as a pKa acidity from about 4.1 to about 4.8. The quantity of acid varies and is generally from about 0.1 % to 1 % by weight (wt. %), such as from about 0.1 wt. % to 0.5 wt. %, for example, from about 0.2 wt. % to 0.4 wt. %, based on the quantity of arylhydroxy monomer charged. Suitable acid catalysts that may be used in the low pKa acid catalyst method include the acid mentioned herein, and preferably include an acid selected from the group of acetic acid, adipic acid, ascor› bic acid, benzoic acid, cinnamic acid, succinic acid, and com› binations thereof, among others. 

[0085] One embodiment of the process to form a conden› sate from triazine monomers, arylhydroxy monomers, and aldehyde monomers includes charging the triazine monomer to a reaction vessel, charging from about 3 to about 30 moles, such as about 9 to about 14 moles ofan arylhydroxy monomer for each mole of triazine monomer with about O .1 wt. % to 0. 5 wt. % of the acid catalyst described herein relative to the weight of the arylhydroxy monomer. The acid catalyst may have a pKa of about 3.8 to 6, such as a pKa acidity from about 4.1 to about 4.8. In one example, the triazine monomer is triazine, the arylhydroxy monomer is phenol, the aldehyde monomer is formaldehyde, and benzoic acid is the acid cata› lyst. 

[0086] The reaction mixture is then heated at a temperature of about 70° C. to 110° C. and then about 50% to 63% of the total from about 1 mole to 6 moles, such as from about moles 2.2 to 3.2 moles (i.e., from about 1.1 to about 2.0moles for the from about moles 2.2 to 3 .2 moles), ofaldehyde monomer for each mole of triazine monomer may be then charged to the reaction vessel in one or more additions at this temperature. Alternatively, the entire aldehyde monomer or the aldehyde modified triazine compound, such as in HMMM described above, may be charged to the reaction vessel on one addition process. The reaction mixture is then heated to a temperature of about 120° C. to about 140° C. to effect copolymerization of the three monomers and to remove water and the tempera› ture is maintained for about 1 to about 2 hours. 

[0087] The reaction mixture is then cooled to a temperature which does not exceed about 110° C., such as that of about 70° C. to about 110° C., and the remainder of the aldehyde monomer is added. The reaction mixture is then heated to a temperature above 120° C. to continue copolymerization and remove water and the temperature is maintained for about 1 to about 2 hours until the reaction of the arylhydroxy monomer is substantially complete. 

[0088] The reaction mixture may then be heated to a tem› perature of about 145° C. to about 165° C. to continue remov› ing water from the reaction mixture. The reaction mixture is then distilled under full vacuum to remove most of the non› reacted arylhydroxy monomer. Optionally, the reaction mix› ture may then be further heated to further remove additional amounts of the arylhydroxy monomer from the condensate, for example, to a temperature not exceeding 180° C. for phenol removal, when steam sparging is adopted to remove trace amounts of the arylhydroxy monomer from the conden› sate. 

[0089] The recovered condensates were observed to have a range of viscosity from about 200 cps to about less than 3000 cps, for example as from about 1100 cps to about 1700 cps, and contain from about 8 wt. % to about 28 wt. % nitrogen content, for example, from greater than 10 wt. % to about 23 wt. % nitrogen content. The recovered condensates exhibited a solubility in one or more organic solvents having one or more functionalities selected from the group of an ether func› tionality, a ketone functionality, an alcohol functionality, an ester functionality, and combinations thereof, of which methyl ethyl ketone (MEK) is preferably used, up to 80 wt.% solids ( or higher), such as from about 33 wt. % solids to about 75 wt. % solids to give a transparent solution (no turbidity) that stayed dissolved for an indefinite period of time, such as greater than or equal to 120hours. For example, the recovered condensates in the MEK solutions from about 33 wt. % solids to 80 wt. % and higher stayed dissolved for an indefinite period of time, such as greater than 500 hours. 

[0090] Alternatively, subsequent to arylhydroxy monomer removal by vacuum distillation and/or steam sparging, the condensate is cooled to temperatures less than 165° C. and tested for melt viscosity. If the viscosity is higher than the desired value, such as about 1400 cps, a small amount of an additive also referred to as a stabilizer ( or diluent), of about 0.1 to about 2% relative to the weight of the condensate may be added. The addition of stabilizer helps control the viscosity of the resin from increasing significantly when held at elevated temperatures for longer duration during the solidifi› cation (flaking) process depending on the size of the batch. 

[0091] A further aspect for the low pKa acid method is to produce the solid product described by any of the low pKa processes described herein, and add a stabilizer or alterna› tively, to further dissolve the product in one or more organic solvents having one or more functionalities selected from the group of an ether functionality, a ketone functionality, an alcohol functionality, an ester functionality, and combina› tions thereof, of which methyl ethyl ketone (MEK) is prefer› ably used, and finish as a composition preferably of from about 30 wt. % to about 60 wt. % solids. 

## The High pKa Acid Catalyst Method 

[0092] In the processes described herein for making the condensate for the high pKa value acid catalyst method, the pH of the mixture of arylhydroxy monomer and acid catalyst may be from about 4 to about 6. 

