Jun.  16,2016  8  US 2016/0168306 Al  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.  [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.  [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.  The High pKa Acid Catalyst Method  The Low pKa Value Acid Catalyst Method 