High nitrogen containing triazine-phenol-aldehyde condensate

Abstract

There is disclosed a triazine-phenol-aldehyde condensate which contains at least 15% of nitrogen, has a melt viscosity of not greater than 2,000 cps at 175° C. and a solubility of at least 80% by weight at 25° C. by the 90:10 methanol: water method. Also disclosed are methods for the manufacture of the condensate as well as its use in fire-retardant epoxy resin compositions suitable for the manufacture of laminates for electronic applications. Additionally, disclosed is a composition comprising a physical mixture of a triazine-phenol-aldehyde condensate with benzoguanamine and/or acetoguanamine wherein the mixture contains from about 0.5% to 20% of benzoguanamine, acetoguanamine and mixtures thereof based on the weight of the condensate. There is also disclosed a glycidylated triazine-phenol-aldehyde condensate of this invention.

What is claimed is:  
     
         1 . A method for the preparation of a triazine-phenol-aldehyde condensate which comprises: 
 (A) charging to a reaction vessel, a triazine, about 6 to 12 moles of a phenol for each mole of triazine, about 0.1% to 2% by weight based on the phenol, of a secondary or tertiary amine having a pK basicity of at least 10 and about 2.2 to 3.5 moles of formaldehyde for each mole of triazine to form a reaction mixture;    (B) heating the reaction mixture at a temperature of about 40° C. to about 120° C. until the reaction mixture is substantially free of formaldehyde wherein the triazine is a member selected from the group consisting of melamine, a mixture of melamine with benzoguanamine wherein the quantity of benzoguanamine is not more than about 50% by weight of the mixture, a mixture of melamine and acetoguanamine wherein the quantity of acetoguanamine is not more than about 50% by weight of the mixture, and a mixture of melamine, benzoguanamine, and acetoguanamine wherein the quantity of melamine is at least 50% by weight of the mixture, the benzoguanamine is not more than 35% by weight of the mixture and the acetoguanamine is not more than 35% by weight of the mixture, wherein said phenol is a member selected from the group consisting of phenol itself, a meta-substituted alkyl phenol wherein the alkyl group has from 1 to 4 carbon atoms, a meta-substituted alkoxy phenol having from 1 to 4 carbon atoms in the alkoxy group and a mixture of phenol, the meta-substituted alkyl phenol and the meta-substituted alkoxy phenol; and    (C) after the reaction mixture is substantially free of formaldehyde, heating the reaction mixture at a temperature of at least 100° C. and substantially completing reaction of phenol in the reaction mixture.    
     
     
         2 . The method of  claim 1  wherein up to 20 mole percent of the formaldehyde is substituted with an equal molar quantity of an aldehyde which is a member selected from the group consisting of acetaldehyde, benzaldehyde, isobutyraldehyde, crotonaldehyde, acrolein, and mixtures thereof.  
     
     
         3 . The method of  claim 1  wherein the triazine is a mixture of melamine and about 0.5% to about 50% of benzoguanamine based on the weight of the mixture.  
     
     
         4 . The method of  claim 1  wherein the triazine is melamine, the phenol is phenol itself, about 7 to 11 moles of the phenol are charged for each mole of melamine, about 2.5 to 3.0 moles of formaldehyde are charged for each mole of the triazine, and the amount of phenolic residue incorporated in the condensate varies from about 55% to 65% based on the weight of the condensate.  
     
     
         5 . The triazine-phenol-aldehyde condensate prepared by the method of  claim 1 .  
     
     
         6 . A method for the preparation of a triazine-phenol-aldehyde condensate which comprises: 
 (A) charging to a reaction vessel, a triazine, about 6 to 12 moles of a phenol for each mole of triazine, about 0.1% to about 2% of a secondary or tertiary amine having a pK basicity of less than 10, wherein the quantity of amine is based on the weight of phenol, and about 2.2 to 3.5 moles of formaldehyde for each mole of triazine to form a reaction mixture;    (B) heating the reaction mixture at a temperature of about 40° C. to about 80° C. until the reaction mixture is substantially free of formaldehyde wherein the triazine is a member selected from the group consisting of melamine, a mixture of melamine with benzoguanamine wherein the quantity of benzoguanamine is not more than about 50% by weight of the mixture, a mixture of melamine and acetoguanamine wherein the quantity of acetoguanamine is not more than about 50% by weight of the mixture, and a mixture of melamine, benzoguanamine, and acetoguanamine wherein the quantity of melamine is at least 50% by weight of the mixture, the quantity of benzoguanamine is not more than 35% by weight of the mixture and the quantity of acetoguanamine is not more than 35% by weight of the mixture and wherein the phenol is selected from the group consisting of phenol itself, a meta-alkyl phenol wherein the alkyl group has from 1 to 4 carbon atoms, a meta-alkoxy phenol having from 1 to 4 carbon atoms in the alkoxy group and a mixture of phenol, the meta-substituted alkyl phenol and the meta-substituted alkoxy phenol;    (C) adding to the reaction mixture from about 2% to 4% of an acid having a pK acidity of about 0.5 to 3.8, the quantity of said acid based on the weight of the reaction mixture, while said mixture is at a temperature of not greater than about 80° C.; and    (D) heating the reaction mixture to a temperature of at least about 100° C. to substantially complete reaction of the phenol in the reaction mixture.    
     
     
         7 . The method of  claim 6  wherein up to 20 mole percent of the formaldehyde is substituted with an equal molar quantity of an aldehyde which is a member selected from the group consisting of acetaldehyde, isobutyraldehyde, crotonaldehyde, acrolein, and mixtures thereof.  
     
     
         8 . The method of  claim 6  wherein the triazine is a mixture of at least about 50% melamine and up to about 50% by weight of benzoguanamine.  
     
     
         9 . The method of  claim 6  wherein the triazine is melamine, the phenol is phenol itself, about 2.5 to 3.0 moles of formaldehyde are charged for each mole of the melamine, about 7 to 11 moles of the phenol are charged for each mole of melamine, and the amount of phenolic residue incorporated in the condensate varies from about 55% to 65% based on the weight of the condensate.  
     
     
         10 . The method of  claim 9  wherein the acid is formic acid.  
     
     
         11 . The triazine-phenol-aldehyde condensate prepared by the method of  claim 6 .  
     
     
         12 . A method for the preparation of a triazine.-phenol-aldehyde condensate which comprises: 
 (A) charging to a reaction vessel, a triazinel 6 to 12 moles of a phenol for each mole of the triazine, about 0.05% to 0.3% of an acid based on the weight of phenol charged, said acid having a pK acidity of about 0.5 to 3.8 and about 2.2 to 3.5 moles of formaldehyde for each mole of triazine to form a reaction mixture;    (B) reacting the formaldehyde in the reaction mixture at a temperature of not greater than about 80° C. until the reaction mixture is substantially free of formaldehyde, wherein the triazine is a member selected from the group consisting of melamine, a mixture of melamine with benzoguanamine wherein the quantity of benzoguanamine is not more than about 50% by weight of the mixture, a mixture of melamine and acetoguanamine wherein the quantity of acetoguanamine is not more than about 50% by weight of the mixture, and a mixture of melamine, benzoguanamine, and acetoguanamine wherein the quantity of melamine is at least 50% by weight of the mixture, the benzoguanamine is not more than 35% by weight of the mixture, and the acetoguanamine is not more than about 35% by weight of the mixture, wherein said phenol is a member selected from the group consisting of phenol itself, a meta-substituted alkyl phenol having from 1 to 4 carbon atoms in the alkyl group, a meta-substituted alkoxy phenol having from 1 to 4 carbon atoms in the alkoxy group and a mixture of phenol, the meta-substituted alkyl phenol and the meta-substituted alkoxy phenol;    (C) charging from about 2% to about 4%, by weight of the reaction mixture of an acid based on the weight of the reaction mixture at a reaction mixture temperature of not greater than about 80° C. wherein the acid has a pK acidity in the range of about 0.5 to 3.8; and    (D) heating the reaction mixture at a temperature of at least 100° C. so as to substantially complete reaction of phenol in the reaction mixture.    
     
     
         13 . The method of  claim 12  wherein up to 20 mole percent of the formaldehyde is substituted with an equal molar quantity of an aldehyde which is a member selected from the group consisting of acetaldehyde, isobutyraldehyde, crotonaldehyde, acrolein, and mixtures thereof.  
     
     
         14 . The method of  claim 12  wherein the triazine is a mixture of melamine and about 0.5% to about 25% of benzoguanamine based on the weight of the mixture.  
     
     
         15 . The method of  claim 12  wherein the triazine is melamine, the phenol is phenol itself, about 7 to 11 moles of the phenol are charged for each mole of melamine, about 2.5 to 3.0 moles of formaldehyde are charged for each mole of the melamine, and the amount of phenolic residue incorporated in the condensate varies from about 55% to 65% by weight of the condensate.  
     
     
         16 . The method of  claim 12  wherein after addition of the formaldehyde, the reaction mixture is heated at a temperature of about 40° C. to 70° C.  
     
     
         17 . The method of  claim 14  wherein the acid is formic acid.  
     
     
         18 . The triazine-phenol-aldehyde condensate prepared by the method of  claim 12 .  
     
     
         19 . A method for the preparation of a triazine-phenol-aldehyde condensate which comprises: 
 (A) charging to a reactor, a triazine, about 6 to 12 moles of a phenol for each mole of triazine, about 0.2% to 2% of an acid based on the weight of phenol, said acid having a pK acidity in the range of about 0.5 to 3.8 and about the first half of a total of about 2.2 to 3.5 moles of formaldehyde for each mole of triazine to form a reaction mixture;    (B) heating the reaction mixture at a temperature of about 70° C. to 110° C. until the reaction mixture is substantially free of formaldehyde wherein the triazine is a member selected from the group consisting of melamine, a mixture of melamine with benzoguanamine wherein the quantity of benzoguanamine is not more than about 50% by weight of the mixture, a mixture of melamine and acetoguanamine wherein the quantity of acetoguanamine is not more than about 50% by weight of the mixture, and a mixture of melamine, benzoguanamine, and acetoguanamine wherein the quantity of melamine is at least 50% by weight of the mixture, and each of benzoguanamine and acetoguanamine is not more than 35% by weight of the mixture, wherein said phenol is a member selected from the group consisting of phenol itself, a meta-substituted alkyl phenol having from 1 to 4 carbon atoms in the alkyl group, a meta-substituted alkoxy phenol having from 1 to 4 carbon atoms in the alkoxy group and a mixture of phenol, the meta-substituted alkyl phenol and the meta-substituted alkoxy phenol;    (C) after the reaction mixture is substantially free of formaldehyde, heating the reaction mixture at a temperature and time sufficient to prevent gelation of the subsequent charge of formaldehyde;    (D) cooling the reaction mixture to about 80° C. to 110° C. and adding the remaining quantity of formaldehyde to the reaction mixture; and    (E) heating the reaction mixture at a temperature of at least about 120° C. to substantially complete reaction of the phenol in the reaction mixture.    
     
     
         20 . The method of  claim 19  wherein up to 20 mole percent of the formaldehyde is substituted with an equal molar quantity of another aldehyde wherein said other aldehyde is a member selected from the group consisting of acetaldehyde, isobutyraldehyde, benzaldehyde, crotonaldehyde, acrolein, and mixtures thereof.  
     
     
         21 . The method of  claim 19  wherein the triazine is a mixture of melamine and about 0.5% to about 25% of benzoguanamine based on the weight of the mixture.  
     
     
         22 . The method of  claim 19  wherein the triazine is melamine, the phenol is phenol itself, about 7 to 11 moles of the phenol are charged for each mole of melamine, about 2.5 to 3.0 moles of formaldehyde are charged for each mole of the triazine and the amount of phenolic residue incorporated in the condensate varies from about 55% to 65% by weight of the condensate.  
     
     
         23 . The method of  claim 19  wherein the acid is a member selected from oxalic acid, formic acid and trifluoroacetic acid.  
     
     
         24 . The method of  claim 19  wherein water and free phenol are distilled out of the reaction mixture and the condensate contains not more than 2% of free phenol.  
     
     
         25 . The method of  claim 23  wherein the acid is formic acid.  
     
     
         26 . The method of  claim 23  wherein the quantity of oxalic acid is from about 0.4 to 1.5% based on the quantity of phenol, the phenol is phenol itself, and the triazine is melamine.  
     
     
         27 . The triazine-phenol-aldehyde condensate prepared by the method of  claim 19 .  
     
     
         28 . A composition comprising a mixture of a triazine-phenol-aldehyde condensate and a member selected from the group consisting of: benzoguanamine; acetoguanamine; and a mixture of benzoguanamine and acetoguanamine wherein the quantity of said member is from about 0.5% to 20% by weight of the condensate.  
     
     
         29 . The composition of  claim 28  wherein the triazine is a member selected from the group consisting of melamine, a mixture of melamine with benzoguanamine wherein the quantity of benzoguanamine is not more than about 50% by weight of the mixture, a mixture of melamine and acetoguanamine wherein the quantity of acetoguanamine is not more than about 50% by weight of the mixture, and a mixture of melamine, benzoguanamine, and acetoguanamine wherein the quantity of melamine is at least 50% by weight of the mixture and each of the benzoguanamine and acetoguanamine is not greater than 35% by weight of the mixture, the phenol is a member selected from the group consisting of phenol itself, a meta-substituted alkyl phenol wherein the alkyl has from 1 to 4 carbon atoms in the alkyl group, a meta-substituted alkoxy phenol wherein the alkoxy group has from 1 to 4 carbon atoms in the alkoxy group, and a mixture of phenol, the meta-substituted alkyl phenol, and the meta-substituted alkoxy phenol and the aldehyde is a member selected from the group consisting of: formaldehyde; a mixture of formaldehyde and acetaldehyde; a mixture of formaldehyde and isobutyraldehyde; a mixture of formaldehyde and benzaldehyde; a mixture of formaldehyde and crotonaldehyde; a mixture of formaldehyde and acrolein; and mixtures thereof wherein the said mixtures contain formaldehyde in a quantity of at least 80 mole percent of the mixture.  
     
     
         30 . The composition of  claim 28  wherein the triazine is melamine, the phenol is phenol itself and the aldehyde is formaldehyde.  
     
     
         31 . A condensation product of a triazine, a phenol, and an aldehyde said condensation product being substantially free of water and having from about 15% to 24% nitrogen by weight, a melt viscosity of not more than about 2,000 cps at 175° C., not more than 2% by weight of free phenol and a solubility of at least 80% by weight by the 90:10 methanol:water solvent method at 25° C.  
     
     
         32 . The product of  claim 31  which contains from about 17% to 22% of nitrogen and has a melt viscosity of not more than about 1,000 cps at 175° C.  
     
     
         33 . The product of  claim 31  wherein: 
 (A) the triazine is the residue of a member selected from the group consisting of melamine, a mixture of at least 75% by weight of melamine and not more than 25% by weight of benzoguanamine, a mixture of at least 75% by weight of melamine and not more than 25% by weight of acetoguanamine, and a mixture of at least 75% by weight of melamine with the remainder being a mixture of benzoguanamine and acetoguanamine;  
 (B) the phenol is a member selected from the group consisting of the residue of phenol itself, a meta-substituted alkyl phenol having from 1 to 4 carbon atoms in the alkyl group, a meta-substituted alkoxy phenol having from 1 to 4 carbon atoms in the alkoxy group and a mixture of phenol itself and said meta-substituted alkyl phenol and meta-substituted alkoxy phenol wherein the phenol itself is at least 90% by weight of the mixture; and  
 (C) the aldehyde is the residue of formaldehyde, the residue of a mixture of formaldehyde and acetaldehyde wherein the formaldehyde is at least 80 molar percent of the mixture; the residue of a mixture of formaldehyde and benzaldehyde wherein the formaldehyde is at least 80 molar percent of the mixture; the residue of a mixture of formaldehyde and isobutyraldehyde wherein the formaldehyde is at least 80 molar percent of the mixture; the residue of a mixture of formaldehyde and crotonaldehyde wherein the formaldehyde is at least 80 molar percent of the mixture; the residue of a mixture of formaldehyde and acrolein wherein the formaldehyde is at least 80 molar percent of the mixture; and the residue of a mixture of formaldehyde, acetaldehyde, isobutyraldehyde, benzaldehyde, crotonaldehyde, and acrolein wherein the formaldehyde is at least 80 molar percent of the mixture.  
 
     
     
         34 . The product of  claim 31  wherein the condensate has incorporated therein from about 52% to 67%, by weight, of phenolic residue.  
     
     
         35 . The product of  claim 31  wherein the triazine is melamine, the phenol is phenol itself, and the aldehyde is formaldehyde.  
     
     
         36 . A halogen-free flame-retardant epoxy resin composition comprising: 
 (A) an epoxy resin;    (B) a triazine-phenol-aldehyde condensate, said condensate being substantially free of water and having from about 15% to 24% nitrogen by weight, not more than 2% by weight of free phenol, a melt viscosity of not more than 2,000 cps at 175° C. and a solubility of at least 80% by weight by the 90:10 methanol:water method at 25° C.; and    (C) a curing accelerator.    
     
     
         37 . The composition of  claim 36  which includes a phenolic-formaldehyde novolac curing agent.  
     
     
         38 . The composition of  claim 36  which includes a member selected from the group consisting of benzoguanamine, acetoguanamine and mixtures thereof in a quantity of about 0.5% to 20% by weight of the condensate.  
     
     
         39 . The composition of  claim 36  wherein the triazine is melamine, the phenol is phenol itself, the aldehyde is formaldehyde and the viscosity is not more than 1,000 cps at 175° C.  
     
     
         40 . A prepreg comprising a porous substrate impregnated with the epoxy resin composition of  claim 36 .  
     
     
         41 . A laminate comprising a plurality of prepregs according to  claim 40  laminated together wherein said epoxy resin composition is cured.  
     
     
         42 . A glycidylated triazine-phenol-aldehyde condensate, said condensate prior to glycidylation, being substantially free of water and having, by weight, from about 15% to 24% of nitrogen, not more than about 2% of free phenol, a melt viscosity of not more than 2,000 cps at 25° C. and a solubility of at least 80% by the 90:10 methanol:water solvent method at 25° C.