High nitrogen containing triazine-phenol-aldehyde condensate

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.;
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• (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.

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;
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• (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.

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;
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• (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.

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.