Abstract: Aminoplast resins are cured using inorganic particles as curing agents. The inorganic particles have a laminated structure and include interlamellarly exchangeable cations such as alkali cations, alkaline-earth cations, aluminum cations, iron cations and/or manganese cations. The aminoplast resins may be cured to produce semi-finished products and molding materials.

Abstract: The invention relates to polymer modified inorganic particles with a layer structure with an average particle diameter of 5 nm to 20,000 nm, containing 20 to 5000 mass % interlamellarly, in relation to the anhydrous inorganic particle, of a mixture of aminoplasts and water. These polymer modified inorganic particles are produced by swelling the inorganic particles with aldehydes and then reacting the inorganic particles with multifunctional C1–C30 amino compounds. The invention also relates to plastic containing polymer modified particles with a layer structure and to semi-finished products and moulded material produced from the same.

Abstract: A process for the production of melamine by pyrolysis of urea in a high-pressure reactor having a vertical central pipe is provided. The melamine flows upwards into the reactor from below, mixes in the lower part of the reactor with a urea melt, and optionally NH3, introduced into the reactor from below, and emerges from the central pipe in the upper part of the central pipe. Part of the melamine formed flows downward in the annular space between the central pipe and reactor wall, and the remainder is expelled for further work-up. The off-gases are removed at the top of the reactor. A reactor for carrying out the process is also provided.

Abstract: The invention relates to modified inorganic particles with a layer structure with an average particle diameter of 5 nm to 20000 nm, comprising an outer shell consisting of aminoplasts which contain, interlamellarly, multifunctional C1–C30 amino compounds of the melamine, melamine derivative, urea, urea derivative, guanidine, guanidine derivative, cyanamide, dicyandiamide, sulphonamide and/or aniline-type. The invention also relates to the production of said modified inorganic particles and to their use in thermoplastics and duroplastics.

Abstract: A process for purifying gaseous melamine containing ammonia is provided. The method comprises partly condensing the gaseous melamine-containing ammonia to form melamine in liquid NH3 and purified NH3 gas. The melamine and purified NH3 gas are taken off.

Abstract: A process for preparing melamine by pyrolysis of urea in a high-pressure process, in which urea is reacted together with NH3 to give melamine and the melamine melt formed is fed together with further urea to a cooling reactor, with the melt being cooled to a temperature which is 1-50° C., preferably 1-30° C., above the melting point of the melamine, which is dependent on the prevailing NH3 pressure. Introduction of NH3 in countercurrent drives out the CO2 formed, after which the melamine melt is worked up in any appropriate way.

Abstract: Polymers are prepared from A) 60 to 95 percent by weight of a mixture including A1) 20 to 70 percent by weight of hydroxyalkyl amino triazines and A2) 30 to 80 percent by weight of bis(hydroxyalkyl) amino triazines B) 5 to 40 percent by weight of polyfunctional compounds selected from one or more of B1) polyisocyanates and/or oligomeric polyesters or polyethers with isocyanate end groups, B2) aliphatic dicarboxylic acids, esters, chlorides or anhydrides, or aromatic polybasic acids, esters, chlorides or anhydrides, B3) aliphatic or aromatic diglycidal compounds or triglycidyl compounds, and, optionally, C) 1 to 20 percent by weight of aliphatic, cycloaliphatic or aromatic dihydroxy compounds, polyalkylene glycols and aliphatic aldehydes.

Abstract: Mixtures of triazine derivatives free from polyalkylene oxide Mixtures of triazine derivatives free from polyalkylene oxide are produced from 20 to 70 percent by weight of triazine derivatives with hydroxyalkyl amino groups and 80 to 30 percent by weight of triazine derivatives with bis(hydroxyalkyl) imino groups by catalytic reaction of alkylpropylene oxides with triazine derivatives at a melamine derivative/alkylpropylene oxide molar ratio of 1:1.5 to 1:10 in the presence of metal alkyls, metal hydrides, metal alcoholates and/or metal alkylamides as catalysts. The triazine derivative/hydroxy group mixtures free from polyalkylene oxide are particularly suited for producing plastic materials, flame retardants, additives, pharmaceuticals, textile auxiliaries, and paints or finishes.

Abstract: A process for the production of melamine by pyrolysis of urea in a high-pressure reactor having a vertical central pipe is provided. The melamine flows upwards into the reactor from below, mixes in the lower part of the reactor with a urea melt, and optionally NH3, introduced into the reactor from below, and emerges from the central pipe in the upper part of the central pipe. Part of the melamine formed flows downward in the annular space between the central pipe and reactor wall, and the remainder is expelled for further work-up. The off-gases are removed at the top of the reactor. A reactor for carrying out the process is also provided.

Abstract: The invention relates to a method for producing pure melamine. According to this method, the melamine melt, which is produced from urea in a high-pressure process, is cooled and ammonia is added until it reaches a temperature of approximately 1 to 50° C. above the melting temperature of the melamine as dependent on the respective pressure of ammonia and then either a) quenched with water or an aqueous solution or suspension containing ammonia and/or melamine so that the melamine solidifies or b) quenched with cold liquid or gaseous ammonia, so that the melamine solidifies, the melamine then being cooled further with water or an aqueous solution or suspension containing ammonia and/or melamine and c) the melamine is then isolated.

Abstract: The invention relates to a method for producing solid melamine by expanding liquid, ammoniacal melamine which is mixed with excess ammonia, whereby a dispersion is produced. Said dispersion is expanded, optionally after it has been held under ammonia pressure, whereby solid melamine is deposited. The solid melamine is optionally held under ammonia pressure. Expansion is then optionally carried out in any particular order, along with cooling to room temperature and the pure melamine is isolated.

Abstract: The invention relates to a method for producing urea. According to said method, the off-gases which originate from a melamine plant and essentially consist of NH3 and CO2 are introduced into the high-pressure zone of the urea plant by means of ejectors.

Abstract: Mixtures of triazine derivatives free from polyalkylene oxide are produced from 20 to 70 percent by weight of triazine derivatives with hydroxyalkyl amino groups and 80 to 30 percent by weight of triazine derivatives with bis(hydroxyalkyl) imino groups by catalytic reaction of alkylpropylene oxides with triazine derivatives at a melamine derivative/alkylpropylene oxide molar ratio of 1:1.

Abstract: Polymers made from triazine derivatives for intermediates and molded materials with improved toughness and high flame resistance and strength consisting of

Abstract: The invention relates to a method for purifying melamine in which impure melamine is heated to a temperature range above 325°C. but lower than the melting point of melamine which depends on the prevailing ammonia pressure. In addition, the impure melamine is held in said temperature range under an ammonia pressure ranging from 1 to 150 bar for a duration lasting from 1 minute up to 20 hours. The melamine is provided in solid form. Afterwards, the melamine is relieved from pressure and cooled in any order.

Abstract: Process for cooling liquid melamine by mixing with solid melamine or with solid inert substances or with a mixture of solid melamine and solid inert substances.

Abstract: Modified melamine-formaldehyde resins are made of a condensate of formaldehyde, urea, melamine and modifying agents which contains: (a) a combination of 5 to 25 wt %, with respect to melamine, of dicyanodiamide and 8 to 30 wt %, with respect to melamine, of water-soluble polyalcohol with at least two hydroxyalkyl groups, and/or (b) 1.5 to 20 wt % amines having the formulas (Ia)NR.sub.4 R.sub.5 --R.sub.1 --X (Ia)and/or (Ib),NR.sub.4 R.sub.5 --R.sub.2 --Y--R.sub.3 --X (Ib)in which R.sub.1 and R.sub.3 are the same or different and depending on the meaning of X stand for a linear, branched or cyclic C.sub.1 -C.sub.12 alkyl or alkylene radical and R.sub.2 stands for a linear, branched or cyclic C.sub.1 -C.sub.12 alkylene radical; R.sub.4 and R.sub.5 can be the same or different and can stand for H or for a linear or branched C.sub.1 -C.sub.12 alkyl radical; and X can stand for hydrogen, OH or NR.sub.4 R.sub.5 and Y can stand for --O-- or --NH--. The molar ratio of melamine to formaldehyde ranges from 1:1.

Abstract: Process for the production of highly pure melamine in which an aftertreatment of the melamine is carried out, comprising the stepsa) separating off the NH.sub.3 /CO.sub.2 gas mixture from the liquid melamine, if appropriateb) reducing the CO.sub.2 dissolved in the liquid melamine by introducing gaseous ammoniac) allowing the liquid melamine to remain for a mean residence time of 0 to 8 hours at a temperature between 430.degree. C. and the melting point of melamine and an ammonia partial pressure of 50 to 400 bar andd) slow, controlled cooling by lowering the temperature from the temperature present in a), b) respectively c) to 330.degree. to 270.degree. C. at a cooling rate of up to 150.degree. C.