MXPA01009409A - Flame-retarding composition and process for the preparation thereof - Google Patents

Abstract

Flame-retarding composition comprising:10 - 90 wt.%melem, 0.01 - 30 wt.%melam, 0.01 - 15 wt.%melamine, 0.1 - 65 wt.%higher condensation products of melamine and/or melem, the volatiles content being lower than 3 wt.%and the sum of the individual components amounting to 100 wt.%. Also a process for the preparation of a flame-retarding composition comprising 10 - 90 wt.%melem, 0.01 - 30 wt.%melam, 0.01 - 15 wt.%melamine and 0.1 - 65 wt.%higher condensation products of melamine and/or melem, the volatiles content being lower than 3 wt.%, by heating melamine-containing starting product for more than 0.1 second, for example by passing it through a heating zone, at a temperature of 350 - 800°C and a pressure of between 1 KPa and 50 Mpa. The invention also relates to polymer compositions containing the flame-retarding composition.

Description

COMPOSITION OF FLAME DELAY AND PROCEDURE FOR THE PREPARATION OF THE SAME DESCRIPTIVE MEMORY The invention relates to a flame retardant composition and to a process for the preparation thereof. A flame retardant composition and a process for the preparation thereof are described, for example, in Japanese Patent Publication JP 59-45352, in which the melamine melamine and melon condensation products are prepared and used as flame retardants. Flame in polyamide compositions. In this publication melem is prepared by melamine heating at a temperature of 400-500 ° C for several hours. Melon is prepared by heating melamine at 500 - 550 ° C until no more ammonia is released. JP 59-45352 mentions that the decomposition temperature of melem remains above 500 ° C and that that of melon is higher than 600 ° C. This means that melem and melon have a particularly good thermal stability. According to JP 59-45352, the nitrogen content of both components is above 60%, as a result of which the substances are not combustible. JP 59-45352 also mentions that other known flame retardants can also be used in combination with melem or melon, for example melamine, cyanuric acid, melamine ciarunate. JP 59-45352 does not mention the composition of the product obtained. Melamine and its condensation products all have a characteristic thermal degradation curve. This means that melamine and its condensation products decompose at a certain temperature to form products containing nitrogen. These nitrogen-containing products that are released in thermal degradation play an important role in the flame retardant behavior. To obtain a good flame retardant behavior in polymers it may be favorable to combine flame retardant components, such as melem or melon, and the main condensation products of melamine and / or melem, which have different degradation characteristics, in a unique composition. The advantage of this is that, regardless of the temperature prevailing in a fire, there is always a component present that degrades at the prevailing temperature and produces enough nitrogen-containing components that have a flame retardant effect. However, if the flame retardant composition contains volatile components, such as urea and / or water, these will have a negative effect on the processing properties when the compositions are used in polymers with a high melting temperature, for example in polyesters. such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or in polyamides. Said negative effect can be the foaming during the extrusion or the formation of deposits on the mold in the injection molding. If the flame retardant composition contains too high a concentration of the main melamine and / or melem condensation products, the composition will be yellow, which is undesirable in the case of processing in (colorless) polymer compositions. The use of pure melamine condensation products such as melam or melem or pure melon as a flame retardant in polymers is not favorable because this will usually be difficult, and therefore costly, to prepare pure compounds and because that the pure components only have one mode of degradation and therefore will work optimally only in a limited temperature range. The Applicant has discovered that excellent processing properties and excellent flame retardation properties and color properties can be obtained in polymer compositions by using a flame retardant composition containing: 10-90% by weight melem, 0.01-30% by weight of melam, 0.01 - 15% by weight of melamine 0.1 - 65% by weight of the main condensation products of melamine and / or melem, the concentration of volatile components being below 3% by weight and the sum of the individual components amounting to 100% by weight. The concentration of the volatile components is defined herein as the decrease in weight that occurs upon heating the flame retardant compositions from room temperature to 300 ° C in a TGA (TGA = thermogravimetric analysis) measurement to a heating interval of 200. ° C per minute. The Applicant has also found a method for preparing a flame retardant composition comprising 90% by weight of melem, 0.01-30% by weight of melam, 0.01-15% by weight of melamine, 0.1-65% by weight of the main condensation products of melamine and / or melem, the concentration of volatile components being below 3% by weight and the sum of the individual components amounting to 100% by weight, upon heating an initial product containing melamine, for example to the passing it through a heating zone, for a time greater than 0.1 seconds, preferably 1 second to 400 minutes, in particular 2 seconds to 300 minutes, at a temperature of 350-800 ° C, preferably between 375 and 600 ° C and a pressure between 1 Kpa and 50 Mpa, preferably between atmospheric pressure and 30 Mpa, more in particular between the atmospheric pressure and 15 Mpa. Examples of heating zones are heating zones of the type found in extruders, such as single and two-screw extruders.; autoclaves; turbo mixers; mixers with cutting knives; stirring mixers; turbulence mixers; mixers with rubber knives; mixing extruders; continuous and discontinuous kneading machines; kilns with rotary drums etc.

A mixture of melamine, melem, melam and major condensation products of the melamine and / or melem may optionally be obtained by treating the heating product further, to obtain a flame retardant composition comprising 10-90 wt.% Melem, 0.01-30% by weight of melam, 0.01-10% by weight of melamine, 0.1-65% by weight of the main condensation product of melamine and / or melem, the concentration of the volatile components being below 1% by weight weight and the sum of the individual components amounting to 100% by weight. This additional treatment is preferably washed with water to dissolve and remove from the flame retardant composition a portion of the melamine and / or other water soluble components. As a starting material for the present process, virtually pure melamine can be used, as for example obtained from a gas phase melamine factory operating continuously where the melamine is purified by crystallization. A method for the preparation of melamine via a gas phase process for example is known from US-A-3210352. However, this high degree of purity is not necessary. Melamine contaminated with melam and / or melem and / or the main melamine and / or melem condensation products can optionally be used as the starting material, for example the product that is formed during the start of the melamine factory or the melamine of the type that is prepared in the gas phase melamine factory before the average crystallization purification takes place or the melamine contaminated with melam and / or melem and / or the main melamine condensation products and / or melem formed from some another way. It is also possible to use melamine obtained in a liquid phase process as starting material. A known process for the preparation of melamine via a liquid phase process is described in US-A-4565867, from which it is known that the degree of purity is less than that of the product of a gas phase process; in particular, its content in melam is greater. The contaminants such as residual catalysts, ureidomelamine and / or guanidine carbonates can also be present without any objection. Oxygen-containing trypsin compounds such as amelin, amelide and / or cyanuric acid will also be present up to 5% by weight without any objection. The remnants of the starting materials used for the preparation of melamine, such as urea and / or dicyan diamine, may also be present; the dicyan diamine may be present in an amount greater than 10% by weight without any objection, while the melamine may contain up to 30% by weight of urea. The starting material for the present process may also contain contaminants containing a mixture of urea, oxygen-containing trypsin compounds, dicyanodiamide, guanidine carbonate, ureidomelamine and residual catalyst. In a preferred embodiment of the invention the flame retardant composition is prepared by heating start products containing melamine in an autoclave or in an extruder. Preferably at a pressure between atmospheric pressure 20 Mpa, at a temperature of 350-625 ° C and with residence time between 0.1 seconds and 360 minutes. More particularly, the heating of the starting product containing melamine is carried out in an extruder with a residence time in the extruder of between 0.1 seconds and 60 minutes. The invention also relates to flame retardant polymer compositions comprising the following components: a. 65-95% by weight of the composition containing polymer b. 5-35% by weight of the flame retardant composition according to the invention. The flame retardant composition according to the invention is particularly suitable for use in polymer compositions requiring heat-resistant flame retardants., for example in polyamides, polyimides, polyesters, styrene-containing polymers, epoxy resins, unsaturated polyester resins, and polyurethanes. Examples of polyamides are polyamides and copolyamides derived from diamines and dicarboxylic acids and / or from amino carboxylic acids or the corresponding lactams, such as polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9 , 6/12, 4/6, 66/6, 6/66, polyamide 11, polyamide 12, (co) partially aromatic polyamides, for example polyamides based on an aromatic diamine and adipic acid; polyamides prepared from alkylene diamine and iso and / or teraphthalic acids and copolyamides thereof, copolyether amides, copolyester amides, etc.

Examples of polyesters are derivatives of polyesters from dicarboxylic acids and dialcohols and / or from hydroxycarboxylic acids or the corresponding lactones such as polyethylene terephthalate, polybutylene terephthalate, poly-1,4-dimethylolcyclohexane terephthalate, polyhydroxybenzoates, polycaprolactone and copolyesters thereof, copolyether esters, etc. Examples of styrene-containing polymers are polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymers and mixtures thereof. Preferably the flame retardant composition is used in polyesters such as polyethylene terephthalate and / or polybutylene terephthalate, polybutylene terephthalate being particularly preferable, or in polyamides such as nylon-6, nylon 6,6 or nylon 4,6. "Compositions containing polymers" are understood as compositions which, in addition to the polymer, may contain reinforcing agents and / or fillers, compounds having a synergistic effect with the flame retardant composition, other flame retardant components than those in accordance with the invention, plus the usual additives. If the reinforcing agents and / or fillers are used in the polymer composition of the invention, their concentration can vary within a wide range, partially determined by the level of mechanical properties one wishes to achieve. In general, the concentration of the reinforcing agents will not be greater than 50% by weight in the reinforced flame retardant polymer composition. Preferably the reinforced flame retardant polymer composition will contain 5-50% by weight of reinforcing agents, more preferably 15-45% by weight. The reinforcing agents can be chosen from the group comprising inorganic reinforcing agents, such as mica, clay, talc or glass fibers, or aramid fibers and / or carbon fiber. However, glass fibers are preferred. The flame retardant effect of the flame retardant composition according to the invention can be reinforced by the presence of a compound having a synergistic effect with the flame retardant composition, such as a carbon-forming compound, whether or not it is combined with a catalyst that promotes the formation of carbon. In general, the concentration of the flame retardant composition can be chosen to be lower. In principle, all known substances that reinforce the effects of flame retardant compositions can be used as carbon-forming compounds. Examples are phenolic resins, epoxy resins, melamine resins, alkyd resins, allyl resins, unsaturated polyester resins, silicone resins, urethane resins, acrylate resins, polyphenylene ether, polycarbonate, starch, glucose and compounds containing at least two hydroxyl groups. Examples of compounds containing at least two hydroxyl groups are alcohols containing at least two hydroxyl groups, for example pentaerythritol, dipentaerythritol, tripentaerythritol and mixtures thereof. The concentration of the carbon-forming compound having a synergistic effect with the flame retardant in the general polymer composition will generally be between 0 and 30% by weight, preferably between 1 and 20% by weight. As the catalyst that promotes the formation of carbon, for example, metal salts of tungstic acid can be used; a tungsten acid oxide complex with a metalloid; tin oxide salts; ammonium sulphamate and / or the dimers thereof. The metal salts of tungstic acid are preferably alkali metal salts of tungstic acid, in particular sodium tungstate. A "acid tungsten oxide complex with a metalloid" is understood to be a complex of acid oxides which are formed from a metalloid such as silicone or phosphorus and tungsten, such as silicotungstic acid or phosphorotungstic acid. The amount of catalyst that promotes the formation of carbon that is used in the general polymer composition is 0.1-5% by weight, preferably 0.1-2.5% by weight. The flame retardant effect of the flame retardant composition according to the invention can be further enhanced by using one or more other flame retardant components. In principle, all known flame retardants can be used like the other flame retardant components. Examples are antimony oxide, for example antimony trioxide, combined with halogen compounds; alkaline earth metal oxides, for example zinc oxide, magnesium oxide; other metal oxides, for example albumin, silica, iron oxide and manganese oxide; metal hydroxides, for example magnesium hydroxide and aluminum hydroxide; metal borates, for example zinc borate, whether or not hydrated; and phosphorus-containing compounds. Examples of phosphorus containing compounds are zinc phosphate, ammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate, phosphate ethylenediamine phosphate, piperazine pyrophosphate, piperazine phosphate, melamine, dimelamine phosphate, melamine pyrophosphate, melamine polyphosphate, phosphate, melam pyrophosphate, melam polyphosphate, melam phosphate, melem pyrophosphate, melem polyphosphate, melem polyphosphate, guanidine phosphate, phosphate dicyanodiamide phosphate, urea and phosphates, pyrophosphates and polyphosphates main condensation products of melamine and / or melem and mixtures of these phosphates. Acids, salts, mixed acid salts, esters, partial esters and mixed esters of phosphates can also be used. It is also possible to make use of phosphine oxides, phosphine sulphides and phosphors and phosphonates, phosphines and phosphinates and their acids, salts, mixed acid salts, esters, partial esters and mixed esters. The concentration of other flame retardant components that can be used can vary within a wide range but will generally not be greater than the concentration of the flame retardant composition according to the invention. Preferably the amount will be between 0 and 35% by weight, more in particular 1 and 20% by weight. Preference is given to using phosphates, phosphinates and phosphonates. Examples of compounds are described, for example, in Kirk Othmer, Encyclopedia of Chemical Technology, volume 10, pp. 396-419 (1980). Well-known examples are: the esters of trimethylol propane and methyl phosphonic acid, ethyl-methyl-phosphinic acid and the aluminum salt of ethyl-methyl-phosphinic acid. Many of the compounds mentioned herein can also promote carbon formation. Other known compounds present in flame retardant compositions as polytetrafluoroethylene may also be present. The polymer composition may also contain other usual additives, as heat and UV stabilizers, mold release agents, plasticizers, softeners, lubricants, dispersing agents, colorants and / or pigments, in amounts generally used for these additives while the properties are not adversely affected. The polymer composition according to the invention can be prepared using conventional techniques known per se, as by mixing all or some of the components in dry condition in a drum mixer, followed by melting in a melt mixer, for example a Brabender mixer or a worm or twin worm extruder or a kneading machine. Preferably a doubleworm extruder is used. The various components of the composition of the polymer of the invention can be dosed together at the inlet of the extruder. These can also be dosed to the extruder in different places. Some of the components, for example dyes, stabilizers, flame retardant composition, compounds having a kinetic effect with the flame retardant composition and / or other flame retardant components can for example be added to the polymer in the form of a master batch The polymer composition according to the invention can be processed into semi-finished products or finished products using techniques known to a person skilled in the art, for example injection molding. The invention will be further elucidated with reference to the following examples: COMPARATIVE EXAMPLE A The melamine (product of a gas phase process from DSM) was dosed to a co-rotator double worm extruder (Werder &Pfleíderer, type ZSK 30/33) at a ratio of 3 kg per hour. The cylinder temperature had been set at 330 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 115 seconds. The solid mixture left by the extruder was white and had the following composition: 88% by weight of melamine, 6% by weight of melam, 2% by weight of melamine and 4% by weight of the main melamine condensation products and / or melem. The content of volatile elements is 1.6% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC). The values obtained have a relative error of 5% or less.

EXAMPLE 1 The melamine (product of a gas phase process from DSM) was dosed to a co-rotator doubleworm extruder (Werder &Pfleiderer, type ZSK 30/33) at a rate of 1 kg per hour. The cylinder temperature had been set at 400 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 115 seconds. The solid mixture left by the extruder was white and had the following composition: 8% by weight of melamine, 0.5% by weight of melam, 73% by weight of melamine and 18.5% by weight of the main melamine condensation products and / or melem. The content of volatile elements is 0.4% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC). The values obtained have a relative error of 5% or less.

EXAMPLE 2 The melamine (product of a gas phase process from DSM) was dosed to a co-rotator doubleworm extruder (Werder &Pfleiderer, type ZSK 30/33) at a rate of 2 kg per hour. The cylinder temperature had been set at 450 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 115 seconds. The solid mixture left by the extruder was white and had the following composition: 1.3% by weight of melamine, 0.1% by weight of melam, 64% by weight of melamine and 23.7% by weight of the main melamine condensation products and / or melem. The content of volatile elements is 0.1% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC). The values obtained have a relative error of 5% or less.

EXAMPLE 3 The melamine (product of a gas phase process from DSM) was dosed to a co-rotator doubleworm extruder (Werder &Pfleiderer, type ZSK 30/33) at a ratio of 3 kg per hour. The cylinder temperature had been set at 450 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 115 seconds. The solid mixture left by the extruder was white and had the following composition: 1% by weight of melamine, 0.1% by weight of melam, 86% by weight of melamine and 12.9% by weight of the main melamine condensation products and / or melem. The content of volatile elements is 0.2% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC). The values obtained have a relative error of 5% or less.

EXAMPLE 4 1008 grams (8 moles) of melamine were introduced into an autoclave with a volume of about 2000 ml. Agitation was started at a speed of approximately 30 rpm. The reactor was then brought to the required temperature. The reaction temperature was 500 ° C. The ammonia pressure in the autoclave, which occurred during the reaction, was maintained at approximately 2 Mpa with the help of a control valve. The reaction time was 60 minutes. Then the autoclave cooled. The pressure in the autoclave was maintained during cooling. The ammonia pressure was released as soon as the temperature dropped below 200 ° C. The solid mixture left by the autoclave was white to pale beige and had the following composition: 0.4% by weight of melamine, 0.5% by weight of melam, 91% by weight of melem and 8% by weight of the main condensation products of melamine and / or melem. The content of volatiles was 0.1% by weight. The composition of the flame retardant composition was determined by the aid of high pressure liquid chromatography (HPLC).

EXAMPLE 5 A co-rotating twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 2 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.1 Gpa and the elongation at break was 2.0% (ISO 527/1).

EXAMPLE 6 A co-rotating twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 3 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.0 Gpa and the elongation at break was 2.0% (ISO 527/1).

EXAMPLE 7 A co-rotating twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 4 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.2 Gpa and the elongation at break was 2.1% (ISO 527/1).

EXAMPLE 8 A twin co-rotating worm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polyamide 6, 20 parts of fiberglass, 30 parts of base product of example 4 and 5 parts Antiblaze® 1045 (phosphonate cyclic ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 11.2 Gpa and the elongation at break was 2.0% (ISO 527/1).

EXAMPLE 9 A twin-co-rotator worm extruder (Werder &Pfleiderer, type ZSK 25/38) was fed with: 80 parts of polyamide 4, 6 and 20 parts of base product of example 3. The temperature of the cylinder was set at 300.degree. 315 ° C and the screw speed at 270 rpm. Specimens with a thickness of 1.6 mm were produced from the obtained compound and evaluated. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 3.6 GPa and the elongation at break was approximately 25% (ISO 527/1).

EXAMPLE 10 A twin-co-rotator worm extruder (Werder &Pfleiderer, type ZSK 25/38) was fed with: 90 parts of polyamide 4, 6 and 10 parts of base product of example 3. The cylinder temperature was set at 300.degree. 315 ° C and the screw speed at 270 rpm. Specimens with a thickness of 1.6 mm were produced from the obtained compound and evaluated. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 2.3 GPa and the elongation at break was approximately 30% (ISO 527/1).

EXAMPLE 11 A twin-co-rotator worm extruder (Werder &Pfleiderer, type ZSK 25/38) was fed with: 80 parts of polyamide 6, 6 and 20 parts of base product of example 3. The temperature of the cylinder was set at 270.degree. 280 ° C and screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the obtained compound and evaluated. The burn behavior in accordance with UL 94 was V-0.

EXAMPLE 12 A twin-co-rotator worm extruder (Werder &Pfleiderer, type ZSK 25/38) was fed with: 80 parts of acrylonitrile-butadiene-styrene (Ronfalin® from DSM containing 20 parts of rubber) and 20 parts of base product of example 3. The temperature of the cylinder was set at 180-210 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the obtained compound and evaluated. The burn behavior in accordance with UL 94 was V-0.

EXAMPLE 13 A mixture of 98.0% melamine, 0.81% urea, 0.03% CO2, 0.05% impurities related to amelina (such as amelina, amelido, cyanuric acid and uridomelamine) and 0.07% organic solids (melem, melam, and others) oxygen-free compounds), as obtained in the process according to US4565867, were dosed to a co-rotator double worm extruder (Werder &Pfleiderer, type ZSK 30/33) at a rate of 8 kg per hour. The cylinder speed had been set at 450 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 110 seconds. The solid mixture left by the extruder was white to pale beige and had the following composition: 7% by weight of melamine, 2% by weight of melam, 76% by weight of melem, 14% by weight of the main condensation products of melamine and / or melem, and an unidentified residual fraction of about 1% by weight. The content of volatiles is 0.2% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC).

EXAMPLE 14 A co-rotating twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 13 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.0 Gpa and the elongation at break was 2.4% (ISO 527/1).

EXAMPLE 15 The melamine with a purity of 99.92% was obtained in the process according to US3210352 and dosed to a co-rotator double worm extruder (Werder &Pfleiderer, type ZSK 30/33) at a rate of 8 kg per hour. The cylinder speed had been set at 450 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 110 seconds. The solid mixture left by the extruder was white to pale beige and had the following composition: 6% by weight of melamine, 1% by weight of melam, 77% by weight of melem, 16% by weight of the main condensation products of melamine and / or melem. The content of volatiles is 0.3% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC).

EXAMPLE 16 A co-rotating twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 15 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.5 MPa and the elongation at break was 2.2% (ISO 527/1).

EXAMPLE 17 A mixture of 98.7% melamine, 1.0% urea, 0.06% CO2, 0.1% compounds related to amelina (such as amelina, amelido and cyanuric acid) and 0.12% organic solids (melem, melam, and other compounds) and 0.02% (200 ppm) of residual inorganic catalyst, as obtained after the extinction and before the crystallization step in accordance with the procedure described in US3210352, were dosed to a co-rotator doubleworm extruder (Werder &; Pfleiderer, type ZSK 30/33) at a speed of 8 kg per hour. The cylinder speed is set at 450 ° C and the screw speed at 40 rpm. The residence time of the components dosed in the extruder was 110 seconds. The solid mixture left by the extruder was white to pale beige and had the following composition: 6% by weight of melamine, 1% by weight of melam, 74% by weight of melem, 20% by weight of the main condensation products of melamine and / or melem. The content of volatiles is 0.3% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC).

EXAMPLE 18 A co-rotator twinworm extruder (Werder &Pfleiderer, type ZSK 30/33) was fed with: 45 parts of polybutylene terephthalate, 30 parts of fiberglass, 15 parts of basic product of example 17 and 10 parts of Antiblaze® 1045 (cyclic phosphonate ester from Albright &Wilson). The cylinder temperature had been set at 250 ° C and the screw speed at 200 rpm. Specimens with a thickness of 1.6 mm were produced from the compound obtained and tested. The burn behavior in accordance with UL 94 was V-0. The modulus of elasticity was 10.2 Gpa and the elongation at break was 2.0% (ISO 527/1).

EXAMPLE 19 The melamine (product of a gas phase process from DSM) was dosed to a co-rotator doubleworm extruder (Werder &Pfleiderer, type ZSK 30/33) at a rate of 1 kg per hour. The cylinder temperature had been set at 400 ° C and the screw speed at 40 rpm. The residence time of the components dosed to the extruder was 95 seconds. The solid mixture left by the extruder was a base mixture. The base product was washed in proportions of about 200 grams in 3 liters of water at about 90 ° C. After 15 minutes the hot runner was removed through filtration. The residue was treated three or more times according to the same procedure. The washed product was finally dried at 120 ° C in a vacuum drying oven until it contained less than 1% by weight of water. The product thus obtained was white and had the following composition: 1% by weight of melamine, 2% by weight of melam, 77% by weight of melamine and 20% by weight of the main condensation products of melamine and / or melem. The volatile content is less than 0.3% by weight. The composition of the flame retardant composition was determined with the aid of high pressure liquid chromatography (HPLC).

Claims (11)

NOVELTY OF THE INVENTION CLAIMS

1. - A flame retardant composition comprising 10-90 % by weight of melam, 0.01-30% by weight of melam, 0.01-15% by weight of melamine, 0.1-65% by weight of the main condensation products of melamine and / or melem, the volatile content being below of 3% by weight and the sum of the individual components amounting to 100% by weight.

2. The process for the preparation of a flame retardant composition, further characterized in that the flame retardant composition comprises 10-90% by weight of melem, 0.01-30% by weight of melam, 0.01-15% by weight of melamine, 0.1-65% by weight of the main condensation products of melamine and / or melem, the content of volatiles being below 3% by weight and the sum of the individual components amounting to 100% by weight, is prepared when heating an initial product containing melamine for more than 0.1 seconds at a temperature of 350 - 800 ° C and at a pressure between 1 KPa and 50 MPa.

3. A process according to claim 2, further characterized in that the starting product containing melamine is heated in an autoclave or extruder.

4. - The method according to claim 2, further characterized in that the starting product containing melamine is heated in an extruder with a residence time in the extruder of between 0.1 seconds and 60 minutes.

5. The process according to any of claims 2 - 4, further characterized in that the flame retardant composition is subsequently washed with water, causing a division of the melamine and any other water soluble component to be dissolved and removed to from the flame retardant composition.

6. The process according to any of claims 2 - 5, further characterized in that the melamine is contaminated with melam and / or melem and / or the main condensation products of the melamine and / or melem which are used as products of start.

7. A method according to any of claims 2 - 5, further characterized in that as a starting product, use is made of the product that is formed during the start of a melamine or melamine factory as prepared in a phase factory gas before any crystallization takes place.

8. The process according to any of claims 2 - 5, further characterized in that the melamine obtained by the liquid phase process is used as the starting product.

9. - The flame retardant polymer composition comprising the following components: a. 65-95% by weight of the polymer-containing composition b. 5-35% by weight of the flame retardant composition according to claim 1.

10. A flame retardant polymer composition according to composition 9, further characterized in that the composition also comprises reinforcing fibers.

11. The object produced from the composition of the flame retardant polymer according to claim 9 or claim 10.