WO2001077088A1

WO2001077088A1 - Methanesulfonic acid melam, process for producing the same, and flame-retardant polyamide resin composition

Info

Publication number: WO2001077088A1
Application number: PCT/JP2001/002501
Authority: WO
Inventors: Masaaki Ozawa; Yuuko Furuya; Akira Yoshida
Original assignee: Nissan Chemical Industries, Ltd.
Priority date: 2000-04-06
Filing date: 2001-03-27
Publication date: 2001-10-18
Also published as: JP2001288361A; JP4569721B2

Abstract

A methanesulfonic acid melam which can be advantageously used as a flame retardant for synthetic resins, especially polyamide resins; and a flame-retardant polyamide resin composition containing the methanesulfonic acid melam. The methanesulfonic acid melam is obtained by burning a production of the reaction of melamine with methanesulfonic acid at 300 to 400°C for 0.1 to 30 hours. It has a solubility in water (25°C) of 0.01 to 0.10 g/100 ml, gives a 10 wt.% aqueous slurry thereof having a pH (25°C) of 3.0 to 7.0, and contains melam in an amount of 0.90 to 1.30 mol per mol of the sulfur atoms.

Description

Description Melam methanesulfonate, method for producing the same, and flame-retardant polyamide resin composition

Technical field

TECHNICAL FIELD The present invention relates to melam methanesulfonate, a method for producing the same, and a flame-retardant polyamide resin composition using the same. Melam methanesulfonate is suitably used as a flame retardant for synthetic resins, especially polyamide resins.

Background art

Regarding salts of melamine and sulfur-containing acids, Japanese Patent Application Laid-Open No. H08-231151 discloses a water-resistant aminotriazine sulfate composition containing melamine and sulfuric acid. The method describes a method for producing a melamin sulfate composition characterized in that the reaction is carried out at a molar ratio of 1: 0.1 to 1. Regarding the calcined products of sulfuric acid and melamin, see the American Chemical Society Symposium Series No. 425 “Fire and Polymers” (ACS Symposium Series No. 425 “Fire and Polymers”), Chapter 15; 2 11 1-238 (American Chemical Society, Washington, DC, Washington, DC, published in 1990) It is described that dimemyl pyrosulfate is produced by heating (melaminio atom = 11 (molar ratio)) at 300 to 400 ° C.

As a salt of a 1,3,5-triazine derivative containing melam and an inorganic acid, WO98 / 93936 (corresponding Japanese Patent Application Publication: Japanese Patent Application Laid-Open No. 10-306801) ), The reaction product obtained by mixing melamine and phosphoric acid at a molar ratio of 1: 2.0 to 4.0 is calcined at 340 to 450 ° C to obtain polylinol. A method for producing the acid melamin 'Melam' melem double salt is described. In addition, W09 839 9307 (corresponding Japanese Patent Application Publication: Japanese Patent Application Laid-Open No. 10-36082) discloses that melamin, phosphoric acid and sulfuric acid are mixed at a specific ratio. Baking the resulting reaction product at 340 to 400 ° C to produce melamin melam, a polyacid composed of phosphorus, zeolite and oxygen Is disclosed.

WO 96/16 948 (Japanese Patent Application Laid-Open No. 10-511409) discloses a process for producing melam, which is one of the condensed products of melamin, by using melamine. And a method of heating a mixture of paratoluenesulfonic acid, which is one of the organic acids, at 250 to 350 ° C. to obtain a melam salt of the acid and purifying the melam salt. However, the para-toluenesulfonic acid melam salt obtained in the heating stage of this method exhibits a strong dark brown color, which limits the toning when used as an additive in synthetic resins, for example. Melam methanesulfonic acid obtained by calcining the reaction product of melamine and methanesulfonic acid has not been reported so far.

Flame retardation of polyamide resin is generally performed by a method of adding a halogen compound or a nitrogen compound. However, when a halogen-based compound is used, the mold may be corroded due to the generation of corrosive gas during molding, and there is also a problem that toxic halogenated gas is generated during combustion. Therefore, a flame retardant that does not use a halogenated compound has attracted attention.

As typical nitrogen-based flame retardants which are non-halogen-based polyamide resins, refer to Japanese Patent Application Laid-Open No. 53-31959 (corresponding US patents: US Pat. Nos. 4,298,559). A method using melamine cyanurate disclosed in US Pat. WO 966/17013 (Japanese Patent Application Laid-Open No. 10-59099) discloses that the use of a resin, especially a polyamide resin having a melting point of 260 ° C. or more, is difficult. Methods for use as a fuel have been disclosed. However, although these methods show a high level of flame retardancy to unreinforced polyamide resin, the test specimens were subjected to a typical flame retardancy test, UL-94 Vertical Combustion Test of Underwriters Laboratories. Although the cotton installed below does not ignite, there is a problem that molten dripping (drip phenomenon) occurs. In recent years, the tendency of synthetic resins to become flame-retardant is increasing, and the development of a flame-retardant formulation that does not melt and drip during combustion is desired. Furthermore, when these nitrogen-based flame retardants are used in polyamide resins reinforced particularly with inorganic fillers such as glass fibers, it is difficult to exhibit a sufficient flame retardant effect. In the case of a reinforced polyamide resin at a higher molding temperature, these nitrogen-based flame retardants are easily decomposed and sublimated during molding, and the foaming phenomenon And mold contamination and the like. Disclosure of the invention

The nitrogen-based flame retardants disclosed in the above prior art are not sufficiently flame-retardant, especially with reinforced polyamide resins, and are liable to be decomposed and sublimated during molding to cause a foaming phenomenon and mold contamination. However, it is difficult to use it effectively as a flame retardant. An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to use methanesulfone as a starting material, which is made of melamin and methanesulfonic acid, which can withstand a wide range of uses as a flame retardant for polyamide resins. Disclosed is an acid melam and a method for producing the same. Further, the present invention provides a flame-retardant polyamide resin composition containing melam methanesulfonate. The method for producing melamne methanesulfonate of the present invention will be described.

0.0 1 Solubility of 0. l O gZ l OO ml in water (2 5 ° C), 3. 0~ 7. 0 with a 1 0 weight ⁰ 6 an aqueous slurry (2 5 ° C) The process for producing methansulfonate melam having a ratio of 0.90 to 1.30 moles of methan to pH and 1 mole of sulfur atoms is described in the following (a) and (b). Each process:

(a) Melamine and methanesulfonic acid are mixed in a ratio of 2.0 to 3.0 moles of melamine to 1 mole of methanesulfonic acid at a temperature of 0 to 200 ° C. Obtaining a reaction product by performing

(b) baking the reaction product obtained in the step (a) at a temperature of 300 to 400 ° C. for 0.1 to 30 hours,

Consists of

The methanesulfonic acid melan of the present invention has the general formula (1)

(CH ₃ S0 ₃ H) x (C ₆ H ₉ N _n ) y (1)

(However, C represents a carbon atom, H represents a hydrogen atom, S represents a sulfur atom, N represents a nitrogen atom, and X and y represent positive numbers, 0.90 yZx x 1. There is a correlation of 3.)

The melam is represented by the chemical formula C ₆ H ₉ Ni] (N—4,6-diamino;!, 3,5-triazine-12-yl) -11,3,5- Triazine 1, 2, 4, 6—Tri It is a family. This is a 1,3,5-triazine derivative in which one molecule of ammonia is desorbed and condensed from two molecules of melamin.

Furthermore, in the present invention, 1 to 100 parts by weight of the methane sulfonate of the present invention or 1 to 100 parts by weight of the methansulfonate is added to 100 parts by weight of the polyamide resin. Provided is a flame-retardant polyamide resin composition comprising 1 part by weight and 300 parts by weight of an inorganic filler. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a differential thermal analysis diagram of melam methanesulfonate obtained in Example 1. Explanation of symbols:

1 is a curve showing the results of differential thermal analysis (D T A).

2 ··· It is a curve showing the result of thermogravimetric analysis (TG). BEST MODE FOR CARRYING OUT THE INVENTION

Commercially available products such as melamin and methanesulfonic acid used in the step (a) of the present invention can be used. Methanesulfonic acid may be used as it is, or may be used as an aqueous solution having a methanesulfonic acid concentration of 50% by weight or more. In the present invention, mixing of the main laminate down and meta Nsuruhon acid, the main Rami down powder, under stirring, the meta Nsuruhon acid or meta Nsuruhon acid concentration 5 0 wt ^_0/0 or more main chest sulfonic acid solution Dry mixing or semi-dry mixing for addition and mixing is efficient and preferred. Also, the reaction product can be obtained by mixing in a slurry state in the presence of excess water, and filtering and drying the reaction product.

In the case of mixing melamine and methanesulfonic acid in the case of dry mixing or semi-dry mixing, a mixing / stirring device such as an automatic mortar, a universal mixer, a Henschel mixer, a Reedige mixer, and a homogenizer can be used. In order to make the mixing reaction more uniform, a Henschel mixer or a Lödige mixer having a shearing force is preferable. In the present invention, melamin and methanesulfonic acid are mixed in a ratio of 2.0 to 3.0 mol of melamin to 1 mol of methanesulfonic acid. Methanesulfonic acid 1 If the ratio of melamin is less than 2.0 moles relative to moles, it is not preferred because the acid of the calcined product obtained in the subsequent calcining step becomes excessive and the acidity becomes too strong. On the other hand, if the ratio of melamin exceeds 3.0 moles per mole of methanesulfonic acid, on the other hand, the residual amount of melamine in the final calcined product becomes too large or the volatilization of melamine during calcination becomes large. It is not preferable because it becomes too much.

When the melamine and methanesulfonic acid of the present invention are mixed, remarkable heat generation is recognized by reacting melamine and methanesulfonic acid to form a salt.

In the present invention, the temperature at the time of mixing melamine and methanesulfonic acid may be 0 to 200 ° C. In the case of removing moisture in the semi-dry mixing, the temperature is preferably 70 to 150 ° C. for efficient removal of moisture. Mixing under reduced pressure while suctioning with a suction pump or the like enables more efficient removal of water. The total time of mixing and stirring depends on the intensity of mixing, but is usually 10 minutes to 2 hours.

In the present invention, colloidal silica may be added at the time of mixing for the purpose of preventing caking during the subsequent firing or preventing adhesion to the firing machine, if necessary. Precipitated silica powder, fumed silica powder, colloidal silica that is a dispersoid of an aqueous silicic sol, and the like, preferably having a primary particle diameter of 100 nm or less. The amount of colloidal silica powder is preferably 10 to 10 parts by weight based on the total amount of melamine and methanesulfonic acid of 100 parts by weight. It may be added in a ratio.

In step (b) of the present invention, the mixed reaction product of melamine and methanesulfonic acid is mixed at a temperature of 300 to 400 ° C, preferably 320 to 380 ° C, for 0.1. By baking for up to 30 hours, preferably for 0.5 to 10 hours, melane methansulfonate can be obtained. The methanesulfonic acid melam obtained by the present invention is a white or slightly yellowish powder.

(b) By calcination in the step, melamin in the mixed reaction product undergoes a deammonification reaction to form melam, and finally from 0.90 to 1.3 per mole of sulfur atom. A melam methanesulphonate having a ratio of 0 mol is obtained. If the firing temperature is less than 300 ° C The melaninization reaction of melamine in the mixed reaction product is slowed down, and unreacted melamine tends to remain in the baked product. If the temperature exceeds 400 ° C., it is not preferable because methanesulfonic acid melam is decomposed. If the calcination time is less than 0.1 hour, the production of the target melamethane methanesulfonate is insufficient, and it may be longer than 30 hours, but if it exceeds 30 hours, it is not economical .

In the firing in the step (b) of the present invention, an electric furnace, a hot-air dryer, a single-tally kiln, a double-shaft-type stirring-type firing machine, a double-shaft-type kneader-type firing machine, a fluidized-flow firing furnace, or the like is used alone or in combination. Can be. By selectively removing the ammonia produced by the condensation of the melamine while suppressing the outflow due to the sublimation of the melamine during firing to some extent, the melamin can be efficiently converted to melam. Therefore, sintering with a porcelain-alumina sagger with a lid is preferred. More preferable is a baking furnace of the type that can be agitated for uniform baking. In particular, in the case of a double-shaft agitated baking machine or rotary kiln that can control the atmosphere, the sublimate of melamine is used. It is more preferable because it can be fired while returning the ammonia inside and discharging the generated ammonia to the outside of the system. The firing may be performed by either a batch method or a continuous method.

The desired melamine methanesulfonate can be obtained by the above calcination.However, when applied as a flame retardant for polyamide resin, the calcination product contains It is preferable not to leave unreacted melamine as much as possible. Melam methanesulfonate contains several weight percent of methanesulfonic acid salt of melem, which is formed by condensation of two molecules of melamine, which is a by-product, depending on the firing conditions. It may be done.

The melane methansulfonate obtained by the present invention has an extremely low solubility in water (25 ° C.) of 0.01 to 0.10 g Z 100 m 1, and thus has excellent water resistance. . It is characterized by having a pH of 3.0 to 7.0 as a 10% by weight aqueous slurry (at 25). Further, as shown in Example 1 later, according to TGZDTA analysis, it hardly decomposes up to 400 ° C, and is characterized by extremely excellent heat resistance.

Melamethane methanesulfonate, which is the calcined product of the present invention, may be used, if necessary, with a dry pulverizer such as a mixer, a pin disk mill, a ball mill, a dittoizer or the like. By pulverizing and classifying with a dry pulverizing classifier such as a centrifugal mill or an inomaizer, a preferred average particle diameter (median diameter) is 2 μm or less, more preferably an average particle diameter (median diameter) 10. It can be a fine powder of μm or less.

Further, as the flame retardant, a pulverized product of the above calcined product is used, and 25% by weight of an inorganic substance such as silica powder / an inorganic basic substance is added to 100 parts by weight of melam methanesulfonate of the present invention. The pulverized product added and adjusted below can be used ₍ the addition may be performed at room temperature to 400 ° C. That is, the addition may be performed before the completion of the above-described firing, or may be performed after the completion of the firing. It is preferable to use a mixing device having a shearing force, such as a Henschel mixer, a Lodige mixer, a homogenizer, a homomixer, etc., but a V-type mixer or a universal mixer After mixing, it may be applied to a pulverizer such as a pin disk mill, a jet atomizer, a ball mill, a counter jet mill, or an inomaizer. By pulverizing, fine powder having an average particle size of not more than 20 m, preferably not more than 10 m can be obtained, and after mixing at room temperature, at a temperature of 300 to 400 ° C. Here, the above-mentioned inorganic substance is a substance which is insoluble or has low solubility in water, for example, preferred examples include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and calcium silicate. , Magnesium silicate, calcium carbonate, silica powder, talc, zinc oxide, etc. Commercially available inorganic substances can be used.The calcined product of the present invention and the inorganic substance described above can be used. flame retardant containing the 0.0 1 solubility of 0. l O gZ l OO ml in water (2 5 ° C), and a 1 0 wt ^_0/0 aqueous slurry (2 5 ° C) 4 It can be set to a pH of 0 to 8.0.

Next, the flame-retardant polyamide resin composition of the present invention will be described. The flame-retardant polyamide resin composition of the present invention comprises the above-mentioned methanesulfonic acid melam in an amount of 1 to 100 parts by weight, preferably 3 to 80 parts by weight, based on 100 parts by weight of the polyamide resin. It is a compounded product. Further, based on 100 parts by weight of the polyamide resin, 1 to 100 parts by weight, preferably 3 to 80 parts by weight of the above methanesulfonic acid melan, and 1 to 300 parts by weight of the inorganic filler. Parts by weight. The amount of melam methanesulfonate is 1 If the amount is less than 10 parts by weight, the flame-retardant effect is not sufficient. If the amount is more than 100 parts by weight, the flame-retardant effect is not increased any more, and the moldability is rather lowered.

The flame-retardant polyamide composition of the present invention has a high degree of flame retardancy, and extremely hardly causes a dripping phenomenon in a UL-94 vertical combustion test. Further, there is almost no generation of decomposition gas or foaming during kneading, and contamination of the mold during molding is eliminated.

Examples of the polyamide resin used in the present invention include ε-force prolactam, aminocapronic acid, enanthactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 9-amido. Nononanoic acid, a-pyrrolidone, polymers such as monopiperidone, tetramethylene diamine, hexamethylene diamine, nonamethylene diamine, pendecamethylene diamine, Polymers obtained by polycondensation of diamines such as dodecamethylene diamine, methaxylylene diamine and dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanni basic acid and glutaric acid, or These copolymers, for example, polyamides, 4, 6, 7, 8, 11, 1, 12, 4, 6, 6, 6, 6, 9, 6, 10, 6, 11 and 6, 1 2 , 6Τ, 9T, MXD 6, etc. Two or more of these polyamide resins may be used in combination, and other thermoplastic resins such as polyolefin resins, polystyrene resins, ABS resins, AS resins, polycarbonate resins, polyphenylene ether resins, It may contain a modified polyphenylene ether resin, polyester resin, polyacetal resin, polysulfone resin, polyphenylene sulfide resin, polyimide resin, etc. As the inorganic filler used in the present invention, Known materials can be used, for example, glass fiber, carbon fiber, talc, my strength, silica, kaolin, clay, wollastonite, glass beads, glass flake, potassium titanate, and the like. Examples include calcium carbonate, magnesium sulfate, and titanium oxide. The shape of the agent may be any of fibrous, granular, plate-like, needle-like, spherical, powder, etc. In the flame-retardant polyamide resin composition of the present invention, as a flame retardant other than melam methansulfonate. Known flame retardants such as phosphorus-based flame retardants, inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, and silicone-based flame retardants, and nitrogen-based flame retardants can also be used in combination. Besides, heat stabilizer, light stabilizer, antioxidant, It can be used in combination with those usually used in the production of general synthetic resins such as antistatic agents, pigments, fillers, lubricants, plasticizers, and coupling agents.

In addition, the melane sulfonic acid melam of the present invention may be a resin other than a polyamide resin, for example, a thermosetting resin such as a phenol resin, an epoxy resin, a polyurethane resin, or an unsaturated polyester resin, or a polyolefin such as PE, PP, EVA, or EEA. Resin, PS, HIPS, AS, ABS, etc., polystyrene resin, vinyl chloride resin, polycarbonate resin, polyphenylene ether resin, modified polyphenylene ether resin, polyester resin, polyacetal resin, It is useful as a flame retardant for a wide range of resins such as thermoplastic resins such as polysulfone resin, polyphenylene sulfide resin and polyimide resin, and their copolymers and alloys. It is also useful as a flame retardant for these resin molded products, resin-containing paints and adhesives, fibers and textile products. Further, the melane methansulfonate of the present invention can be used not only as a flame retardant but also as a resin stabilizer.

The sample evaluation method in the present invention is as follows.

(1) Elemental analysis

(i) carbon, nitrogen, hydrogen and sulfur

The measurement was carried out using an elemental analyzer vario EL (manufactured by Elemental).

(2) High-speed liquid mouth chromatography

Melamine, melam, melem, etc., which are base components in the sample, were measured with a high-performance liquid chromatograph apparatus, Hitachi HI-400 (manufactured by Hitachi, Ltd.). The column used was a positive ion exchange resin-based column.

(Measurement condition)

Column PAT I S I L 10—SCX (250 mm X 4.6 mm), carrier mono-solvent 0.05 Μ ρ Η 3.7 phosphate buffer,

Carrier flow 1.0 ml / min,

Oven temperature 40 ° C,

Detection method UV detection method (230 nm) After dissolving the sample solution prepared sample 5 mg to Ol preparative-phosphate concentration S 5 weight ^_0/0 of ortho-phosphate solution 4 9 g, preparing a measurement sample solution was diluted to 5 0 0 ml with pure water I do.

(3) 1 0 wt ^_0/0 p H of the aqueous slurries (2 5 ° C)

After collecting 5 g of the sample in a 100 ml beaker, 45 g of pure water (25 ° C) was added. Next, a magnetic stirrer was put into the beaker and stirred with a magnetic stirrer for 10 minutes to prepare a 10% by weight aqueous slurry. Next, the above 10 weight. The / ₀ aqueous slurry was measured using a pH meter HM-26S (Toa Denpa Kogyo KK).

(4) Solubility in water (25 ° C)

In a 300 ml beaker, 5.00 g (ag) of the sample was precisely weighed, and 250 ml (25 ° C) of pure water measured by a measuring cylinder was added. Next, a magnetic stirrer was put into the beaker at a constant temperature (25 ° C), and the mixture was stirred for 3 hours with a magnetic stirrer to prepare a slurry. The adjusted slurry was suction-filtered with N 0.5 A filter paper which had been dried and refined in advance. At that time, after completion of the single filtration, the filtrate is collected in a separate container, and the undissolved sample used for filtration in the beaker where the slurry was prepared with the filtrate is attached to the N 0. Washed off on 5 A filter paper. Therefore, almost all of the undissolved sample was collected on N 0.5 A filter paper.

Next, N 0.5 A filter paper from which the undissolved sample was collected was placed in a Petri dish weighed precisely, and the Petri dish was placed in a hot air dryer preheated to 105 ° C and dried. . Then, the petri dish was immediately placed in a desiccator and allowed to cool.

After cooling, the total weight was measured, and the weight of the undissolved sample (b g) was obtained by subtracting the weight of the N 0.5 A filter paper and the dish from the total weight.

The solubility (g / 100 ml) was determined by the following formula: 100 · (a—Ι δ Ο).

(5) Average particle size

The 50% volume diameter (median diameter) was defined as the average particle diameter. The 50% volume diameter (median diameter) was measured with a laser diffraction type particle size analyzer PRO-70000S (manufactured by Seishin Enterprise Co., Ltd.). (Measurement conditions) Solvent: Isopropyl alcohol (25 ° C).

(6) Differential thermal analysis

The measurement was carried out using a differential thermal analyzer TGZDT A320 [manufactured by Seiko Electronics Co., Ltd.].

(Measurement conditions) Measurement temperature range: 20 to 550 ° C, heating rate: 10 ° CZ, air volume: 300m1 / min.

Example

Example 1

(a) Process

Melamine (manufactured by Nissan Chemical Industries, Ltd.) 31.0 kg (246.0 mol) was charged into a 130-liter Lödige mixer (stainless steel) equipped with a jacket, and the concentration was stirred. 7 0 weight ^_0/0 of meta Nsuruhon acid solution [Toyo Kasei Kogyo Co., Ltd.] 1 3. 5 kg of (meth Nsuruhon acid content 9 8.4 mol) was added and mixed for 20 minutes. After the addition was completed, warm water at 90 ° C was passed through the jacket, and stirring was maintained for 30 minutes while suctioning with a vacuum pump, to remove water by drying. Melamine was in a ratio of 2.5 mol to 1 mol of methanesulfonic acid. The obtained white powdery reaction product was 40.4 kg.

(b) Process

(a) 15 kg of the reaction product obtained in the step was put into a double-shaft type stirring type baking machine, and baked at 330 ° C. with stirring. The heating time was 34 ° C. in about 2 hours, and the firing temperature was kept at 340 ° C. for 6 hours. Sublimation of melamine by firing and generation of ammonia by condensation reaction of melamine were observed. 13.8 kg of a white powder was obtained as a fired product.

After cooling the fired product, it was pulverized by a pin disk mill. The average particle size of the obtained pulverized product was 4.

High-performance liquid chromatography of this calcined product showed melamin / melam melem = 0.8 / 93.3 / 5.9 (weight ratio).

The results of elemental analysis were as follows: carbon 25.96% by weight, nitrogen 48.74% by weight, 96 weight ^_0/0, sulfur 8.52 wt ⁰ /. Met.

Calculated from the results of elemental analysis of nitrogen and sulfur, and the weight ratio of the basic components melamine, melam, and melem in high-performance liquid chromatography, melamno sulfur atom = 1.1 1/1. 00 (molar ratio).

This calcined product had a pH of 5.1 as a 10% by weight aqueous slurry (25 ° C.). The solubility in water (25 ° C) showed a very small value of 0.04 gZl 00 ml.

FIG. 1 shows the result of differential thermal analysis (TGZDTA) of the fired product.

Example 2

(a) Process

Melamine [manufactured by Nissan Chemical Industries, Ltd.] 31.0 kg (246.0 mol) was charged into a 30-liter Lödige mixer (stainless steel) equipped with a jacket, and the concentration was 70% under stirring. weight ^_0/0 of meta Nsuruhon acid solution [manufactured by Toyo Kasei Kogyo Co., Ltd.] 1 6. LKG (the methane sulfonic acid content 1 1 7.4 mol) was added and mixed for 20 minutes. After the addition was completed, warm water at 90 ° C was passed through the jacket, and stirring was maintained for 30 minutes while suctioning with a vacuum pump to remove and dry water. Melamine was in a ratio of 2.1 mol to 1 mol of methanesulfonic acid. The obtained white powdery reaction product was 42.2 kg.

(b) Process

(a) 15 kg of the reaction product obtained in the step was placed in a double-shaft type stirring type baking machine, and baked at 330 under stirring. The heating time was 330 ° C in about 2 hours, and the firing temperature was maintained at 330 ° C for 5 hours. Sublimation of melamin by baking and generation of hammoyua by condensation reaction of melamin were observed. 13.9 kg of white powder was obtained as a fired product.

After cooling the fired product, it was pulverized by a pin disk mill. The average particle size of the obtained pulverized product was 5. O ^ m.

High-performance liquid chromatography of this calcined product showed that melamiram melem = 0.4 / 99.1 / 0.5 (weight ratio). The result of elemental analysis was as follows: carbon 25.07% by weight, nitrogen 47.16% by weight. / ₀ , hydrogen 4.02% by weight, sulfur 9.7 1 weight ⁰ /. Met.

Calculated from the results of elemental analysis of nitrogen and sulfur and the weight ratio of melamine, melam, and melem as base components in high performance liquid chromatography, melam / sulfur atom = 1.00 / 1.000 (Molar ratio).

This calcined product had a pH of 5.0 as a 10% by weight aqueous slurry (25 ° C). The solubility in water (25 ° C) was as low as 0.05 gZ100m1.

In the following Examples and Comparative Examples, an oxygen index and a 1-94 vertical combustion test were evaluated as a combustion test, and the foaming state of the extruded pellets was evaluated as follows.

(1) Oxygen index

The measurement was performed in accordance with JISK 7201.

(2) UL-94 vertical combustion test

It was measured by the UL-94 vertical burn test method specified by the United States Underwriters Laboratories. The thickness of the test piece was 1 to 8 inches.

(3) Foamed state of extruded pellet

The foamed state of the cut surface of the extruded pellet was visually observed and evaluated according to the following three grades. 〇: Almost no bubbles due to foaming:: Some bubbles due to foaming are observed, X: Bubbles due to foaming are remarkably seen

Examples 3, 4, 5

30% glass fiber reinforced nylon 66 (manufactured by Toray Industries, Inc .: trade name CΜ301-G30) shows the methane sulfonic acid melam (MMS-1) produced in Example 1 in Table 1. The mixture was mixed with a mixer at the ratio shown, and the mixture was kneaded using a twin-screw extruder (manufactured by Kurimoto Iron Works) at a cylinder temperature of 275 ° C and extruded into a strand. After cooling, it was cut and dried to obtain pellets. The obtained pellets were molded using an injection molding machine [manufactured by Nissei Plastic Industry Co., Ltd.] to obtain test pieces for a combustion test. Table 1 shows the evaluation results of these materials.

Examples 6, 7, 8 Examples 3, 4, and 5 except that methanesulfonic acid melam (MMS-2) produced in Example 2 was used instead of methanesulfonic acid melam (MMS-1) produced in Example 1. The same was done. Table 1 shows the evaluation results of these materials.

Comparative Example 1

Without using melam methanesulfonate, 30% glass fiber reinforced nylon 66 was directly injection molded to obtain a test piece for a combustion test. Table 1 shows the evaluation results.

Comparative Example 2

Melamine cyanurate (manufactured by Nissan Chemical Industries, Ltd .: MC-640) was used in place of methanesulfonic acid melam, and the other procedures were the same as in Example 6. Table 1 shows the evaluation results.

Comparative Example 3

Melam synthesized by the following method was used in place of melam methanesulfonate, and the other conditions were the same as in Example 4. Table 1 shows the evaluation results.

The melam was prepared as follows. A homogeneous mixed powder of 504 g of melamine and 380 g of paratoluenesulfonic acid monohydrate was fired in an electric furnace set at 290 ° C. for 6 hours. The calcined product had a dark brown color. The calcined product was washed with 3% aqueous ammonia to remove para-toluenesulfonic acid, and then filtered and dried to obtain 300 g of a melamine. As a result of high-performance liquid chromatography, the obtained melam was melamin / melam melem = 1.2 / 98.8 / 0.0 (weight ratio).

table 1

Example Comparative example

3 4 5 6 7 8 1 2 3 Nylon 66 100 100 100 100 100 100 100 100 100 100 Lath fiber 43 43 43 43 43 43 43 43 43

M S- 1 20 40 60 0 0 0 0 0 0

MS-2 0 0 0 20 40 60 0 0 0 C-640 0 0 0 0 0 0 0 60 0 Melam 0 0 0 0 0 0 0 0 40 Oxygen index 25. 0 30. 7 31. 1 25. 9 31 . 1 31. 1 22. 8 26. 8 26. 8

U L-9 4

Rank V-2 V-0 V-0 V-2 V-0 V-0 N / A N / A V- 2 Drift. Presence Yes Yes Yes Yes Yes Let foam state 〇〇 △ 〇〇 △ X △ Industrial applicability

Melam methanesulfonate obtained by the present invention is excellent in heat resistance and water resistance, and is extremely useful as a flame retardant especially for polyamide resins. Further, by using the melam methanesulfonate, it is possible to achieve flame retardancy of the synthetic resin without using a halogen-based flame retardant.

Claims

The scope of the claims

1. Water 0. 0. 1 to 0. 1 0 g Roh 1 0 0 ml solubility in (2 5 ° C), 3 to a 1 0-fold the amount ^_0/0 aqueous slurry (2 5 ° C). Methanesulfonic acid melamine having a pH of 0 to 7.0 and a ratio of melamine of from 0.90 to 1.30 per mol of sulfur atom.

2. Each of the following steps (a) and (b):

(a) Melamine and methanesulfonic acid are mixed at a temperature of 0 to 200 ° C at a ratio of 2.0 to 3.0 moles of melamin to 1 mole of methanesulfonic acid. Obtaining a reaction product by mixing at

Consisting of 0.0 1 to solubility of 0. l O g / l OO ml in water (2 5 ° C), and a 1 0 wt ^_0/0 aqueous slurry (2 5 ° C) 3. 0 A method for producing melamethane methansulfonate having a pH of 7.7.0 and a ratio of melam of 0.90 to 1.30 moles to 1 mole of sulfur atoms.

3. For 100 parts by weight of polyamide resin,

Water 0.0 1 to 0.1 with respect to (2 5 ° C) 0 g Bruno 1 0 0 ml of solubility, 1 0 wt ^_0/0 aqueous slurry (2 5 ° C) and to 3-0-7 1 to 100 parts by weight of methanesulfonic acid melam having a ratio of 0.90 to 1.30 mol of melam per 1 mol of pH and sulfur atom

A flame-retardant polyamide resin composition, which is blended with the above.

4. Further, with respect to 100 parts by weight of the polyamide resin,

1 to 300 parts by weight of inorganic filler

4. The flame-retardant polyamide resin composition according to claim 3, which is blended with a resin.