JPS6138949B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION This invention relates to flame retardant compositions. Conventionally, synthetic resins (hereinafter referred to as plastics)
Due to its excellent physical properties and ease of molding, and in recent years, it has been used in a wide variety of applications, especially due to the demands for labor saving (improving productivity) and energy saving, and is used in home appliances, machinery, automobiles,
He has made great contributions to the development of architecture and other fields. However, in fields such as electronics such as televisions, electromechanical parts, automobile parts, and building materials, the demand for flame retardant plastic materials is becoming more and more severe year by year. Therefore, without sacrificing the original excellent properties of plastic, we have given it a high degree of flame retardancy that meets the material standards stipulated in the American Underwriters Laboratory's safety standard UL-1410 (for televisions). It became necessary to do so. Many methods have been proposed to make plastic flame retardant. For example, halogen-containing organic compounds, phosphorus-containing organic compounds, nitrogen-containing compounds, and various inorganic compounds are known to be effective as flame retardants. However, in order to meet the above flame retardant standards with these compounds, large amounts must be added, which not only impairs the excellent physical properties of plastics, but also requires uniform dispersion and kneading of a large amount of flame retardant. This is difficult and often results in poor operability. Relatively recently, elemental phosphorus, especially red phosphorus, has become known as an effective flame retardant in small amounts for some plastics, but it has only been put into practical use as a liquid raw material at around room temperature. kneading,
Only some curable resins can be molded. Red phosphorus has the risk of igniting and generating phosphine when subjected to high temperatures or mechanical shock, and therefore Japanese Patent Publication No. 54-39200 describes a method of coating the surface of red phosphorus particles with a thermosetting resin. However, its resistance to high temperatures and mechanical shock is insufficient, and its application to high melting point thermoplastic resins has not been realized. Also,
In thermoplastic resins with relatively low melting points such as polyolefins, polystyrene, ABS resins, AS resins, and polyvinyl compounds, relatively large amounts of red phosphorus must be added in order to meet flame retardant standards. The benefits of using phosphorus are not fully utilized and physical properties are likely to be impaired. The present inventors completed the present invention as a result of research to eliminate such defects. An object of the present invention is to provide a flame retardant composition that can be safely and easily applied to high melting point thermoplastic resins. Another object is to provide a flame retardant composition with increased flame retardant effect of red phosphorus. Such a purpose is to prepare a red resin impregnated with at least one thermoplastic resin selected from the group consisting of polyester, polyamide, polyurethane, polyester ether, and polyamide ether and a thermosetting resin having a pour point of 50 to 210°C. This is achieved by a flame retardant composition consisting of phosphorus powder and containing 30 to 70% by weight of elemental red phosphorus. In the present invention, the pour point of the thermoplastic resin substantially coincides with the melting point in the case of a crystalline resin, and means the temperature at which the dynamic elastic modulus is 10 ⁸ dyne/cm ² or less. The film-like sample was measured using "Rheovibron" manufactured by Toyo Baldwin. Polyesters used in the present invention include homopolyesters such as polyhexylene terephthalate, polyethylene isophthalate, polybutylene isophthalate, polyester sebacate, and poly-ε-caprolactone, as well as various aromatic or aliphatic dibasic acids, Examples include copolyesters obtained by combining oxyacids and diols. Raw material monomers other than the homopolyester constituent monomers mentioned above include P-hydroxyethoxybenzoic acid, orthophthalic acid, P,P'-biphenyldicarboxylic acid, naphthalene-2,6-dicarboxylic acid,
Oxybenzoic acid, tetrabromterephthalic acid,
Tetrabromophthalic acid, tetrachlorophthalic acid, oxalic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, propylene glycol, phthanediol, neopentyl glycol, 1,4-
Cyclohexane methanol, octanediol,
Bis-β-hydroxyethoxybenzene, bis-
P-xyphenylsulfone, 2,2'-bis-P-
Oxyphenylpropane, bis-P-(β-hydroxyethoxyphenyl)sulfone, 2,2′-bis-P-(β-hydroxyethoxyphenyl)propane, bis-P-oxytetrabromophenylsulfone, 2 In addition to bifunctional compounds such as , 2'-bis-P-oxytetrabromophenylpropane, polyfunctional compounds such as pentaerythryl, pyromellitic acid, trimellitic acid, etc. can also be used in part. An example of a preferred copolyester is polyethylene terephthalate/isophthalate. Of course, mixtures of various polymers can also be used. Examples of the polyamide used in the present invention include aliphatic polyamides such as so-called nylon 9, 11 nylon, 12 nylon, and 6,9 nylon, and aromatic polyamides such as polyhexamethylene isophthalamide and polymethaxylylene isophthalamide. . In addition to these homopolymers, various copolymerized polyamides can also be used, and in addition to the constituent monomers of each of the polyamides mentioned above, lactams such as pyrrolidone and ε-caprolactam, ethylenediamine, tetramethylenediamine, octamethylenediamine, nona Diamines such as methylene diamine, decamethylene diamine, untecamethylene diamine, dodecamethylene diamine, bis-γ-aminopropyl ether, para-xylylene diamine, ortho-xylylene diamine, piperazine, and raw materials for the polyesters mentioned above. Examples include those obtained by combining various dicarboxylic acids. It is also possible to use mixtures of various polymers. Examples of preferred polyamides include copolymers of polyhexamethylene isophthalamide and various diamine salts of terephthalic acid or isophthalic acid as ε-caprolactam. The polyurethane used in the present invention is obtained by polymerizing a prepolymer obtained by reacting various high molecular weight polyols with aliphatic and/or aromatic diisocyanates using various chain extenders. Typical examples include polyethylene adipate, polybutylene adipate,
Examples of diisocyanates include poly-ε-caprolactone, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., and 4,4'-diphenylmethane diisocyanate, toluylene diisocyanate, hexamethylene diisocyanate, etc. , as a chain extender, ethylene glycol, 1,4-butanediol, bis-β-hydroxyethoxybenzene, N-methyldiethanolamine, N,N'-dimethylhexamethyleneamine, hexamethylenediamine, ethylenediamine, N,N'- Examples include diethylethylenediamine m- or p-xylylenediamine. The polyester ether or polyamide ether used in the present invention includes the above-mentioned raw material monomers (or oligomers) of polyester or polyamide, and polyethylene glycol, polypropylene glycol, polybutylene glycol of various degrees of polymerization, or these. Examples include random or block copolymers obtained by using polyether diamine in which the terminal hydroxyl group is changed to an amino group. The hydroxyl group of the polyol can be converted into an amino group by hydrogenating the nitrile group after an acrylonitrile addition reaction (dianoethylation). As the polyethylene glycol, polyethylene glycols having a molecular weight of several hundred to tens of thousands can be used, ranging from low molecular weight ones such as diethylene glycol and triethylene glycol. The same applies to other polyols. The thermoplastic resin used in the present invention includes mixtures of the above-mentioned polymers, but polyamides and polyesters are particularly preferred. Also included are copolymers other than those mentioned above, such as polyester amide and polyester amide ether, which are obtained by reacting raw material monomers, oligomers, or polymers of each polymer. Examples of polyesteramides include:
Examples include those obtained by reacting ethanolamine with dicarboxylic acids such as sebacic acid. The thermoplastic resin used in the present invention is for the matrix of the red phosphorus master chip, so to speak.
When blended into a high molecular weight resin, the molecular weight must be large enough not only to not impair the physical properties of the resin, but also to withstand mechanical and thermal shock when kneaded as a flame retardant. Usually average 5000~
300,000, preferably a range of 7,000 to 150,000 is used. In the present invention, red phosphorus is impregnated and cured with a thermosetting resin to improve heat resistance and impact resistance. This is because the thermal stability and impact resistance of a certain thermosetting resin decrease significantly from around this temperature or higher, and preferably at a temperature of 200°C or higher.
By keeping the temperature below °C, it becomes possible to blend red phosphorus at a high concentration. In addition, in order to obtain a resin composition containing a high concentration of red phosphorus in the form of easy-to-handle chips or flakes at room temperature, the thermoplastic resin must have a pour point of 50°C or higher, preferably 80°C or higher. It is better. This is because when the high-concentration red phosphorus composition of the present invention is melt-kneaded with a thermoplastic resin having a high melting point to make the resin flame retardant, if the pour point is too low, smooth kneading is often not possible. is also a necessary condition. The polyester, polyamide, polyurethane, polyester ether, polyamide ether used in the present invention improves the flame retardant effect of red phosphorus when they exist surrounding red phosphorus, and has a preferable pour point and viscosity. It has the advantages of being easy to obtain, having flexible physical properties, and significantly softening the mechanical impact on red phosphorus. The red phosphorus impregnated and cured (coated) with a thermosetting resin used in the present invention usually has an average particle size of approximately
0.1-100 microns (μ), preferably 0.5-30μ
Red phosphorus is coated with a resin selected from the group consisting of phenol resin, melamine resin, urea resin, furfuryl alcohol resin, aniline resin, ketone resin, epoxy resin, and unsaturated polyester resin, and the amount of coating is usually 1 to 30% by weight relative to red phosphorus. Generally, a coating of 5 to 20% by weight provides stabilized red phosphorus with less agglomeration between particles, and exhibits significant oxidation and impact suppression effects in air. The most preferred resins include phenol/aldehyde resins, urea, aldehyde resins, and melamine/aldehyde resins. Treatment with thermosetting resin is usually performed by adding resin raw materials (including initial condensate) to a red phosphorus aqueous suspension, stirring vigorously,
The treatment may be carried out under the usual polymerization conditions for each resin. Either red phosphorus is treated in advance with metal salts such as copper, nickel, silver, or iron, or red phosphorus is treated with copper oxide, antimony oxide, lead oxide, molybdenum sulfide, molybdenum oxide, zinc oxide, zinc borate, manganese oxide, etc.
cobalt oxide, magnesium hydroxide, activated carbon,
Stabilizers such as melamine, cyanuric acid, melamine cyanurate, polyacrylonitrile powder, phosphine absorbers, flame retardant enhancers, or other halogenated organic compounds such as brominated diphenyl ethers, tribromonophenol oligomers, etc. It is also possible to mix and process flame retardant powder. Antimony oxide is most preferred as the phosphine absorbent, and in that case it is added in an amount of 0.01 to 2 times the amount of red phosphorus. The blending amount of the thermosetting resin coating red phosphorus in the present invention is 30 to 70% by weight, preferably 35 to 60% by weight as elemental red phosphorus, based on the total amount of the composition. If it exceeds 70% by weight, it will not lead to a further significant improvement in the handling safety of red phosphorus already coated with thermosetting resin, but rather it will increase the risk of mechanical shock during manufacturing (kneading), so it must be avoided. Must be. In addition, if it is less than 30% by weight, the red phosphorus content is insufficient for a master chip, and as a result of blending a large amount of low pour point resin with red phosphorus into a high melting point thermoplastic resin, it has disadvantages such as deterioration of physical properties. . In general, the amount of red phosphorus added can be increased at lower temperatures.
At temperatures above 200°C, it is quite difficult to mix 40% by weight or more unless the resin is pulverized in advance, but below 200°C, it is easy to mix 40% or more by weight. In the present invention, the thermosetting resin coating red phosphorus is incorporated into the thermoplastic resin by thoroughly dispersing the former into the latter in a melt kneader. In order to soften the mechanical impact on red phosphorus, part or all of the resin may be used in powder form. In addition, relatively soft and slippery inorganic fine powders such as talc and clay can also be used together.
Further, at this time, powders such as the above-mentioned red phosphorus stabilizer, phosphine absorbent, other flame retardants, and pigments can also be used in combination. Preferred phosphine absorbers and flame retardants include antimony oxide, melamine, decaprom diphenyl ether, and the like. The amount of these powders used together varies depending on the properties of each powder and the purpose of use, but it is usually 0.01 to 2 times the weight of red phosphorus, preferably 0.05 to 1 times the weight of red phosphorus. The flame retardant composition containing a high concentration of coated red phosphorus obtained in the present invention is used by blending with various thermoplastic resins. In that case, by taking compatibility into consideration and selecting kneading conditions, it is possible to blend polyolefin, polystyrene, AS resin, ABS resin, etc., and the flame retardant effect is better than when red phosphorus is directly blended with these resins. will be excellent. Directly kneading red phosphorus into well-known high melting point or high pour point thermoplastic resins such as polyethylene terephthalate, nylon 66, polycarbonate, modified polyphenylene oxide, etc. will cause red phosphorus to ignite, decompose, and cause toxic gas. It was difficult to put it to practical use even in the case of red phosphorus coated with a thermosetting resin because it is likely to generate a large amount of certain phosphine. However, by using the composition of the present invention, it can be safely and thermosetted. It can be made flame retardant without damaging the protective film of the polyester resin. Of course, it can also be effectively used for thermoplastic resins with lower melting points. Compounding can be carried out using a continuous or discontinuous kneading machine or various molding machines, and at this time, modifications such as various fillers, pigments, stabilizers, other flame retardants, reinforcing agents, lubricants, etc. are added as necessary. Materials can be mixed as appropriate. The present invention will be specifically explained below with reference to Examples, but of course it is not limited thereto. The pour point of the thermoplastic resin of the present invention is the temperature at which the dynamic elastic modulus is 10 ⁸ dyne/cm ² or less, but for a film sample of 40 mm x 5 mm x 0.2 mm, It was measured at a frequency of 11 cycles using ``RheoVibrone''. In crystalline polymers, the so-called
It almost matches the melting point (crystal melting point) measured using a DSC (Differential Scanning Colorimeter). In addition, "part" indicating the unit of amount used in the examples,
Alternatively, "%" is by weight unless otherwise specified. Furthermore, the relative viscosity, which is a measure of the degree of polymerization (molecular weight) of a polymer, was measured at a concentration of 1% in dimethylformamide for polyurethane, and in a mixed solvent of phenol and dichloroethane for other polymers. In addition, the tensile strength of the molded product is ASTM D-638, impact strength (notched)
The flame retardance was measured according to the American Underwriters Laboratory's standard UL-94. Example 1 Terephthalic acid (TPA) component 70 to 100 mol%,
The pour point (FP) of polyethylene terephthalate (PET) having a relative viscosity of 2.0±0.1 and containing 30 to 0 mol% of isophthalic acid (IPA) was 175 to 260°C. These polyester and phenolic resin coated red phosphorus powder (phenolic resin
14%, red phosphorus 86%, Rin Kagaku Kogyo's "No Ballet"
120'') under the ratio and temperature conditions shown in Table 1.
The mixture was melt-kneaded using a continuous shaft kneader to obtain red phosphorus-containing chips. The kneading operation was carried out while flowing nitrogen gas through the raw material supply port, and was smooth, but the kneading temperature
At temperatures above 230°C, there was a strong phosphine odor both at the extrusion outlet (die) and in the chips obtained. When the kneading temperature was 230°C or higher, the amount of red phosphorus blended was reduced and a portion of the polyester was pulverized to avoid mechanical shock, but the decomposition of red phosphorus could not be suppressed completely. The obtained chip with a high red phosphorus concentration (master chip) was mixed with polyethylene terephthalate having a relative viscosity of 1.85, and a mechanical property test piece and a flame retardant test piece were prepared using an injection molding machine. however
The products kneaded at 250°C and 270°C with a red phosphorus concentration of 3% (in terms of elemental red phosphorus) were used as they were, and as a reference example, polyethylene terephthalate with a relative viscosity of 1.90 was injection molded as is. The molding machine cylinder temperature was 265 to 270°C, the mold temperature was 130°C, and the red phosphorus concentration was constant at 3% except for the reference example. Although the molding operation was smooth, in the comparative example in which the kneading temperature had to be increased during master chip production, there was a strong phosphine odor in the chip supply port, injection nozzle, mold, and in the molded product.
It was difficult to perform molding intermittently. This is thought to be due to the red phosphorus phenol resin coating being severely damaged during master chip manufacturing. The physical properties and flame retardance of each test piece obtained are shown in Table 1, and it appears that the master chip obtained by melting and kneading high-concentration red phosphorus at a lower temperature maintains better physical properties. .

[Table] Example 2 The pour point of polyhexamethylene isophthalamide, which was produced from hexamethylene diamine and isophthalic acid and had a relative viscosity of 2.2, was 167°C. 100 parts of this polyamide and 116 parts of the same phenolic resin coated red phosphorus powder used in Example 1 were added to 2
Melt mixing was carried out using a continuous shaft kneader at a cylinder temperature of 175°C. The kneading operation was smooth and there was almost no phosphine odor at the extrusion port or in the chips obtained. 15 parts of the obtained master chips were mixed with a relative viscosity of 2.2
100 parts of polyhexamethylene adipamide (6.6 nylon) chips with a relative viscosity of 2.5
ε-Caprolactam (Nylon 6) Chip 100
A mechanical property test piece and a flame retardant test piece were prepared using an injection molding machine. Molding machine cylinder temperature is 265℃ for nylon 66, 235℃ for nylon 6,
Although the mold temperature was 65°C, the molding operation was smooth and there was almost no phosphine odor. For comparison, the above nylon 66 and nylon 6 were pulverized by freeze-pulverization, 100 parts of each were mixed with 8 parts of the phenolic resin coated red phosphorus powder, and the mixture was melt-kneaded at 270°C and 240°C, respectively. Injection molding was carried out under the same temperature conditions as in each Example, but significant phosphine generation occurred during both melt-kneading and injection molding, making intermittent work impossible. The physical properties and flame retardance of the injection molded product are shown in Table 2 along with the cases of molded 66 nylon and 6 nylon alone for reference, and excellent flame retardance was obtained.
It can be seen that the physical properties deteriorated only slightly compared to the reference example.

【table】

[Table] Example 3 Polytetramethylene glycol 69 with a molecular weight of 1000
and 4,4'-diphenylmethane diisocyanate
25 parts, a polyurethane resin with a relative viscosity of 1.8 obtained by polymerizing 6 parts of chain extender bis-β-hydroxyethoxybenzene, a commercially available polyester ether resin "Pemplene P150M" (manufactured by Toyobo Co., Ltd.),
and 100 parts each of commercially available polyamide ether resin "Diamid-PAX-X-4138" (manufactured by Daicel Hyurus Co., Ltd.), 174 parts of phenolic resin coated red phosphorus "Nobaled 120" and 20 parts of antimony oxide powder were mixed, and a biaxial The mixture was melt-mixed using a continuous kneader under the temperature conditions shown in Table 3. The kneading operation was smooth, and there was no phosphine odor at the extrusion port or in the chips obtained. 20 parts of each master chip obtained was mixed with 100 parts of the same polystyrene chip having a relative viscosity of 25, and mechanical property test pieces and flame retardant test pieces were prepared using an injection molding machine. Although the molding machine cylinder temperature was 180°C and the mold temperature was 40°C, each molding operation was smooth and there was no phosphine odor at all. For comparison, 12 parts of the phenolic resin coated red phosphorus powder and 1.3 parts of antimony oxide powder were mixed with the above polystyrene, melt-kneaded at 190°C, and injection molded under almost the same conditions as in the above example. There was no phosphine odor. However, as shown in Table 3, there were differences in the flame retardancy of the injection molded products, which remained at V-2 of the UL-94 standard. For reference, we have shown the strength and flame retardance of a test piece obtained by injection molding the above polystyrene.
Each of the examples had slightly inferior tensile strength, but excellent impact strength.

【table】

Claims (1)

[Claims] 1. Impregnating and curing a thermosetting resin with at least one thermoplastic resin selected from the group consisting of polyester, polyamide, polyurethane, polyester ether, and polyamide ether having a pour point of 50 to 210°C. A flame retardant composition comprising 30 to 70% by weight of elemental red phosphorus. 2. The composition according to claim 1, which has a pour point of 80 to 200°C. 3. The composition according to claim 1, wherein the thermoplastic resin is polyester or polyamide. 4. The composition according to claim 1, wherein the polyester is polyethylene terephthalate/isophthalate. 5. The composition according to claim 1, wherein the polyamide is a copolymer of polyhexamethylene isophthamide or ε-caprolactam and terephthalic acid or a diamine salt of isophthalic acid. 6. The composition according to claim 1, wherein the thermosetting resin is phenol, aldehyde resin, urea, aldehyde resin, or melamine/aldehyde resin. 7. The composition according to claim 1, wherein the red phosphorus powder impregnated and cured with a thermosetting resin has an average particle size of 0.1 to 100 μ. 8. The composition according to claim 1, wherein the content of elemental red phosphorus is 35 to 60% by weight.