JPS6215095B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel flame-retardant resin composition, and more particularly to a flame-retardant resin composition comprising a polycarbonate resin and a polyphosphate metal salt. polycarbonate resin, polyolefin resin,
Thermoplastic resins such as polystyrene, ABS resin, polyester, polyamide, acrylic resin, and polyvinyl chloride resin have various advantages such as good moldability, good durability, light weight, and low cost. Therefore, it is applied in various fields,
On the other hand, since it has the disadvantage of being easily flammable, its fields of use are partially restricted from the viewpoint of safety. Conventionally, in order to make thermoplastic resins flame retardant, flame retardants such as organic halides and phosphate esters have been added to thermoplastic resins, and metal oxides such as antimony trioxide have been added to these flame retardants. It is used as a combustion aid. Incidentally, in recent years, flame retardant standards such as the UL standard regarding the safety of thermoplastic resins have been strengthened year by year, so there is a strong demand for highly flame-retardant thermoplastic resins. Generally, thermoplastic resins can be made highly flame retardant by adding a large amount of flame retardant. However, in this case, the addition of a large amount of flame retardant causes damage to the resin itself. In addition to damaging the physical properties of the flame retardant, thermal decomposition of the flame retardant during melt molding causes various problems such as discoloration of the resin, corrosion of machinery due to the generation of toxic corrosive gases, and deterioration of the working environment. Furthermore, there are other problems such as reduced weather resistance of the obtained molded articles, generation of toxic gas during combustion, and toxicity of the flame retardant itself. The inventors of the present invention have conducted intensive research to overcome the above-mentioned drawbacks in conventional flame retardant thermoplastic resins, and have unexpectedly found that by blending polyphosphate metal salts as flame retardants into polycarbonate resins, the objective has been achieved. The inventors have discovered that the following can be achieved, and have completed the present invention. In the present invention, the flame retardant applied to the polycarbonate resin is an alkali metal salt of polyphosphate. In this case, the alkali metal polyphosphate includes various condensed metal phosphates such as alkali metal pyrophosphate, alkali metal triphosphate, alkali metal trimetaphosphate, and alkali metal tetrametaphosphate, and the following general It can be expressed by the formula. (M)PnO ₃ n+ ₁ , (M)(PO ₃ )n () () (where M represents an alkali metal such as Na or K,
n represents an integer of 2 or more. )Na, K, Ca,
Examples include Mg, Mn, and Ni. The blending ratio of this alkali metal polyphosphate is 0.1 to 40 parts by weight, preferably 0.1 to 40 parts by weight per 100 parts by weight of the polycarbonate resin.
The proportion is 0.5 to 20 parts by weight. In addition, here, the polycarbonate resin is produced by the reaction of divalent phenol and phosgene or carbonic acid diester. As the divalent phenol compound, bisphenols are preferred, and 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) is particularly preferred. Further, part or all of bisphenol A may be replaced with another divalent phenol compound.
Examples of divalent phenol compounds other than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, and bis(4-hydroxyphenyl).
Alkanes, bis(4-hydroxyphenyl)cycloalkanes, bis(4-hydroxyphenyl)oxide, bis(4-hydroxyphenyl)sulfide, bis(4'-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfoxide, (enyl) sulfone, bis(4-hydroxyphenyl) ketone, or halogen-substituted products thereof.
Homopolymers of these dihydric phenols or
It may be a copolymer of more than one species or a blend thereof. The flame retardant resin composition of the present invention may optionally contain an organic halogen compound or at least one substituent selected from a hydroxyl group, a mercapto group, an amino group, and a formyl group as a flame retardant. At least one flame retardant compound selected from nuclear-substituted benzoic acids can be blended. Organic halogen compounds used as flame retardant aids are
Aromatic compounds, alicyclic compounds, aliphatic compounds, etc. that contain halogen atoms such as bromine, chlorine, and fluorine in their molecular structures, which further enhance the flame retardant effect of the alkali metal polyphosphate as a flame retardant. It includes all organic halogen compounds that have a flame retardant effect. Specifically, hexabromobenzene: pentabromotoluene: biphenyl bromide: triphenyl chloride: diphenyl bromide ether: tetrachlorophthalic acid; tetrabromo phthalic anhydride; tribromophenol; tribromophenyl; dibromoalkyl diphenyl ether ; Tetrabromobisphenol S; Tetrachlorobisphenol A; 2,2-bis(4-hydroxy-
In addition to 3,5-dibromophenyl)-propane (hereinafter referred to as "tetrabromobisphenol A"), tetrabromobisphenol sulfone, tetrabromobisphenol ether, aromatic halogen compounds represented by the following formula: can be mentioned. Still other specific examples of organic halogen compounds that can be used as flame retardants include monochloropentabromocyclohexane; hexabromocyclododecane;
Perchloropentacyclodecane; alicyclic halogen compounds such as hexachloroendomethylenetetrahydrophthalic anhydride, and further chlorinated paraffin; chlorinated polyethylene; tetrabromoethane;
Tetrabromobutane; Tris(β-chloroethyl)phosphate; Tris(dichloropropyl)
Examples include aliphatic halogen compounds such as phosphate; tris(dibromopropyl) phosphate; tris(chlorobromopropyl) phosphate. The blending ratio of these organic halogen compounds varies depending on the type and cannot be unambiguously determined, but in general, it is 0.1 to 40 parts by weight, based on 100 parts by weight of polycarbonate resin.
Preferably it is 0.5 to 20 parts by weight. Further, nuclear-substituted benzoic acid used as a flame retardant in addition to the organic halogen compound is represented by the following general formula. In the formula, X is a hydroxyl group (-OH), a mercapto group (-SH), an amino group ( _-NH2 ), or a formyl group (-CHO), and n is an integer of 1 to 5. In a nuclear-substituted benzoic acid in which two or more substituents X are bonded to a benzene nucleus, the two or more substituents X may be the same or different substituents. Specific examples of such nuclear-substituted benzoic acids include salicylic acid, thiosalthioic acid, dihydroxybenzoic acid, aminobenzoic acid, aminosalicylic acid,
Examples include O-formylbenzoic acid. The blending ratio of such nuclear-substituted benzoic acid is generally 0.1 to 15 parts by weight per 100 parts by weight of polycarbonate resin.
The proportion is 0.5 to 5 parts by weight, preferably 0.5 to 5 parts by weight. In the present invention, it is possible to obtain a polycarbonate resin composition that is more highly flame retardant by blending the above-described organic halogen compound or further nuclear-substituted benzoic acid as a flame retardant together with an alkali metal polyphosphate as a flame retardant. can. Furthermore, the present invention does not preclude the incorporation of appropriate amounts of other conventionally known flame retardants or flame retardant aids.
Furthermore, as auxiliary ingredients, customary additives such as reinforcing agents, fillers, heat stabilizers, UV absorbers,
Plasticizers, colorants, etc. can be added. The type and amount of such auxiliary additives are appropriately selected depending on the type of polycarbonate resin and its intended use. The flame-retardant resin composition of the present invention exhibits a high degree of flame retardancy due to the strong flame-retardant action of the alkali metal polyphosphate used as a flame retardant, and the alkali metal salt polyphosphate in this case is thermally stable. Because it has extremely high properties, it does not undergo thermal decomposition during melt molding, unlike conventional formulations containing large amounts of flame retardants, and does not discolor the resin or worsen the working environment. Furthermore, in the present invention, when organic halogen compounds, nuclear-substituted benzoic acids, or other commonly used flame retardants are used together as flame retardants, the amount of these added can be significantly smaller than in the conventional case. No particularly difficult problems arise due to the formulation. Due to its excellent flame retardancy, the flame retardant resin composition of the present invention can
It is advantageously used in various fields such as machinery, office equipment, automobiles, and building materials. Next, the present invention will be explained in more detail with reference to Examples. Example 1 Polycarbonate resin powder (average molecular weight
Using 100 parts by weight of 25000), flame retardant A (polyphosphate), flame retardant B (organohalogen compound) and flame retardant C (nuclear substituted benzoic acid) shown in Table 1 were blended with it, and Labo Plastomil was prepared. 10 at 230-250℃ using
After melt-kneading for minutes, compression molding (230-250℃)
It was molded into a sheet with a thickness of 3 mm. A test piece of 3 mm x 6.5 mm x 127 mm was prepared from this sheet, and the oxygen index (OI) of this test piece was measured according to JISK-7012. The results are shown in Table 1. In addition, each code shown in the table means the following. TBS…Tetrabromobisphenolsulfone bromo compound… TSA...thiosalicylic acid DHBA...dihydroxybenzoic acid Oxygen index (OI) is defined as the minimum percentage of O ₂ in the O ₂ /N ₂ mixture required to continuously burn a sample, and the higher the value, the higher the oxygen index (OI). Meaning it is more flame retardant.

[Table] As is clear from the results shown in the table above, compositions No. 1 to 1 containing polyphosphate metal salts according to the present invention
No. 4 exhibited better flame retardancy than Compositions No. 11 to 13 containing organic halogen compounds conventionally used as flame retardants, and also used polyphosphate metal salts in combination with organic halogen compounds and nuclear-substituted benzoic acids. composition
It can be seen that compositions Nos. 5 to 8 exhibit higher flame retardancy than compositions Nos. 1 to 4 in which polyphosphate metal salt was used alone. Moreover, in the case of the present invention, it can be seen that a large flame retardant effect can be obtained by adding a small amount of flame retardant. Example 2 Polycarbonate powder consisting of bisphenol A as thermoplastic resin (average molecular weight 25000)
Using 100 parts by weight, the flame retardants shown in Table 2 were added thereto, and the mixture was pelletized by melt-kneading extrusion at a temperature of 265 to 300°C using a 50 mmφ extruder. After drying the pellets at 120℃ for 6 hours, injection molding was performed.
A test piece of 12.7mm x 3.2mm was prepared and a vertical flammability test was conducted according to the UL-94 standard. The results are shown in Table 2.

【table】

Claims (1)

[Claims] 1. A flame-retardant resin composition comprising a polycarbonate resin and an alkali metal salt of polyphosphate. 2. The composition according to claim 1, wherein the amount of the alkali metal polyphosphate is 0.1 to 20 parts by weight based on 100 parts by weight of the polycarbonate resin. 3. The composition according to claim 1 or 2, which comprises an organic halogen compound and an alkali metal polyphosphate. 4 Claim 1 comprising a polyphosphoric acid alkali metal salt, an organic halogen compound, and a nuclear-substituted benzoic acid having at least one substituent selected from a hydroxyl group, a mercapto group, an amino group, and a formyl group. ~The composition according to any one of Item 3.