JPS6239174B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant polyester resin composition with good mechanical and electrical properties. Polyester has excellent mechanical properties, electrical properties, heat resistance, and moldability, so it has traditionally been used in a wide range of applications such as electrical parts, automobile parts, and precision machine parts, but it is relatively flammable. Due to the disadvantage that flame retardancy is required, its application is limited to electronic and electrical parts such as televisions and parts in the engine room of automobiles, which require flame retardancy. In order to make polyester flame retardant, many methods have been proposed for adding halogen compounds and phosphorus compounds as flame retardants, but although these flame retardants impart flame retardancy, they do not affect the excellent inherent properties of polyester. It is unsatisfactory in that it deteriorates mechanical properties, electrical properties, workability, etc. On the other hand, cyanuric acid,
Method of adding isocyanuric acid or derivatives thereof as a flame retardant (Japanese Unexamined Patent Publication No. 105744/1983)
have been proposed, but although these nitrogen-containing compounds can impart flame retardancy to polyamide by adding relatively small amounts, they do not have a sufficient flame retardant effect on polyester, and moreover, they do not cause decomposition of polyester during molding. There are problems such as causing Therefore, the present inventors conducted intensive studies with the aim of imparting excellent flame retardancy to polyester without impairing its original excellent mechanical properties, electrical properties, and heat resistance, and found that melamine and cyanuric acid were used as flame retardants. It was discovered that the above object could be achieved by using a salt consisting of (hereinafter abbreviated as melamine cyanurate) and, if necessary, a compound having a triazine ring skeleton as a dispersant, and the present invention was achieved based on this finding. That is, the present invention provides a flame retardant material in which a salt consisting of melamine and cyanuric acid is dispersed in a particle size of 10μ or less, which is made by blending 3020 parts by weight of melamine cyanurate and 03 to 10 parts by weight of a compound having a triazine ring skeleton with respect to polyester. The purpose of the present invention is to provide a polyester resin composition. According to the composition of the present invention, there is no decrease in electrical properties and arc resistance that often occurs when conventional halogen flame retardants are added, and there is no decrease in heat distortion temperature that occurs when phosphorus flame retardants are added. No decomposition, coloring, or gas generation during molding was observed when cyanuric acid was added as a flame retardant. For example, by adding 10 parts by weight of melamine cyanurate to 100 parts by weight of polybutylene terephthalate (hereinafter abbreviated as PBT), it is possible to meet V-2, which is a flame retardant material based on the UL-94 standard. ,
Moreover, it can be molded under exactly the same conditions as PBT without additives, and a molded product that retains the original properties of PBT can be obtained. The polyester to be made flame retardant in the present invention is polyethylene terephthalate (hereinafter abbreviated as PET).
PBT, polyethylene 2,6-naphthalate, polybutylene 2,6-naphthalate, polycyclohexylene dimethylene terephthalate, polycyclohexylene dimethylene phthalate/isophthalate copolymer, polybutylene terephthalate/isophthalate copolymer, etc. A mixture of these may be used. Further, a copolymer of the above polyester with brominated terephthalic acid or tetrabromobisphenol A/diethanol can also be used. In addition to the above polyester, other thermoplastic resins such as polyethylene, etc. may be added in an amount of 30% by weight or less.
Polypropylene, modified polyethylene, polystyrene, ABS resin, MBS resin, polycarbonate,
A polyblend containing polyamide or the like can also be applied to the present invention. Melamine cyanurate used as a flame retardant in the present invention means a salt formed from substantially equimolar amounts of melamine and cyanuric acid, such salts comprising a mixture of melamine and cyanuric acid, e.g. It is a powder obtained by thoroughly mixing the two salts to form fine particles, which are then filtered, dried, and pulverized, and is different from a simple mixture of melamine and cyanuric acid. This melamine/cyanurate does not necessarily have to be completely pure; it may contain some unreacted melamine or cyanuric acid, and may be produced by any industrially advantageous method. Available for use. However, it is preferable to use melamine cyanurate obtained in the form of a powder as fine as possible from the viewpoint of mechanical strength and aesthetic appearance of molded articles made from the present composition, and melamine cyanurate having a particle size of 100 μm or less is suitable. If the particle size of the melamine cyanurate is too large, the particles not only stand out on the surface of the molded product, degrading its aesthetic appearance, but also decreasing its mechanical strength, which is undesirable. The appropriate amount of melamine/cyanurate to be added is 3 to 20 parts by weight, preferably 5 to 15 parts by weight, per 100 parts by weight of polyester.If it is less than 3 parts by weight, the flame retardant effect will be small, and if it is more than 20 parts by weight, the polyester will This is not preferable because the mechanical properties of the material are greatly reduced. The composition of the present invention is prepared by supplying polyester and melamine/cyanurate to an extruder with or without premixing and melt-kneading them. It is desirable to uniformly disperse the particles with the following particle size. Such a dispersion state can be achieved by thoroughly kneading the melamine cyanurate with the molten polyester, provided the amount of melamine cyanurate is 20 parts by weight or less. , a twin-screw or triple-screw extruder, a kneader type kneader, etc. are preferably used. Although a better dispersion state is achieved when polyester is used in powder form rather than in chip form, it is also preferable to use a mixture of polyester chips and polyester powder. In order to achieve a better dispersion state, it is preferable to use a dispersant, and a compound having a triazine ring skeleton is suitable as the dispersant. The compound having a triazine ring skeleton herein refers to a derivative of cyanuric acid or isocyanuric acid, such as trisphenyl isocyanurate, trisbenzyl isocyanurate, tristryl isocyanurate, and lower tris(β-hydroxyethyl)isocyanurate. Examples include fatty acid esters and benzoic acid esters of tris (β-hydroxyethyl) isocyanurate, and the blending amount of these is approximately 0.3 parts by weight per 100 parts by weight of polyester.
~10 parts by weight is suitable. The composition of the present invention includes dyes, pigments, fillers, nucleating agents, mold release agents, heat resistant agents, weathering agents, plasticizers, flame retardants,
Other additives such as flame retardant aids, antistatic agents, fiber reinforcing agents, and hydrolysis inhibitors can be added in required amounts, especially fiber reinforcing agents such as glass fibers, asbestos fibers, and carbon fibers, epoxy resins, More desirable mechanical properties can be obtained when a hydrolysis inhibitor such as polycarbodiimide is blended or when melamine/cyanurate is previously treated with a surface treatment agent such as aminosilane or epoxysilane. In addition, the melamine cyanurate of the present invention can be used in combination with known halogen-based or phosphorus-based flame retardants, and in that case, the composition has significantly improved arc resistance compared to the case where only known flame retardants are added. can get things. The known halogen flame retardants mentioned here include decabrom diphenyl, decabrom diphenyl ether, tetrabromo phthalic anhydride, tetrabromo bisphenol A, and halogen-containing polycarbonate oligomers, and the phosphorus flame retardants include tri(nonyl phenyl) phosphorus. Examples include acid esters, triphenyl phosphate, diphenylphosphinate alkyl esters, bis(butylene glycol) diphenyl phosphinate, polybisphenol-S phenyl phosphate, etc., but the known ranges are particularly limited. It's not a thing. In addition to these known flame retardants, flame retardant aids such as antimony trioxide, stannic oxide, aluminum hydroxide, and zirconium oxide can of course be used. As explained above, the flame-retardant polyester resin composition of the present invention not only has excellent flame retardancy, but also maintains the good mechanical and electrical properties inherent in polyester, and is useful for expanding the uses of polyester. This will make a major contribution. The effects of the present invention will be explained in further detail with reference to Examples below. In addition, the number of parts in the examples indicates the number of parts by weight. Furthermore, the relative viscosity in the present invention is a value measured at 25° C. for a 0.5% orthochlorophenol solution of the polymer. Reference Example 1 An equimolar mixture of melamine and cyanuric acid was suspended in 10 times the weight of hot water, thoroughly stirred, and then the slurry was filtered to obtain a white cake. Next, this cake was vacuum dried at 70° C. and ground to obtain melamine cyanurate powder with a particle size of 1 to 5 μm. The melamine cyanurate powder thus obtained was added to 100 parts of dry PBT powder with a relative viscosity of 1.80 in the ratio shown in Table 1, and extruded at 250°C to form pellets. For comparison, instead of melamine cyanurate, cyanuric acid, melamine, tetrabromobisphenol A, and triphenyl phosphate were added to the PBT powder in the same manner and kneaded and extruded.
Using a screw-type injection molding machine, each pellet was made into 1/8″ tensile test piece, 1/2″ impact test piece, and 1/32″ impact test piece.
80mm × 1/16″, 1/8″ combustion specimen and 1/8″
An 80mm square plate was molded. The molding temperature was 250°C and the mold temperature was 80°C. Using these test pieces, various properties such as the physical properties shown in Table 1 were measured. In addition, various characteristics were measured according to the following measurements. Tensile test ASTM D638 Bending test ASTM D790 Izod impact ASTM D256 Heat distortion temperature ASTM D648 Combustion test U L 94 Arc resistance ASTM D495 These results are shown in Table 1, and it is clear that melamine cyanurate has excellent flame retardant effects. , and there is no deterioration in physical properties, and it is clear that it is effective in improving arc resistance.

【table】

[Table] Reference example 2 70 parts of PBT (relative viscosity 1.37), 30 parts of glass fiber (fiber length: 3 mm), 0.5 part of "Epicote 819", 0.2 part of talc, 20 parts of tetrabromo bisphenol A polycarbonate oligomer, antimony oxide Mix 6 parts and 10 parts of melamine cyanurate, 60mm
It was extruded at 270°C using a φ extruder and made into chips. For comparison, a similar experiment was conducted without adding melamine cyanurate. Furthermore, the same experiment was repeated using PET (relative viscosity 1.30). In that case, the molding temperature was 285°C. The chips obtained in these experiments were dried and injection molded into various test pieces using the method of Example 1, and their physical properties were measured. The results are shown in Table 2. As can be seen from the results in Table 2, the effect of melamine cyanurate on improving arc resistance is clear.

【table】

[Table] Example 1 10 parts of melamine cyanurate was added to 100 parts of PBT chips (relative viscosity 1.68), and the compounds shown in Table 3 were added as a dispersant, mixed, and kneaded into chips using a 30 mmφ extruder. did. However, in No. 15, 80 parts of PBT chips and 20 parts of PBT powder were used instead of 100 parts of PBT chips, and no dispersant was added. Each chip was formed into various test pieces by the method of Reference Example 1, and the physical properties, combustibility, and other characteristics were measured. In addition, thin sections were cut from the test pieces and the dispersion state of melamine/cyanurate was observed using an electron microscope. As a result, they were all uniformly dispersed to a size of 10 μm or less. The results are shown in Table 3.

【table】

Claims (1)

[Claims] 1 A salt consisting of melamine and cyanuric acid is prepared by blending 3 to 20 parts by weight of a salt consisting of melamine and cyanuric acid and 0.3 to 10 parts by weight of a compound having a triazine ring skeleton to 100 parts by weight of polyester.
A flame-retardant polyester resin composition dispersed with a particle size of 10μ or less.