JPH0255456B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention relates to a flame-retardant polyester resin composition, and more particularly to a resin composition composed of two or more types of thermoplastic polyesters that has excellent flame retardancy and moldability and retains its physical properties. <Prior art> Thermoplastic polyester resins, especially polyalkylene terephthalate resins, have high heat resistance and excellent physical properties such as mechanical properties, electrical properties, and chemical resistance, and are used in electrical/electronic parts, automobile parts, and mechanical parts. It is widely used. Furthermore, in order to further increase heat resistance and rigidity, studies have been made to incorporate other types of additives such as glass fiber and fillers to improve the insufficient properties. Furthermore, efforts have been made to blend other types of polyesters with these polyesters in an attempt to further improve their functionality. For example, techniques are known in which polyester elastomer is added to polybutylene terephthalate to improve impact strength, and polyethylene terephthalate is added to polybutylene terephthalate to improve appearance gloss. Such mixtures of two or more polyesters have the disadvantage of being relatively flammable. It is widely used to add organic halogen compounds to impart flame retardancy, but organic halogen compounds alone do not have a sufficient flame retardant effect, so flame retardant aids such as antimony trianide are used in combination. method is adopted. However, although it is relatively easy to impart flame retardancy to a mixture of two or more polyesters using this method, these additives tend to cause transesterification reactions between polyesters during melt heating, and This method has the disadvantage of causing a decrease in thermal stability and further a decrease in the strength of the obtained molded product. <Object of the Invention> The object of the present invention is to provide a polyester resin composition that has good flame retardancy and moldability, and retains the resulting molded product and the physical properties inherent to polyester. <Structure of the Invention> The present invention is a composition comprising at least two types of thermoplastic polyester (A), an organic halogen compound (B), and an antimony compound (C), wherein the antimony compound (C) is the following (1). ) is a compound with the chemical structure shown in
This is a flame-retardant polyester resin composition that has been heat-treated at a temperature of 100°C or higher. _XNa2O・_Sb2O5・_YH2O ...(1) (However, in the formula, X is 0.1 _to 0.8, and Y is the number of crystallized water, which is 0.25 to 4.0.) Both types of thermoplastic polyesters (A) are selected from two or more types of polymers that can be obtained by polycondensation of aromatic dicarboxylic acids and/or aromatic oxycarboxylic acids and diols as acid components. Representative examples of the aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, and diphenyldicarboxylic acid, and representative examples of the aromatic oxycarboxylic acids include oxybenzoic acid and hydroxyethoxybenzoic acid. be done. Only one type of these may be used, or two or more types may be used in combination. Further, typical diols include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, polyethylene glycol, and polytetramethylene glycol. These are 1
It may be one type alone or a combination of two or more types. Typical combinations of two types of such polyesters include, for example, polyethylene terephthalate/polybutylene terephthalate, polyethylene terephthalate/(polyester elastomer obtained from terephthalic acid, tetramethylene glycol, polytetramethylene glycol),
Polybutylene terephthalate/(terephthalic acid,
Examples include polyester elastomers obtained from tetramethylene glycol and polytitramethylene glycol. The mixing ratio of these two or more types of polyesters is not particularly limited, and they can be mixed in any ratio. The organic halogen compound as component (B) used in the present invention refers to a compound that is generally treated as a halogen flame retardant, but considering the heat history it undergoes during the molding process of the polyester resin composition, it has excellent heat resistance. Aromatic halogen compounds are preferred. For example, decabromodiphenyl ether,
Halogenated polycarbonates such as brominated polycarbonate obtained from tetrabromobisphenol A and phosgene, brominated copolycarbonate obtained from tetrabromobisphenol A and bisphenol A and phosgene, bromine obtained from tetrabromobiscoenol A and epichlorohydrin Examples include halogenated epoxy compounds such as epoxy compounds, brominated polystyrene, brominated polyphenylene oxide, and the like. The amount added may be a commonly used amount, but it varies depending on the degree of flame retardancy required, and is preferably in the range of 1 to 30% by weight, and more preferably 2 to 20% by weight, based on the total composition. The antimony compound (C) used in the present invention is
100 compounds with the chemical structure shown below
It has been heat-treated at a temperature of ℃ or higher. _XNa2O・_Sb2O5・_YH2O ...(1) Here _, X is in the range of 0.1 to 0.8, preferably 0.3 to
It needs to be in the range of 0.7. That is,
If X is less than 0.1, the physical properties of the obtained polyester resin molded article will be poor, which is not preferable. Moreover, if it exceeds 0.8, the flame retardancy will be greatly reduced, which is not preferable. Y is the number of water of crystallization and is usually in the range of 0.25 to 4.0. Such antimony compound (D) is heated to 100°C or higher in advance.
Preferably, it needs to be heat-treated at a temperature of 300°C or higher. If no heat treatment or heat treatment at less than 100° C. is performed, the molecular weight of the obtained polyester resin composition is significantly reduced and a good molded article cannot be obtained. This is thought to be because crystal water or adhering water of the antimony compound (C) is released during the melt-mixing process, resulting in hydrolysis of the polyester. Further, as mentioned above, since the heat-treated antimony compound (C) also has relatively high hygroscopicity, it is desirable to pay attention to moisture-proofing when storing it prior to melt-kneading. The amount of the antimony compound (C) added is preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight, based on the total composition. In the present invention, the mixture of components (A), (B), and (C) can be obtained by melt-kneading using an extruder or injection molding machine at a temperature higher than the melting point of the polyester (A) component. . The extruder or injection molding machine is
It is preferable to have a vent mechanism to suppress the influence of moisture absorption of the antimony compound (C). The flame-retardant polyester resin composition obtained according to the present invention may contain additives other than those mentioned above in order to impart other required properties. Typical examples of these additives include inorganic reinforcing agents of various properties. For example, fibrous reinforcing agents such as glass fiber, carbon fiber, potassium titanate fiber, and wollastonite, spherical reinforcing agents such as glass beads, plate-like reinforcing agents such as glass flakes, talc, and mica, and feldspar, calcium carbonate, and silica. Examples include amorphous reinforcing agents such as. The amount added is preferably 0 to 60% by weight based on the total composition. Other additives include heat stabilizers (e.g. phosphorus compounds, etc.), antioxidants (e.g.
(phenol compounds, etc.), crystal nucleating agents (for example, metal salts of organic acids), mold release agents, coloring agents, ultraviolet absorbers, antistatic agents, and the like. Additionally, the combined addition of a diepoxy compound, which is generally added to improve the strength of polyester, is also effective in improving properties. Furthermore, addition of other types of polymers, particularly polycarbonate, polyolefins, acrylic elastomers, etc., is effective in improving the impact strength of the polyester composition. <Effects of the invention> The composition of the present invention can be used as a molding machine,
It is particularly preferably used as a material for injection molding and extrusion molding. <Examples> The present invention will be explained in detail below using examples. The main characteristics were measured as follows. Flame retardancy: UL standard Subject 94 Tensile strength: ASTM standard D-638 Tensile elongation at break: ASTM standard D-638 Melting point: Measure the endothermic peak temperature when heating at a rate of 20°C/min using a DSC measuring device Crystal Temperature: Melt and hold at 290°C for 3 minutes using a DSC measuring device, then measure the exothermic peak temperature when the temperature is lowered at a rate of 20°C. Example 1 and Comparative Examples 1 to 4 Intrinsic viscosity [η] (O-chloro Pellets of dried polybutylene terephthalate Y (hereinafter abbreviated as PBD) have an intrinsic viscosity [η] (measured at 35°C using O-chlorophenol as a solvent) of 0.63. Dry pellets of polyethylene terephthalate (hereinafter abbreviated as PET), brominated polycarbonate (average degree of polymerization 18) obtained from tetrabromobisphenol A and phosgene, dried at 300°C for 2 hours as shown in Table 1 beforehand. The antimony compound and glass fiber were mixed in a V-type blender in the proportions shown in Table 1, and this was mixed in a V-type blender equipped with a vent mechanism.
The mixture was supplied to a 65 mmφ extruder and pelletized at a cylinder temperature of 270°C to obtain pellets for molding. After drying the pellets at 130°C for 3 hours, the pellets were molded using a 5-ounce injection molding machine at a cylinder temperature of 260°C.
Molded products were made for characteristic evaluation at 290°C and a mold temperature of 80°C. Table 1 shows the properties evaluated using this molded article. For comparison, molded articles were obtained in the same manner as in Example 1 using resin compositions having the compositions shown in Table 1, and their properties were evaluated. The results are shown in Table 1. It can be seen from Table 1 that the composition of the present invention shown in Example 1 provides a molded article with excellent flame retardancy and strength characteristics, and also has stable moldability over a wide molding temperature range.

【table】

[Table] Examples 2 to 4 and Comparative Examples 5 to 6 Characteristics were evaluated in the same manner as in Example 1, except that the brominated polycarbonate in Example 1 was replaced with brominated polystyrene, and the antimony compound was replaced with the compound shown in Table 2. A molded product was obtained. The evaluation results are shown in Table 2.

【table】

[Table] Examples 5 to 6 and Comparative Examples 7 to 8 Molded bodies for evaluation were molded in the same manner as in Example 1, except that the drying conditions for the antimony compound were changed as shown in Table 3. The results are shown in Table 3. Composition PBT ([η] = 1.05) 60 weight percent PET ([η] = 0.82) 20 〃 Brominated polycarbonate 14 〃 Antimony compound 6 〃 (1/2Na ₂ O・Sb ₂ O ₅・4H ₂ O)

[Table] Table 3 shows that molded products with good properties can be obtained by heat treating antimony compounds.

Claims (1)

[Claims] 1. At least two types of thermoplastic polyester (A)
, an organic halogen compound (B), and an antimony compound (C), wherein the antimony compound
A flame-retardant polyester resin composition in which (C) is a compound having the chemical structure shown in (1) below, which is heat-treated at a temperature of 100°C or higher. XNa ₂ O・Sb ₂ O ₅・YH ₂ O ...(1) (However, in the formula, X is 0.1 to 0.8, Y is the number of crystal water and is 0.25 to 4.0.) 2 Antimony compound (C) The flame-retardant polyester resin composition according to claim 1, which has been heat-treated at a temperature of 300°C or higher.