JPH0225381B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant polystyrene resin composition. Specifically, the present invention relates to a flame retardant composition containing a polystyrene resin and a resorcinol polyphosphate compound. Although polystyrene resin compositions are used in large quantities in various fields due to their excellent properties, they have the disadvantage of being easily flammable, so they are often not the most suitable material for some fields of use. For example, it is unsuitable for parts of electrical products or office equipment that could be extremely dangerous if they continue to burn. Alternatively, if it is made into a foamed molded product, this disadvantage of combustibility will be noticeable, so its use will naturally be limited even though it has excellent heat insulation and sound absorption properties for applications such as building materials. It has the disadvantage that it cannot be obtained. In recent years, due to the need for fire safety, the demand for flame retardant properties for these resins has become increasingly important, and the U.S. UL (Underwriters Laboratory) standards for home appliances in particular have become stricter over the years. That is, there is a strong demand for polystyrene resins that do not cause sparks. Various methods have been proposed or attempted in the past in order to impart flame retardancy to such polystyrene resins. As a general method, it is known that flame retardation can be achieved by mixing organic flame retardants such as organic halogen compounds and halogenated phosphate esters, or a combination of these and inorganic flame retardant aids such as antimony trioxide. There is. However, whichever method is used, it is possible to reduce the impact strength or softening point of the resin composition, or significantly narrow the allowable range of temperature control during extrusion and molding, resulting in incorrect control. There are disadvantages in that the compound may decompose to produce colored pellets or molded products, or the flame retardant effect may no longer be satisfactory due to decomposition. Furthermore, drippings, ie sparks, occur during combustion. In order to obtain these compositions with excellent flame retardancy and no drippings, a large amount of the flame retardant must be mixed in. As a result, the excellent mechanical properties of polystyrene resins It has drawbacks that seriously reduce any or all of the physical properties and other desirable properties. In order to prevent this combustion dripping, a method of mixing an inorganic filler has also been proposed, and has achieved some degree of effectiveness. however,
This method has the disadvantage that it loses some of the excellent properties possessed by polystyrene resins, and is still not sufficient. In addition, in the case of halogen- or phosphorus-containing flame retardants, simply having a high halogen or phosphorus content in the substance does not necessarily mean that the effect of imparting flame retardancy is large; Alternatively, a higher phosphorus content does not necessarily mean a greater effect. Therefore, it is extremely difficult to predict which chemical structure of the substance to use will have the greatest flame retardant effect and will not adversely affect the properties of the final product. The present inventors conducted extensive research in search of an excellent flame retardant for polystyrene resin compositions, and found that resorcinol polyphosphate compounds not only have an extremely excellent flame retardant effect but are also known to have an excellent flame retardant effect. It has been found that combustion drippings are greatly suppressed compared to phosphate compounds. Furthermore, this resorcinol compound is uncolored, has low volatility, and produces extremely little smoke and bleed during processing.
It was found that it has excellent compatibility with polystyrene resins. In particular, the hydroquinone polyphosphate compound, which is a homologous compound, becomes noticeably colored during processing, and
The excellent effect of this resorcinol polyphosphonate compound is unique in that it causes bloom. That is, the present invention provides a flame-retardant resin composition by blending a polyphosphate compound represented by the following general formula () with a polystyrene resin. (In the formula, R represents a hydrogen atom or a methyl group, and n
indicates 1 to 5. ) The polystyrene resin in the present invention refers to a polymer of styrene and styrene derivatives such as α-substituted styrene such as α-methylstyrene, vinyltoluene, and nuclear-substituted styrene such as low-chlorostyrene; Monomers copolymerizable with this, such as acrylonitrile, acrylic acid and methacrylic acid, vinyl compounds such as their methyl or ethyl esters, heterocyclic compounds such as vinylpyridine and vinylcarbazole, and conjugated diene compounds such as butadiene and isoprene. It means an interpolymer obtained from one or a mixture of two or more monomers such as the following; and a thermoplastic resin composition that essentially contains the above-mentioned polymer as a main component. The content of the phosphate compound that exhibits the effects of the present invention is 0.1 to 30% by weight, preferably 1 to 15% by weight based on the total composition. The flame-retardant resin composition of the present invention can be prepared by mixing the predetermined components using a conventional method such as a mixing roll, a kneader, a Banbury mixer, or an extruder. In the present invention, as in the usual case, during kneading,
UV absorbers, plasticizers, colorants,
Various additives such as fillers and stabilizers may be mixed in without any problem. Since the flame-retardant resin composition according to the present invention has various advantages and characteristics as described above, it is expected to have a wider range of applications. In particular, it offers new uses because it has excellent flame retardancy and no combustion drippings. EXAMPLES Hereinafter, the present invention will be specifically illustrated by examples, but the scope of the present invention is not limited thereby. Example 1 High impact polystyrene (Dialex HT-
Add 10 parts by weight of the organic phosphate compound listed in Table 1 to 100 parts by weight (88 manufactured by Mitsubishi Monsanto),
After blending the mixture uniformly for about 15 minutes using a V-type blender, pellets were formed using a 40 m/mφ extruder, and the pellets were made into specified test pieces using a molding machine with a capacity of 4 ounces. Flame retardancy was evaluated in accordance with the test method specified in UL-94, and the time from initial ignition to extinguishment was determined for each of five test pieces, and the average value was recorded.
Further, the heat distortion temperature was measured according to ASTM standard D648. The results are shown in Table 1.

【table】

[Table] Example 2 Polystyrene (Styron 666 manufactured by Asahi Dow) 100
To the parts by weight, 5 parts by weight of hexabromobenzene and 5 parts by weight of the organic phosphate compound listed in Table 2 were added, test pieces were prepared in the same manner as in Example 1, and flame retardancy was evaluated. The results are shown in Table 2.

[Table] Example 3 AS resin (Estyrene AS-20 manufactured by Nippon Steel Chemical Co., Ltd.)
To 100 parts by weight, 4 parts by weight of decabrom biphenyl ether and 2 parts by weight of the organic phosphate compound listed in Table 3 were added, test pieces were prepared in the same manner as in Example 1, and flame retardancy was evaluated. The results are shown in Table 3.

[Table] Example 4 ABS resin (Blendex111; manufactured by Ube Saikon Co., Ltd.)
To 100 parts by weight, 5 parts by weight of tetrabromobisphenol A and organic phosphate compound 3 listed in Table 4
A test piece was prepared by adding parts by weight and injection molding at 230°C. The degree of coloring of this test piece and the flame retardance measured in the same manner as in Example 1 were evaluated. In addition, the surface condition of the test piece after being left at room temperature for 10 days was observed to see if there was any bleeding. The results are shown in Table 4.

[Table] If it is, it indicates that the coloring is severe.

Claims (1)

[Scope of Claims] 1. A flame-retardant polystyrene resin composition comprising a polystyrene resin and a polyphosphate compound represented by the following general formula (). (In the formula, R represents a hydrogen atom or a methyl group, and n
indicates 1 to 5. )