JPS6128696B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant polystyrene resin composition with an excellent balance of mechanical properties and heat resistance. In recent years, there has been a remarkable development in various office equipment, which has been called the office automation revolution. Most of this type of office equipment is electrical equipment with built-in live parts, and is of course subject to various regulations, such as self-extinguishing properties, prevention of dripping of decomposed molten material, etc., as well as the conditions of use. As a result, the device itself and its surroundings will be exposed to high temperatures.
It has become necessary to have heat resistance to the extent that the product does not lose its shape even under such conditions. Polystyrene resins such as polystyrene and ABS resins are widely used for the above purposes, and various means for making them flame retardant have been studied. Among them, flame retardants that can impart relatively high flame retardancy to polystyrene resins and have heat resistance include (1) halogenated diphenyl ether compounds such as decabrom diphenyl ether (DBE) (Japanese Patent Publication No. 52-32898 (2) Low molecular weight brominated polycarbonate (Japanese Patent Publication No. 56-25953)
No. 2) is known. However, the flame retardant in (1) above has an extremely high melting point of 300 to 315°C, has poor dispersibility in polystyrene resin, and significantly impairs the mechanical properties and appearance of molded products, so it has a very high melting point during melt-kneading. This method is disadvantageous in terms of cost, and also has the problem of unavoidably lowering the heat resistance of the resin. In addition, although the flame retardant (2) has good heat resistance, it still has problems with its dispersibility in resins, and not only can it not be expected to have sufficient mechanical properties, but it also adheres to the mold during molding, resulting in molded products. It has a fatal defect that deteriorates the surface appearance. Therefore, the present inventors investigated with the aim of obtaining a polystyrene-based resin composition that has a high degree of flame retardancy as well as an excellent balance between mechanical properties and heat resistance, and found that halogenated diphenyl ether and halogen The present inventors have discovered that by blending both bisphenol-type polycarbonate oligomers in a specific ratio, the drawbacks of both flame retardants can be mutually improved and the above object can be effectively achieved, and the present invention has been achieved. That is, the present invention includes (A) at least one type of halogenated diphenyl ether, (B) at least one type of halogenated bisphenol type polycarbonate oligomer, and
(C) antimony trioxide, (A) is 5 to 20 parts by weight, (B) is 1 to 15 parts by weight, (C) is 1 to 20 parts by weight, and the total amount of (A) and (B) is The present invention provides a flame-retardant wood composition characterized in that it is blended in a proportion of 6 to 35 parts by weight. According to the present invention, especially high melting point and poor dispersibility
(A) The amount of halogenated diphenyl ether added can be reduced, and by using (B) halogenated bisphenol type polycarbonate oligomer in combination, (A)
The dispersibility of both (A) and (B) is synergistically improved, resulting in a polystyrene with much improved flame retardancy, heat resistance, and mechanical properties than when each of (A) and (B) is used alone. based resin compositions can be obtained. The polystyrene resin used in the present invention is a polymer containing an aromatic vinyl compound as a main component, such as polystyrene, α-methylstyrene-
Acrylonitrile copolymer, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-acrylonitrile-methyl methacrylate copolymer, and rubber modified resins in which these hard resins are radically bonded to rubber components. Can be mentioned. The rubber modified resins mentioned here are polybutadiene, styrene-butadiene rubber,
It is a two- or three-layer resin in which the above hard resin is bonded to a rubber component such as acrylonitrile-butadiene rubber, acrylic rubber, or ethylene-propylene-diene rubber. Specific examples include acrylonitrile-butadiene-styrene copolymer (ABS resin). ), acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-methyl methacrylate-butadiene-styrene copolymer, acrylonitrile-acrylic rubber-styrene copolymer, acrylonitrile-ethylene rubber-styrene copolymer, etc. can be mentioned. These polystyrene resins are produced by conventional suspension polymerization methods, bulk polymerization methods, emulsion polymerization methods, bulk-suspension polymerization methods, and the like. The halogenated diphenyl ether (A) used in the present invention is a compound represented by the following general formula (). However, in the above formula (), X is Cl or
Br, e and f each represent an integer of 2 to 5. Examples of the compound represented by the above general formula () include pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, etc. Among them, decabromodiphenyl ether (DBE) is preferably used.
The amount of halogenated diphenyl added is 5 to 20 parts by weight, preferably 6 to 15 parts by weight, per 100 parts by weight of the polystyrene resin. If it is less than 5 parts by weight, a sufficient flame retardant effect cannot be obtained, and if it exceeds 20 parts by weight,
This is not preferred because it causes poor dispersion and insufficient mechanical properties and heat resistance. Further, the halogenated bisphenol type polycarbonate oligomer (B) used in the present invention is a compound represented by the following general formula () or (). However, in the above () or formula, X is Cl
or Br, R is a _C1-5 alkyl group, carbonyl group, -O-, -S-, _-SO2- , g is an integer of 1-4, h is an integer of 1-5, and l is a repeating unit. 1 to 50, m and n are 0.75<Mm×m/Mm×m+M
Indicates an integer satisfying m×n <0.99 and 3m+n50. Also here Mm is the repeating unit

Weight of [formula], Mn is the repeating unit

The weight of [Formula] is shown respectively. The halogenated bisphenol type polycarbonate oligomer represented by the above general formula () or () is produced by reacting a halogenated bisphenol compound with phosgene and/or a halogenated bisphenol compound, a bisphenol compound, and a halogenated phenol compound with phosgene. This is the compound obtained. (B) represented by the above general formula () or ()
The appropriate amount of the halogenated bisphenol type polycarbonate oligomer to be added is 1 to 15 parts by weight, preferably 2 to 12 parts by weight, per 100 parts by weight of the polystyrene resin, and if it is less than 1 part by weight, the desired effect cannot be obtained. Moreover, if it exceeds 15 parts by weight, not only the mechanical properties will deteriorate, but also the surface appearance of the molded product will be impaired, which is not preferable. In addition, it is important that the total amount of the flame retardants (A) and (B) is 6 to 35 parts by weight, especially 10 to 25 parts by weight, based on 100 parts by weight of the polystyrene resin. If the amount exceeds 35 parts by weight, the mechanical properties and heat resistance of the polystyrene resin will be impaired, which is not preferable. The flame retardant effect when the above flame retardants (A) and (B) are used together can be further enhanced by using antimony trioxide in combination. The amount added is polystyrene resin 100%
1 to 20 parts by weight, preferably 3 to 15 parts by weight
If it is less than 1 part by weight, the flame retardance will not be sufficient, and if it is more than 20 parts by weight, the mechanical properties of the polystyrene resin will be impaired, which is not preferable. At the same time, other flame retardant aids such as boron oxide, zirconium oxide, iron oxide, etc. may be used in combination. The flame-retardant polystyrene resin composition containing the above-mentioned flame retardant and antimony trioxide has sufficient flame retardancy, but if necessary, chlorinated polyethylene may be further added to the composition to improve the flammability test method. CSA (CANADIAN.
STANDARDS.ASSOCIATION) can improve the performance of the standard. Further, the heat resistance, particularly the thermochromic property, of the flame-retardant polystyrene resin composition of the present invention is improved by adding a stabilizer. These stabilizers include phosphorus compounds such as trisnonyl phenyl phosphite and dialkylaryl phosphite, hindered phenol compounds, sulfur-containing compounds such as thioethers, mercaptobenzimidazoles, and thiodipropionic acid esters, tin malates, Tin-based compounds such as tin laurate and dibutyltin monoxide can be used. The amount of these stabilizers added is based on 100 parts by weight of polystyrene resin.
It is 0.01 to 2 parts by weight. Further improvement in heat resistance for the composition of the present invention,
To improve rigidity, fiber materials such as glass fiber, asbestos, calcium metasilicate, potassium titanate, and ceramic fiber can be added, and the amount of these added is usually 5 to 70 parts by weight per 100 parts by weight of polystyrene resin. is within the range of Additionally, fillers such as glass beads, talc, calcium carbonate, aluminum oxide, etc. can be added as well. In order to improve the moldability of the composition of the present invention, stearate (calcium, barium, aluminum, lithium), silicone oil, montan acid wax (ester, half ester, salt), stearate, ethylene bis stearylamide, etc. A lubricant can be added. The amount of these additives is usually 0.05 to 5.0 parts by weight per 100 parts by weight of the polystyrene resin. Furthermore, known additives such as dyes, pigments, plasticizers, ultraviolet absorbers, and foaming agents can be added to the composition of the present invention. The method for producing the composition of the present invention is not particularly limited, and may be extruded using known blending means, for example, by premixing polystyrene resin, flame retardants (A), (B), and antimony trioxide, or without premixing. It is prepared by feeding it into a machine and melting and mixing it. The polystyrene resin composition of the present invention thus obtained has a high degree of flame retardancy as well as excellent heat resistance and mechanical properties, and is useful for various uses such as office equipment and electrical equipment. The effects of the present invention will be explained below with reference to Examples. Note that all percentages and parts in the examples are based on weight. Examples 1 to 15 and Comparative Examples 1 to 4 Flame retardant (A) DBE, flame retardant (B )
(B-1) and (B-2) represented by the following structural formula and antimony trioxide were mixed in a ribbon blender in the proportions shown in Table 1, and further 40
Using an extruder with a φ vent, the mixture was melt-kneaded at 250°C and pelletized. Note that 1 part of dibutyltin dilaurate was added to each composition as a heat stabilizer. The pellets were then used in a 2.50Z injection molding machine to produce combustion test pieces (1/8″ x 1/2″ x 5″ rods for UL and 1/16″ x 1/2″ x 5″ rods for CAS). 1/8″×6″×
8″ plate), Izotsu impact test piece (1/2″×1/2″×
2 1/2″ bar) and heat deformation test piece (1/2″×1/2″×
5"). The combustion test was conducted in accordance with the method specified in UL-95 and CSA C22.2 No.143. The impact strength was
ASTM D-256, heat distortion temperature ASTM D-648
I followed. These results are shown in Table 1. Moreover, Table 1 shows the case where flame retardant (A) or (B) was used alone as a comparative example.

[Table] As is clear from Table 1, the composition of the present invention in which flame retardants (A) and (B) are used in combination is superior to the composition in which flame retardants (A) and (B) are used alone. Excellent flame retardancy can be obtained with a small amount added, and it also has an excellent balance between impact resistance and heat resistance. Example 16 A formulation similar to the composition of Example 6 was further added with chlorinated polyethylene (trade name: Daisolak G-235).
When the same test as in Example 6 was carried out by adding 5 parts of
The CSA was improved to 1/8'' OK, and a composition with excellent mechanical properties such as an impact strength of 20 kg cm/cm and a heat distortion temperature of 83°C was obtained.

Claims (1)

[Claims] 1 For 100 parts by weight of polystyrene resin, (A) at least one halogenated diphenyl ether,
(B) at least one halogenated bisphenol type polycarbonate oligomer and (C) antimony trioxide, (A) is 5 to 20 parts by weight, (B) is 1 to 15 parts by weight,
(C) is 1 to 20 parts by weight and the total amount of (A) and (B) is 6 to 35 parts by weight
A flame-retardant resin composition characterized in that the components are blended in parts by weight.