JPS5917739B2 - Flame retardant polystyrene resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition in which the anti-trip properties of a flame-retardant polystyrene resin are improved. The present invention relates to a combusted polystyrene resin composition.

Polystyrene 25 such as polystyrene, AS, ABS
Polystyrene resins made of homopolymers, copolymers, or blended polymers are flammable thermoplastic resins that are difficult to use in electrical equipment parts, exterior parts, building materials, furniture, and other fields. Combustion is required.

30 Polystyrene resins are generally made flame retardant by adding a flame retardant, and reactive flame retardants may also be used.

Various compounds are known as flame retardants, and for example, halogen-containing compounds, phosphorus-containing compounds, nitrogen-containing compounds, etc. are often used. Furthermore, it is common practice to use a flame retardant aid such as antimony oxide in combination with the flame retardant. These flame retardants have the effect of preventing polystyrene resin from igniting and burning, and quickly extinguishing the flame when it breaks apart.

However, in order to make polystyrene resin flame retardant, simply reducing its combustibility is not sufficient. When polystyrene-based resin burns, a phenomenon in which droplets of molten resin (droplets) drip is observed. Dripping droplets can cause burns and contamination, and especially if the droplets are ignited. Therefore, in order to make polystyrene flame retardant, it is thought that measures to prevent these droplets from dripping, that is, measures to improve trip resistance.For example, the standard synthetic resin retardant used in the United States In the UL-94 standard, which is a flame performance test method, one of the requirements for being ranked V-0 is the absence of dripping substances. Therefore, the present inventor conducted various research studies on measures to prevent the dripping of flame-retardant polystyrene resin, that is, to improve the anti-trip properties of flame-retardant polystyrene resin. In particular, we found that the addition of a small amount of polyolefin resin can significantly improve the anti-trip properties.The reason for this surprise is that polystyrene resins and polyolefin resins are not compatible, and the polyolefin resin itself This is because it does not have anti-trip properties. However, when 15% by weight or less, especially 10% by weight or less of polyolefin resin is added to polystyrene resin, the anti-trip properties are significantly improved, and this fact is demonstrated in the examples below. It is clear from the above.The present invention is based on this fact,
That is, a flame retardant with improved trip resistance characterized by adding 0.1 to 15% by weight of a polyolefin resin based on the polystyrene resin to a polystyrene resin composition made flame retardant with a flame retardant. It is a polystyrene-based resin composition. The polyolefin resin in the present invention is a hydrocarbon polymer having one aggregating unsaturated group such as ethylene or propylene, and is substantially polyethylene or polypropylene, and is incompatible with polystyrene resins. . These polyolefin resins are not compatible with polystyrene resins, and conventionally, blending with polystyrene resins has not been carried out. Even if a polyolefin resin is added to a polystyrene resin, the mechanical properties of the polystyrene resin, such as impact resistance and creep resistance, do not improve, but rather deteriorate. Also in the present invention, since adding a large amount of polyolefin resin deteriorates the mechanical properties of polystyrene resin, it is necessary to keep the deterioration within a range where it cannot be ignored, specifically excluding flame retardants, flame retardant aids, and additives. It is necessary that the amount is 15% by weight or less, particularly preferably 10% by weight or less, based on the polystyrene resin. It is not clear why polyolefin resins improve the trip resistance of polystyrene resins. Polyolefin resins with flame retardants added are inherently more prone to tripping than polystyrene resins and other resins.
It does not itself have anti-trip properties. There is also a proposal to add polymethyl methacrylate to ABS to improve its anti-trip properties, but compared to this, the polyolefin resin of the present invention is much more effective.
Moreover, the amount added can be small. There are also proposals to add vinyl chloride resin or silicone rubber to certain resins, but in order to improve trip resistance, it is necessary to add a large amount of these resins, which may deteriorate the mechanical properties of the added resin. , and has the disadvantage that not only the moldability etc. are lowered but also the cost is relatively high. Other known methods include adding fibrous fillers such as glass fiber and asbestos, and adding fillers such as talc, calcium carbonate, and alumina hydrate. In the latter case, a large amount of filler is required, resulting in deterioration of mechanical properties and moldability. In the present invention, the amount of polyolefin resin added to polystyrene resin is usually 2
~5% by weight is sufficient, and since the amount added is small, there is no risk of deteriorating the mechanical properties and moldability of the polystyrene resin.

However, if the amount added is too small, the anti-trip properties cannot be fully exhibited, so the amount of polyolefin resin added is 0.
．． 1 to 15% by weight is preferred, especially 0.5 to 10% by weight
is appropriate. The polystyrene resin used in the present invention is a thermoplastic resin whose main component is polystyrene homopolymer or copolymer.

Polystyrenes include general polystyrene, high impact polystyrene, and other resins whose main component is polystyrene. Preferred is general purpose polystyrene or high impact polystyrene. These polystyrene resins are easily flammable,
Flame retardants are required for flame retardancy. Flame retardants include halogen-containing compounds, phosphorus-containing compounds, nitrogen-containing compounds, and other flame retardants, with halogen-containing compounds being preferred.

Chlorine or bromine is effective as the halogen.・・・
Among the rogen-containing compounds, bromine-containing compounds are preferred, and compounds having an aromatic nucleus to which bromine is bonded are particularly preferred. Examples of polybrominated aromatic compounds include tetrapromobisphenol A (TBA), tetrapromobisphenol S (TBS), and hexabromobenzene (HBB).
),. decapromodiphenyl ether (DBDPO),
Decabromodiphenyl (DBDP), tetrabromo phthalic anhydride, or derivatives thereof, such as TBA (
These include halo)alkyl ethers, TBA-hydroxyalkyl ethers, TBA-S-triazine compounds, and various other compounds. In addition, various halogen-containing compound flame retardants can be used, such as chlorinated aromatic hydrocarbon compounds, halogenated aliphatic hydrocarbon compounds, halogenated alicyclic hydrocarbon compounds, and halogenated inorganic compounds. . Phosphorus-containing compounds are mainly esters of various phosphoric acids that do not contain or contain halogens, such as trialkyl phosphates, triaryl phosphates, trihaloalkyl phosphates, triaryl phosphites,
Examples include various organic phosphorus compounds such as polyphosphonates, and inorganic phosphorus compounds such as ammonium polyphosphate.

In addition, combinations of the above-mentioned flame retardants and various flame retardants other than those mentioned above are used to make polystyrene resin flame retardant. Furthermore, flame retardant aids are often used in combination with flame retardants. Antimony-based compounds such as antimony trioxide are most widely used as flame retardant aids, and other compounds include boron-containing compounds and other metal-containing compounds. The polystyrene resin of the present invention includes the above polyolefin resin,
In addition to flame retardants and flame retardant aids, various additives may be added.

Additives include fillers, reinforcing fiber fillers, stabilizers, colorants, mold release agents, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, and other additives, as required. One or more types may be added. In addition, methods conventionally used to improve anti-trip properties, such as fillers such as talc, calcium carbonate, and alumina hydrate,
Fine granular fillers such as fine silica, fibrous fillers,
Additions such as anti-trip polymers can be used in conjunction with the polyolefin resins of the present invention to further improve the anti-trip properties. The amount of additives containing flame retardants and flame retardant aids is not particularly limited, but the amount of flame retardants and flame retardant aids added is 1 to 40% by weight based on the polystyrene resin that does not contain other additives. is appropriate, particularly preferably 5 to 30
Weight%.

The amount of additives other than flame retardants and flame retardant aids added is not particularly limited, but the amount of additives other than fillers or reinforcing fiber fillers is usually small. The flame-retardant polystyrene resin with improved trip resistance of the present invention can be used in various applications, but is preferably used in electromechanical parts and their exterior parts.

Examples include television cabinets, television front panels, radio, tape recorder, stereo cabinets, and other parts and exterior parts. It is also used in fields that require flame retardancy, such as office equipment and miscellaneous goods. EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples.

Example 1 Comparative Example 1 82 parts by weight of i-impact polystyrene (trade name: Styron 492), 3 parts by weight of polypropylene (PP), 1 part by weight of decabromodiphenyl ether (DBDPO)
1 part by weight and 4 parts by weight of antimony trioxide (Sb2O3) were kneaded at 220°C using a single screw kneading extruder to form pellets.

The pellets were injection molded at 200° C. using an injection molding machine to form test pieces with thicknesses of 1/8 inch and 1/16 inch. For this test piece, the trip start time (seconds) was measured by continuously applying flame until tripping occurred according to the vertical test method of UL-94 standard, and
The grade was determined. As the polypropylene, Mitsubishi Noblen BC-6 (melt index: 2, impact resistance grade) and Mitsubishi Noblen BC-8 (melt index: 1.2, impact resistance grade) were used. On the other hand, similar tests were conducted on a sample in which 85 parts by weight of high-impact polystyrene was used without adding polypropylene, and a sample in which a thermoplastic resin other than polyolefin resin was added instead of polypropylene. The result is the first
Shown in the table. It should be noted that the trip start time showing the anti-trip property is required to be at least 20 seconds, and the longer this time is, the more preferable it is. Moreover, V-0 is the most preferable UL-94 grade, and the flame retardance decreases from V-1 to V-2. Comparative example 2 Polypropylene (product name: Kibi Noblen MH-4) 7
A flame-retardant polypropylene composition consisting of 0 parts by weight, 26 parts by weight of DBDPO, and 34 parts by weight of Sb2O; and a flame-retardant polypropylene composition consisting of 70 parts by weight of polypropylene (trade name: Kibishi Noblen 1BC-8), 24 parts by weight of DBDPO, and 36 parts by weight of Sb2O. The anti-trip properties were measured in the same manner as in Example 1, and the results are shown in Table 2.

It can be seen that polypropylene itself does not have anti-trip properties. Example 2 Comparative Example 3 79 parts by weight of high impact polystyrene, 6 parts by weight of low density polyethylene, DBDPO
II parts by weight, Sb, O.

A test piece was prepared in the same manner as in Example 1 using 4 parts by weight,
Its flame retardancy and trip onset time were measured.

As a comparative example, similar measurements were made using only polymethyl methacrylate resin and high impact polystyrene instead of low density polyethylene. The results are shown in Table 3. Example 3 Comparative Example 4 The following composition was tested for anti-trip properties and flame retardance in the same manner as in Example 1. The results are shown in Table 4.

The extrusion kneading temperature was 220°C and the injection molding temperature was 20°C.
It is 0°C. Table 5 shows the results obtained in the same manner as in Example 1 using general-use polystyrene.

Claims (1)

[Claims] 1. In a polystyrene resin composition made flame retardant with a flame retardant, the polystyrene resin is polystyrene made of a styrene homopolymer or high impact polystyrene.
Improvement of anti-drip properties of polystyrene, characterized by adding a polyolefin resin which is composed of 0.1 to 15% by weight of polyethylene or polypropylene based on the polystyrene resin and is incompatible with the polystyrene resin. flame retardant polystyrene resin composition. 2. The flame-retardant polystyrene resin composition according to claim 1, wherein the amount of polyolefin resin added is 0.5 to 10% by weight based on the polystyrene resin. 3 Addition amount of flame retardant is 1 to 1 to polystyrene resin
40% by weight of the flame retardant polystyrene resin composition according to claim 1. 4 The amount of flame retardant added is 5 to 50% relative to polystyrene resin.
The flame retardant polystyrene resin composition according to claim 3, characterized in that the content is 30% by weight. 5. The flame-retardant polystyrene resin composition according to claim 1, wherein the flame retardant is a halogen-based flame retardant containing chlorine or bromine. 6 Claims characterized in that the halogenated flame retardant is a halogenated aromatic hydrocarbon flame retardant in which a halogen is bonded to an aromatic nucleus, or a halogenated aromatic hydrocarbon derivative flame retardant containing a halogenated aromatic nucleus. 5. Flame-retardant polystyrene resin composition. 7. The flame-retardant polystyrene resin composition according to claim 1, wherein the flame retardant is a phosphorus-based flame retardant that may or may not contain a halogen. 8. The flame-retardant polystyrene-based resin composition according to claim 1, characterized in that an antimony compound-based flame retardant aid is used in combination as part of the flame retardant.