JPH0639559B2 - Stabilized flame-retardant styrene resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-stabilized flame-retardant styrene resin composition.

Since styrene resins have excellent physical properties, they are used in various applications such as electric appliances, upholstery and building materials. However, since styrene-based resins are flammable, flame-retardant regulations are imposed for some applications.

[Conventional technology]

To make the styrene resin flame-retardant, flame retardants such as polychlorinated organic compounds, polybrominated organic compounds, antimony trioxide, and phosphorus compounds are added. Of these, halogen-based flame retardants are particularly effective and are often used. However, halogen-based flame retardants are unstable at high temperatures and are easily decomposed, so styrene-based resins containing them are colored during processing.

Therefore, in order to prevent coloration due to these flame retardants, a conventional method of adding a dialkyltin maleate polymer (Japanese Patent Publication No. 47-22090), a metal maleate salt and / or a maleic acid monoester salt are added. Method (JP-A-54-669)
56), a method of adding hydrotalcite (JP-A-60)
-86143) is known.

[Problems to be solved by the invention]

However, since the above styrene resin has a particularly high processing temperature (200 ° C. or higher), thermal stability at high temperature is not sufficient by any method, and development of an excellent stabilizer for preventing this thermal deterioration is desired. There is.

[Means for solving problems]

As a result of various studies, the present inventors have found that by using an organic tin thiodipropionate or / and an organic tin dithiodipropionate and hydrotalcite in combination, a thermoplastic resin containing a halogen-based flame retardant can be treated at a high temperature. They have found that they can be heat-stabilized during processing and have reached the present invention.

That is, the present invention provides (a) a dialkyltin thiodipropionate and a monoalkyltin when heat-stabilizing a flame-retardant resin comprising 100 parts by weight of a styrene resin and 1 to 50 parts by weight of a halogen-based flame retardant. 0.01 to 5 parts by weight of one or more of thiodipropionate, dialkyltin dithiodipropionate and monoalkyltin dithiodipropionate, and 0.01 to 5 parts by weight of (b) hydrotalcites. The flame-retardant styrene resin composition is stabilized, which is characterized in that

As the dialkyltin dithiodipropionate to be added to the flame-retardant resin in the present invention to heat-stabilize, for example, a compound having a repeating unit of the structure of the general formula [1] is a monoalkyltin thiodipropionate. Examples of the dialkyltin dithiodipropionate include compounds having the repeating structure of the general formula [2] as repeating units, and examples of the compounds having the repeating unit of the general formula [3] include monoalkyltin dithio Examples of the dipropionate include compounds having the network structure of the general formula [4] as a repeating unit.

In the formula, R represents an alkyl group such as a methyl group, a butyl group, an octyl group and a lauryl group.

In the present invention, hydrotalcites used in combination with the above organic tin thiodipropionate or (and) organic tin dithiodipropionate for thermal stabilization of the flame retardant resin include, for example, compounds represented by the general formula: (However, O <x ≦ 0.5, m is a positive number.) A hydrated double salt compound composed of magnesium and aluminum represented by the formula (2) may be used, and may be a natural product or a synthetic product.
These are commercially available.

The addition amount of the organic tin thiodipropionate or / and the organic tin dithiodipropionate in the present invention is 0.01 to 5 parts by weight with respect to 100 parts by weight of the styrene resin. The amount of hydrotalcites used together is 0.01 to 5 parts by weight with respect to 100 parts by weight of the styrene resin. If it is used below the lower limit of this amount, the thermal stability is not improved, and if it is above the upper limit, it is uneconomical.

Examples of the styrene resin used in the present invention include polystyrene, methylstyrene mainly containing styrene, divinylbenzene, butadiene, acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, acrylonitrile-butadiene-methyl. Examples thereof include a styrene terpolymer, a mixture of butadiene and styrene or acrylonitrile, and a mixture of styrene and acrylonitrile.

In the present invention, a halogen-based flame retardant of a polychlorinated organic compound and a polybrominated organic compound is used for flame retarding the styrene resin. Examples of the polychlorinated organic compound include polychloroparaffin, chlorinated polyethylene, perchloropentacyclodecane, tetrachlorophthalic anhydride, chloroendoic acid, hexachloroethane, hexachlorocyclohexane, and pentachlorobenzene. Examples of such compounds include bromides of aliphatic hydrocarbons such as tetrabromoethane, tetrabromobutane, tribromopropane, tribromotrichlorocyclohexane, tetrabromodichlorocyclohexane, pentabromocyclohexane, tetrabromocyclooctane, hexabromocyclododecane, bis ( Bromides of alicyclic hydrocarbons such as dibromocyclohexyl) -1,2-dibromoethane, hexabromobenzene, decabromodiphenyl, decabromodiphenyl ether Le, hexabromodiphenyl ether, pentabromodiphenyl ether, pentabromotoluene, pentabromodiphenyl ethylbenzene, penta-bromophenol, tribromophenol,
1,2-dibromopropyltribromophenyl ether, tetrabromobisphenol A, tetrabromobisphenol S, tetrabromophthalic anhydride, 1,2-
Examples thereof include aromatic bromides such as bis (pentabromophenoxy) ethane, bis (tribromophenoxy) ethane, polydibromophenylene oxide, and carbonate oligomers of tetrabromobisphenol A.

In the composition of the present invention, if necessary, an antioxidant, an ultraviolet absorber, boric acid, a boric acid ester, an epoxy compound, a metallic soap, a diketone compound, a flame retardant other than a halogen type (for example, a phosphorus compound, antimony trioxide, borohydride). Acid salt, aluminum hydroxide, etc.), smoke remover (smokeless agent), pigment, filler,
A lubricant or the like can be added.

[Action]

By adding one or more of alkyltin thio or dithiodipropionate, the styrene resin containing halogen flame retardant can be thermally stabilized, but according to the present invention, if the hydrotalcites are further reduced, The thermal stability to the resin was improved, and processing at high temperature was extremely easy. Such effects cannot be achieved with metal salts of other carboxylic acids.

〔Example〕

Next, the present invention will be described with reference to examples, but parts in the examples represent parts by weight.

Example 1 100 parts of acrylonitrile-butadiene-styrene resin (Cycolac Ex211 manufactured by Ube Cycon), 10 parts of tetrabromobisphenol A, 5 parts of antimony trioxide, 0.5 parts of hydrotalcite (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) and 1.0 part of the stabilizer shown in Table 1 below was added and mixed with a kneading roll at 150 ° C. for 4 minutes to prepare a sheet having a thickness of 0.5 mm. The sheet was sandwiched between aluminum plates and a heat-stability test was conducted in a gear oven maintained at 220 ° C.

The numbers in the table represent the following evaluations.

1: White 2: Light yellow 3: Yellow 4: Light brown 5: Brown 6: Black brown The results are shown in Table 1.

Example 2 100 parts of styrene resin (Styron 666, manufactured by Asahi Kasei Co., Ltd.), 25 parts of hexabromocyclodecane, 2 parts of titanium oxide, 0.5 part of dibutyltin thiodipropionate, and hydrotalcite shown in Table 2 below (all are Kyowa). (Manufactured by Kagaku) was added and mixed with a kneading roll at 135 ° C. for 3 minutes to prepare a sheet having a thickness of 0.5 mm. This sheet is sandwiched between aluminum plates, 225
A thermal stability test was performed in a gear oven maintained at ° C.

The numbers in the table represent the following evaluations.

1: White 2: Light gray 3: Gray 4: Black gray 5: Black The results are shown in Table 2.

[Effect of the Invention] As is clear from the results of the thermal stability test of Examples 1 and 2, the flame retardant resin contains one or more alkyltin thio or dithiodipropionate, and hydrotalcites. When added together, the thermal stability was incrementally improved as compared with the use of either one of them or the use of a known maleic acid derivative. These effects are achieved only by the constitution of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 55/02 LMC 7142-4J // C08G 79/12 NUR 7308-4J

Claims (1)

[Claims] 1. When heat-stabilizing a flame-retardant resin comprising 100 parts by weight of a styrene-based resin and 1 to 50 parts by weight of a halogen-based flame-retardant, (a) a dialkyltin thiodipropionate or a monoalkyltin thiol. 0.01 to 5 parts by weight of one or more of dipropionate, dialkyltin dithiodipropionate and monoalkyltin dithiodipropionate, and 0.01 to 5 parts by weight of (b) hydrotalcites. A stabilized flame-retardant styrene-based resin composition, which is added together.