JPH0567654B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a foamed styrenic resin having excellent flame retardancy. [Prior Art] Although expanded styrene resins are currently used in a wide range of applications, they have the major drawback of being easily flammable. For this reason, various flame retardants have been researched and a number of proposals have been made. This method is not very preferable because it requires the preparation of many different types of polymers, and depending on the type of flame retardant, it is troublesome to control the polymerization. Additive flame retardants, on the other hand, are far more advantageous in these respects, but especially when low molecular weight flame retardants are used, the original properties of the resin, especially heat resistance and mechanical properties, deteriorate. Polymer flame retardants have recently come into use. However, it is not easy to obtain a flame-retardant resin composition that has the required properties in a well-balanced manner, as problems may arise in moldability, appearance of the molded product, etc. depending on the type and amount of flame retardant used. . For example, 2,2-bis(4-allyloxy-3,5-
dibromophenyl) propane (JP-A-53-125457
Publication No.), Hexabromocyclododecane (Special Publication)
43-29658), pentapromomonochlorocyclohexane (Japanese Patent Publication No. 36-6683), and the like are known. Among these, 2,2-bis(4-allyloxy-3,5-dibromophenyl)propane in particular exhibits a unique flame retardant effect on styrene resins, so its usage amount is higher than that of other flame retardants. However, it has the disadvantage that the physical properties of the resin are greatly reduced. In particular, in extrusion foaming using a liquid blowing agent, there was a problem in that the molecular weight of the styrene resin was significantly reduced. [Object of the Invention] The object of the present invention is to provide a method for producing a flame-retardant styrene foam resin that has a well-balanced property without impairing the original properties of the styrene foam resin, particularly heat resistance and mechanical properties. It's about doing. [Structure of the Invention] The present invention provides an organic solvent solution containing (A) 0.1 to 10 parts by weight of a compound represented by the following general formula (), or (B) a compound represented by the following general formula (), based on 100 parts by weight of a styrenic resin. A flame-retardant expanded styrenic resin characterized by adding an organic solvent solution containing a total of 0.1 to 10 parts by weight of a compound of the following formula () and a compound of the following general formula (), and (C) a foaming agent, and foaming with heating. This is a manufacturing method.

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[However, in the above formulas () and (), X represents a chlorine atom or a bromine atom, and all Xs do not necessarily have to be the same atom; Y is an alkylidene having 1 to 6 carbon atoms. group, cycloalkylidene group having 6 to 12 carbon atoms, -O-,-
represents CO-, -S-, _-SO2 or a direct bond; ^R1 and ^R2 each independently represent a hydrogen atom or a methyl group; m and n each independently represent an integer from 1 to 4; ] The styrenic resin used in the present invention refers to a resin containing styrene and/or methylstyrene as a raw monomer component, such as polystyrene, polymethylstyrene, AS resin, ABS
Examples include (graft) copolymers such as resins, AAS resins, AES resins, MBS resins, and high impact polystyrene resins. Representative examples of the compounds represented by the above general formula () used in the present invention include, for example:

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Examples include [C]. Representative examples of compounds represented by the general formula () used in the present invention include, for example:

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〔Effect of the invention〕

The compound of general formula () and the compound of general formula () used in the present invention are used as an organic solvent solution, so in extrusion foaming, the extrusion temperature can be lowered, so the styrene resin used in extrusion The deterioration of the compound, especially the decrease in molecular weight, can be suppressed, and the compound can be easily permeated and absorbed even in bead foaming. Surprisingly, almost no solvent used remains in the foamed resin. Further, since the reaction product liquid in the production of compounds () and () is used only after being concentrated or diluted, a cost reduction effect can be obtained. Since it exhibits the above-mentioned excellent effects, the flame-retardant expanded styrene resin produced by the method of the present invention can be widely used as construction materials, electrical equipment materials, interior goods, and other miscellaneous goods. The present invention will be explained in detail with reference to Examples below. The combustion test was determined according to JIS-A-9551.
Also, the specific viscosity is for a 10g/toluene solution.
It was determined by measuring at 30°C. Examples 1, 2, 3 Comparative Examples 1, 2, 3 To 100 kg of polystyrene resin (Tenka Styrol GP-1-301 manufactured by Denki Kagaku Co., Ltd.), while pressurizing methyl chloride as a foaming material, the amount of solution listed in Table 1 was added. Add from the pent part of the extruder and extrude at 220℃,
The density, specific viscosity, and flame retardance shown in Table 2 were obtained. Comparative example 3
The above method was followed except that the polystyrene resin and flame retardant were mixed and extruded.

【table】

[Table] Example 4 Into an autoclave with a capacity of 10, 3 kg of water, 1 kg of polystyrene beads, and 30 g of the solution of Example 2 were charged.
After heating to 100°C, butane gas was pressurized until the pressure reached about 10 kg/cm ² . After about 6 hours, the foamable beads were taken out by cooling and depressurized, washed with water, and then dried at room temperature. Furthermore, 96% (14.4g) of the charged flame retardant was impregnated or attached to the beads. The obtained expandable beads were foam-molded in a conventional manner to obtain a polystyrene foam having a density of 0.035 g/cm ³ . A test piece of 200 x 25 x 10 mm was cut out from this foam and subjected to a combustion test according to JIS-A-9551. As a result, the combustion time was 0.9 seconds and the test piece passed the test.

Claims (1)

[Scope of Claims] 1. (A) An organic solvent solution containing 0.1 to 10 parts by weight of a compound represented by the following general formula (), or (B) a compound represented by the following general formula (), based on 100 parts by weight of a styrene resin. Production of a flame-retardant expanded styrenic resin characterized by adding an organic solvent solution containing a total of 0.1 to 10 parts by weight of a compound of the following general formula () and (C) a foaming agent, and foaming with heating. Method. [Chemical formula] [Chemical formula] [However, in the above formulas () and (), X represents a chlorine atom or a bromine atom, and all Xs do not necessarily have to be the same atom; Y has 1 to 1 carbon atoms. 6 alkylidene group, cycloalkylidene group having 6 to 12 carbon atoms, -O-,-
represents CO-, -S-, _-SO2- or a direct bond; ^R1 and ^R2 each independently represent a hydrogen atom or a methyl group; m and n each independently represent an integer from 1 to 4; ]