JPH05140389A - Flame retardant styrenic resin composition excellent in heat and light resistance - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a styrenic resin, a specific bromine compound, a pentaerythritol type diphosphite compound and an organotin compound, causing hardly any thermal deterioration with no fear of corroding metallic molds, capable of molding hot liners and useful as molded products, etc. CONSTITUTION:The objective composition is composed of (A) 100 pts.wt. styrenic resin, (B) preferably 0.5-25 pts.wt. compound expressed by formula I or II (X is Br, H or 1-3C haloalkyl; B is 2-4C haloalkyl; A is formula III or SO2) and (C) preferably 0.001-3.0 pts.wt. pentaerythrtiol type diphosphite compound such as distearylpentaerythritol diphosphite and/or organotin compound such as di-n-butyltin maleate polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant styrene resin composition having excellent heat resistance and light resistance.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining a flame-retardant styrene resin composition having excellent heat resistance, for example, Japanese Patent Publication No.
As described in Japanese Patent Publication No. 43060 and Japanese Patent Publication No. 62-34784, there are known methods using heat-stabilized hexabromocyclododecane.

However, in such a conventional flame-retardant method for a styrene-based resin, the heat resistance of the flame-retardant itself is increased as the resin is modified.
Light resistance is poor, heat-stabilized molding resin is colored, so it can not be used for molded products for light color applications, not only the mold corrodes due to hydrogen bromide generated due to thermal decomposition of the flame retardant itself during molding, In the molding method by hot liner method, which is a recent tendency that the physical properties of resin, light resistance and flame retardance are lowered, high temperature residence time is long, and it is difficult for molding processing manufacturers to use because precise control of molding temperature is required. Further, there is a problem that it is difficult to reuse the molding waste.

[0004]

In view of the above circumstances, the present invention provides a compound represented by the general formula (a) or (b):
An object of the present invention is to provide a flame-retardant styrenic resin composition that solves the above-mentioned problems in the prior art by using a pentaerythritol type diphosphite compound and / or an organotin compound in combination.

[0005]

The present invention includes (1) a styrene resin, (2) a compound represented by the following general formula (a) or (b), (3) a pentaerythritol type diphosphite compound, and It is a flame-retardant styrene-based resin composition having excellent heat resistance and light resistance, which is characterized by comprising an organic tin compound.

[0006]

[Chemical 3]

[0007]

[Chemical 4]

The styrene-based resin used in the present invention is generally called a styrene-based resin such as a polymer of styrene monomer and α-methylstyrene / styrene monomer copolymer. The resin may contain a small amount of a third component such as butadiene, methyl methacrylate, acrylonitrile, brominated styrene, maleic anhydride, and itaconic acid.

The compound represented by the general formula (a) to be blended with the styrene resin is, for example, 2,4,6-tribromophenoxy-2,3-dibromo-2-methylpropyl, 2,4,6-tri Bromophenoxy bromochloropropyl, 2,4,6-tribromophenoxy-2,3-
Dibromopropyl, pentabromophenoxy-2,3-
Dibromopropyl, pentabromophenoxy-2,3-
Dibromo-2-methylpropyl, dibromocresyl-
2,3-dibromopropyl and the like.

Further, the compound represented by the general formula (b) is
For example, bis (dibromophenyldibromopropyl) propane, bis (dibromophenyldibromomethylpropyl) propane, bis (dibromophenyldibromopropyl) sulfone, bis (dibromophenyldibromomethylpropyl) sulfone, and the like.

Next, the pentaerythritol type diphosphite compound used in combination with the compound represented by the general formula (a) or (b) is, for example, distearyl pentaerythritol diphosphite or bis (2,4-di-t-butylphenyl). ) -Pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl)-
Examples thereof include pentaerythritol diphosphite and dinonylphenyl pentaerythritol diphosphite.

Further, as the organic tin compound, for example, di-n-octyl maleate polymer, di n-butyl-tin maleate polymer, dibutyl tin-3-mercaptopropionate, di-n-octyl tin-3-mercaptopropionic acid. Salt, dibutyltin mercaptoacetate, diethylene glycol bis (butyltin thioacetate), dibutyltin sulfide, dioctyltin sulfide, dibutyltin dioctyl mercaptide, dimethyltin bis (ethylene glycol monothioglycolate), dibutyltin bis (ethylene glycol monothioglycolate) ) Etc.

The compound of the present invention represented by the general formula (a) or (b) and the pentaerythritol type diphosphite compound and / or the organotin compound may be compounded by any method, but usually, Styrene resin 100
0.5 to 25 parts by weight of the compound represented by the general formula (a) or (b), and 0.1 to 0.5 parts by weight of the pentaerythritol type diphosphite compound and / or the organotin compound.
It is preferable to mix them in a ratio of 001 to 3.0 parts by weight.

The blending method of the pentaerythritol-type diphosphite compound and / or the organotin compound is preferably blended with the compound represented by the general formula (a) or (b) of the present invention and blended with the resin. .. Further, in the present invention, antimony trioxide may be blended if necessary.

The molding temperature of the refractory styrene resin composition of the present invention is suitably in the range of 200 to 250 ° C.
If the temperature is below 200 ° C, the fluidity of the resin will decrease, and at 250 ° C
When it becomes above, coloring and decomposition may occur.

[0016]

The present invention uses a compound represented by the general formula (a) or (b) as a component imparting flame retardancy and a pentaerythritol type diphosphite compound and / or an organotin compound as a component imparting heat resistance. By using it, it becomes possible to perform hot liner molding which could not be used in the prior art, and it is possible to provide a flame-retardant styrene resin composition having excellent heat resistance and light resistance.

[0017]

EXAMPLES The embodiments and effects of the present invention will be described below with reference to examples, but the examples are merely for the purpose of illustration and are not intended to limit or limit the inventive idea. In addition,
In the examples, parts and% are based on weight.

Example. A predetermined amount of the compound represented by the general formula (a) or (b), a pentaerythritol type diphosphite compound and / or an organic tin compound are mixed for 3 minutes with a vertical mixer, and a predetermined amount of HI-polystyrene resin ( Ethylene; manufactured by Nippon Steel Chemical Industry Co., Ltd. was added and mixed, and after kneading with an extruder having an inner diameter of 20 m / mφ adjusted to 220 ° C., the mixture was extruded from a die having a caliber of 3 m / mφ. The obtained strand was cut into pellets.

Further, after being allowed to stay for 20 minutes in an injection molding machine whose temperature was adjusted to 230 ° C., injection molding was restarted, a test piece after the stay was taken, and a change in color tone with the test piece before the stay was measured. The results are shown in Table 1.

[0020]

[Table 1]

However, the items in Table 1 have the following meanings. TBP-A; 2,4,6-tribromophenoxy-2,
3-dibromo-2-methylpropyl, TBP-B; 2,4,6-tribromophenoxybromochloropropyl, TBA-D; bis (dibromophenoldibromopropyl) propane, HBCD; hexabromocyclododecane,

(A) Bis (2,6-di-t-butyl-)
4-methylphenyl) -pentaerythritol diphosphite, (b); dibutyltin sulfide, (c); dibutyltin-3-mercaptopropionate, (d); di-n-butyltin maleate polymer,

Heat resistance: After being retained in an injection molding machine at 230 ° C. for 20 minutes, the change in color tone was measured by a color difference meter. Difficulty: Performed according to UL-94 (1/8 inch). Heat distortion temperature and impact strength: Measured according to JIS-6871. Light resistance: The obtained test piece was fed with a fedometer (63
After irradiation for 24 hours, the change in color tone was measured with a color difference meter.

[0024]

Industrial Applicability As described and demonstrated above, the present invention is a heat-resistant and light-resistant molding with little thermal deterioration at a general working temperature such as injection molding or rolling of styrene resin without fear of mold corrosion. It is possible to provide a refractory styrene resin composition that gives a product.

Claims (1)

[Claims] 1. A composition comprising (1) a styrene resin, (2) a compound represented by the following general formula (a) or (b), and (3) a pentaerythritol-type diphosphite compound and / or an organotin compound. A flame-retardant styrene-based resin composition having excellent heat resistance and light resistance, characterized by: [Chemical 1] [Chemical 2]