JPH1143511A - Brominated styrene oligomer, its production and flame-retardant resin composition compounded with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject oligomer readily meltable and dispersible into resins such as a general-purpose polypropylene and an impact-resistant polystyrene, capable of developing high flame-retardance, heat resistance and processability without lowering mechanical properties of resin and without changing the color of resin, by possessing specific physical properties. SOLUTION: This oligomer shows physical properties of 300-1,200 weight- average molecular weight calculated as polystyrene, 40-70 wt.% of bromine content, 50-150 deg.C softening point as light yellow powder, heat stability measured by a thermobalance of 5% reduction at >=300 deg.C and 50% reduction at >=350 deg.C. The oligomer is produced by brominating a styrene oligomer having 300-1,200 weight-average molecular weight obtained by cationic polymerization with a brominating agent such as bromine chloride in a solvent such as dichloromethane inert to the reaction in the presence of a catalyst such as antimony trichloride. The oligomer is meltable and dispersible into an acrylonitrile-styrene-butadiene copolymer resin, a polybutylene terephthalate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel brominated styrene oligomer having excellent quality, a method for producing the same, and a flame-retardant resin composition containing the same. The brominated styrene oligomer of the present invention is a compound useful for flame retardancy of a synthetic resin, and can be used for flame retardation of a resin frequently used in various electric appliances and the like.

[0002]

2. Description of the Related Art With respect to flame retardancy of synthetic resins, various bromine-based flame retardants, phosphate ester-based flame retardants, and inorganic flame retardants are used for various resins, and they are used properly depending on the application. . Representative flame retardants are decabromodiphenyl oxide, tetrabromobisphenol-A,
TBA-epoxy oligomers, brominated polystyrene, triphenyl phosphate, magnesium hydroxide, aluminum hydroxide and the like.

As a brominated flame retardant having a styrene unit, in addition to the above-mentioned brominated polystyrene, a brominated styrene oligomer having a weight average molecular weight in terms of polystyrene of about 1400 is commercially available.

[0004]

The conventional brominated polystyrene is mainly composed of nylon, polyethylene terephthalate,
It is used for engineering plastics represented by polybutylene terephthalate, but because of its high weight average molecular weight of about 200,000, high impact polystyrene (hereinafter HI)
When mixed with general-purpose resins such as PS), achloronitrile-styrene-butadiene copolymer resin (hereinafter abbreviated as ABS), and polypropylene (hereinafter abbreviated as PP), there is a problem that the properties of the compounded resin are significantly reduced. .

On the other hand, commercially available styrene oligomers are
Although it can be applied to general-purpose resins such as HIPS, ABS and PP, there is a problem that heat resistance is poor and the color tone of the compounded resin is brown.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on high-quality brominated styrene oligomers, and have found that brominated styrene oligomers obtained by brominating styrene oligomers obtained by cationic polymerization are used as raw materials. Have excellent heat resistance, and have a compounded resin physical property superior to that of a conventional product by setting the weight average molecular weight of the raw material to 200 to 1,000, and have completed the present invention.

That is, the present invention is a pale yellow powder having a weight average molecular weight in terms of heavy polystyrene of 300 to 1200, a bromine content of 40 to 70% by weight, and a softening point of 50 to 150 ° C. Styrene oligomer characterized in that its thermal stability by 5% shows a physical property of 300 ° C. or more in a 5% decrease and 350 ° C. or more in a 50% decrease, a method for producing the same, and a flame-retardant resin composition comprising the same Things.

Hereinafter, the present invention will be described in detail.

The brominated styrene oligomer of the present invention has a weight average molecular weight of 300 to 1200 in terms of heavy polystyrene.
, A bromine content of 40 to 70% by weight and a softening point of 50 to 1
It is a pale yellow powder in the range of 50 ° C., and the thermal stability measured by thermobalance is 5% decrease at 300 ° C. or more and 50% decrease at 35%.
Shows physical properties of 0 ° C or higher.

The raw material styrene oligomer used in the present invention is obtained by reacting a styrene monomer in a solvent inert to the reaction in the presence of a cationic polymerization catalyst such as aluminum chloride, iron trichloride, antimony trichloride, trifluoroborane etherate or the like.
Oligomers obtained by the reaction and having a weight average molecular weight of 300 to 1200 can be applied to the present invention.

The brominated styrene oligomer of the present invention can be obtained by reacting a raw material styrene oligomer with a bromination reagent in a solvent inert to the reaction in the presence of a catalyst.

Specific examples of the catalyst applicable to the present invention include aluminum chloride, aluminum bromide, ferric chloride, ferric bromide, titanium tetrachloride, titanium trichloride, antimony pentachloride, and antimony trichloride. And Lewis acid catalysts such as antimony tribromide, tin chloride and trifluoroborane etherate. These catalysts are selected according to the desired number of nuclear brominations. These catalysts may be used alone or in combination of two or more without any problem.

The catalyst can be used in any amount with respect to the unit styrene unit of the starting oligomer used in the reaction, and specifically, in the range of 0.01 to 100 mol / mol%. Range. Use of too small a quantity may be slow or deactivated by impurities from the raw materials and solvents, while use of too much is not economical. Therefore, it is preferably in the range of 0.1 mol / mol% to 40 mol / mol%.

The brominating agents applicable to the present invention include:
Specifically, they are bromine and bromine chloride, and they are selectively used or mixed depending on the desired number of nuclear brominations, the catalyst to be used, and the target quality of the obtained target product. When bromine chloride is used, chlorination occurs as a side reaction, and about 0.1 to 5% by weight of chlorine is contained in the target product in a state of being bonded to the aromatic ring. In order to obtain a whiter target product, it is preferable to use bromine chloride.

The amount of the brominating agent used depends on the number of nuclear brominations per unit unit of the desired starting oligomer. Usually, an equimolar amount or more and an equimolar amount or more and a molar amount or less with respect to the intended number of nuclear brominations are used. Determine the amount to be used depending on the type and reaction conditions.

As the solvent used in the reaction, any solvent can be used as long as it is inert to the bromination reagent and the catalyst. Specifically, dichloromethane, dibromomethane, chloroform, bromoform, tetrachloride carbon,
Examples thereof include 1,2-dichloroethane and 1,1,2-trichloroethane.

The solvent can be used in any ratio with respect to the starting oligomer used in the reaction.
If the amount is less than 1 part by weight, the viscosity of the reaction solution after the completion of the reaction becomes high, which is not preferable. If the amount is more than 100 parts by weight, it is not economical. Therefore, it is preferably at least 1.2 times by weight 80
It is in the range of the weight amount.

The reaction temperature varies depending on the bromination reagent, the catalyst and the desired degree of nuclear bromination, but is usually in the range of 0 ° C. to 60 ° C. when bromine is used. -30 ° C ~ when combined with bromine chloride
Since the reaction is exothermic and involves the generation of hydrogen halide gas during the dropping time of the bromination reagent carried out in the range of 20 ° C., the reaction temperature can be controlled and the generated hydrogen halide gas is out of the system. There is no particular limitation as long as the conditions can be captured by.

After completion of the addition of the brominating agent, post-treatment may be performed immediately, or aging may be performed at a predetermined temperature for 1 to 8 hours.

After completion of the reaction, excess brominating agent is harmed by adding a reducing agent such as hydrazine or sodium bisulfite, and then crystallization is performed by washing with water or adding to a poor solvent such as methanol or hot water. The resulting product is further filtered and dried to obtain the desired brominated styrene oligomer.

The brominated styrene oligomer of the present invention exhibits high flame-retardant properties and blended resin physical properties by being blended with a thermosetting resin or a thermoplastic resin without deteriorating the mechanical performance and color tone of the resin.

Specific examples of the resin to which the brominated styrene oligomer of the present invention can be blended include thermosetting resins such as phenol resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane, alkyd resin, epoxy resin and the like. Resin, low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polystyrene, high-impact polystyrene, expanded polystyrene, acrylonitrile-styrene copolymer, achloronitrile-styrene-butadiene copolymer (hereinafter ABS) Abbreviation), polypropylene, petroleum resin, polymethyl methacrylate,
Polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, thermoplastic resins such as polyphenylene ether, and the like. Further, polycarbonate-ABS obtained by mixing two or more kinds of thermoplastic resins,
Polymer alloys represented by polyphenylene ether-polystyrene and the like can also be exemplified. Among them, low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polystyrene, high-impact polystyrene, expanded polystyrene, acrylonitrile-styrene copolymer, achloronitrile-styrene-butadiene copolymer (ABS) ), Polypropylene, petroleum resin, polymethyl methacrylate, polyamide, polycarbonate,
Suitable resins are thermoplastic resins such as polyethylene terephthalate, polybutylene terephthalate and polyphenylene ether, and polymer alloys represented by polycarbonate-ABS, polyphenylene ether-polystyrene and the like in which two or more thermoplastic resins are mixed.

The amount of the brominated styrene oligomer of the present invention to be mixed with the resin depends on the type of the resin to be mixed and the intended flame retardancy, and is not particularly limited.
Usually, 5 to 50 parts by weight are blended with respect to 100 parts by weight of the resin.

In blending the brominated styrene oligomer of the present invention with a resin, a flame retardant aid such as antimony trioxide and sodium antimonate may be added. In this case, 100 parts by weight of the brominated styrene oligomer of the present invention is used. Is usually added in an amount of 5 to 80 parts by weight. If necessary, a benzotriazole-based ultraviolet absorber, 2,2,6,6-
A light stabilizer such as a tetramethylpiperidine derivative, a hindered phenol-based antioxidant and the like may be added. In this case, usually 0.05 to 5 parts by weight based on 100 parts by weight of the flame-retardant resin composition of the present invention. Parts are added. In addition to these, if necessary, an inorganic filler such as an antistatic agent, talc, or glass fiber may be added.

As a method of blending the brominated styrene oligomer of the present invention with a resin, when blending with a thermosetting resin, for example, the brominated styrene oligomer derivative of the present invention is dispersed in a resin material in advance and then cured. In the case of mixing with a thermoplastic resin, for example, a necessary compounding agent may be mixed using a conical blender or a tumbler mixer, and pelletized using a twin-screw extruder or the like. The processing method of the flame-retardant resin composition obtained by these methods,
There is no particular limitation, and for example, extrusion molding, injection molding, or the like can be performed to obtain a desired molded product.

[0026]

According to the present invention, the brominated styrene oligomer is
Because the softening point is 200 ° C or less, general-purpose polypropylene,
High impact polystyrene, acrylonitrile-styrene-
Butadiene copolymer resin, polybutylene terephthalate,
It melts and disperses in resins such as polyamide, polyethylene terephthalate, and polycarbonate, and exhibits high flame retardancy and high processability without deteriorating the mechanical properties of the resin.
Further, compared to conventional brominated styrene oligomers, it has excellent heat resistance, eliminates the problem of resin discoloration during molding, and can be applied to coloring of blended resins.

[0027]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 20 equipped with a stirrer and a dropping funnel with a cooling jacket
A 5-liter round-bottomed separable flask was charged with 700 g of a styrene oligomer having a weight average molecular weight of 900 obtained by cationic polymerization, 55.0 g of antimony trichloride, and 8000 g of dichloromethane, and cooled to 0 ° C. on an ice bath. did.

Then, at 0 ° C., 1700 g of bromine and 6
A dichloromethane solution of bromine chloride prepared from 90 g and 3,500 g of dichloromethane was charged into a dropping funnel equipped with a cooling jacket in four portions, dropped over 6 hours, and aged at the same temperature for 6 hours.

After completion of the reaction, 1 liter of a 20% by weight aqueous solution of hydrazine was added to the reaction solution, and after removing excess bromine chloride, the solution was washed three times with 5 liters of water and separated. The obtained reaction solution was divided into four times, and crystallized by adding to 6 liters of stirred methanol (24 liters in total).
Filtration and drying under reduced pressure of 1 mmHg at 120 ° C. for 4 hours give the desired brominated styrene oligomer 1990
g of a pale yellow powder was obtained.

The results of elemental analysis, softening point, nuclear magnetic resonance spectrum, infrared absorption spectrum, gel permeation chromatograph, and thermobalance measurement of the obtained brominated styrene oligomer are shown.

Elemental Analysis Results CHBrCl Measured Value (% by Weight) 30.6 1.5 67.5 0.4 Softening Point: 97-129 ° C. Nuclear Magnetic Resonance Spectrum (CDCl ₃ , ppm): δ 1.
0-1.8 (m, 2H), 2.2-2.7 (bs, 1.
0H), 6.5-7.8 (m, 2.3H) Gel permeation chromatograph (THF): MW
= 1038, MN = 308, MW / MN = 3.37 Thermobalance (10 ° C / min): 5% reduction (325 ° C), 1
0% reduction (344 ° C), 50% reduction (382 ° C), 90
% Reduction (515 ° C).

Example 2 Using the same reactor as in Example 1, the weight average molecular weight was 57
The same operation as in Example 1 was carried out except that the raw material obtained by the cationic polymerization of Example 1 was used to obtain 1760 g of a powder of a brominated styrene oligomer. The analysis results are shown below in the same manner as in Example 1.

Elemental analysis results: CHBrCl measured value (% by weight) 30.8 1.3 67.0 0.7 Softening point: 78-112 ° C Nuclear magnetic resonance spectrum (CDCl ₃ , ppm): δ 1.
0-1.8 (m, 2H), 2.2-2.7 (bs,
1.0H), 6.5-7.8 (m, 2.4H) Thermal balance (10 ° C / min): 5% reduction (308 ° C), 1
0% reduction (342 ° C), 50% reduction (363 ° C), 90
% Reduction (496 ° C).

Examples 3 to 4 The brominated styrene oligomer prepared in Example 1 or Example 2 was added to 100 parts by weight of high-impact polystyrene (hereinafter abbreviated as HIPS, HT-88 manufactured by Mitsubishi Chemical) for 20 parts by weight. Parts by weight, 6.7 parts by weight of antimony trioxide, and using a twin-screw extruder (L / D: 25), a melting temperature of 205 to 215 ° C.
Injection molding was performed at a mold temperature of 45 ° C.

Using the obtained sample, a flammability test, workability (flowability), impact resistance, tensile test and bending test, and color difference measurement were carried out by the following methods.

<Evaluation method of flammability test> For a test piece prepared from a sample obtained by injection molding, the oxygen index is based on JIS-K-7201, and the UL flammability test is UL9.
Each was measured according to the 4V vertical flammability test method.

<Method for Evaluating Processability (Fluidity)> Using the obtained pellets, the melt flow rate (200 ° C. × 5 kg) was measured in accordance with JIS-K-6760.

<Impact Resistance> A test piece was prepared from a sample obtained by injection molding, and the Izod impact value was measured in accordance with ASTM-D-256.

<Tensile test> From a sample obtained by injection molding, a test piece was punched out with a No. 3 dumbbell and measured at a pulling speed of 200 mm / min.

<Bending Test> A test piece was prepared from a sample obtained by injection molding and measured in accordance with JIS-K-7203.

<Measurement of Color Difference> A test piece of 50 mm × 50 mm × 2 mm was prepared from a sample obtained by injection molding, and the color difference from a standard white plate was calculated by the following equation using a color difference meter.

W = {(100−L) ² + a ² + b ² } ^1/2 (where L, a, and b represent measured values of the test piece) These results are also shown in Table 1.

[0044]

[Table 1]

Comparative Example 1 Using a commercially available brominated styrene oligomer (Pyrocheck LM manufactured by Ferro), H was used in the same manner as in Examples 3 and 4.
It was blended with IPS and an evaluation test was conducted. The results are shown in Table 1. Table 1 also shows various evaluation results of HIPS alone.

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Claims (4)

[Claims] 1. A polystyrene-equivalent weight average molecular weight of 3
A bromine content of 40 to 70% by weight in the range of 00 to 1200;
It is a pale yellow powder having a softening point in the range of 50 to 150 ° C.
A brominated styrene oligomer characterized in that 0% decrease shows physical properties of 350 ° C. or more. 2. The brominated styrene oligomer according to claim 1, wherein a styrene oligomer having a weight average molecular weight in the range of 300 to 1200 obtained by cationic polymerization is brominated with a bromination agent in the presence of a catalyst. Production method. 3. A flame-retardant resin composition comprising the resin and the brominated styrene oligomer according to claim 1. 4. The flame-retardant resin composition according to claim 3, wherein 5 to 50 parts by weight of the brominated styrene oligomer according to claim 1 is mixed with 100 parts by weight of the resin.