JPH11217445A - Stabilization of physical properties of flame retardant styrene type resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method to stabilize the physical properties of a flame retardant styrene type resin which enables not only improved physical properties of the styrene type resin but also high productivity and improved physical properties in the course of production as a result of its improved stability at melt extrusion. SOLUTION: With (A) a styrene type resin melt-blended is (B) a flame retordant which does not melt at 300 deg.C or lower, at a temp. of 150-300 deg.C after dispersing it with (C) a dispersion agent at a temp. of 0-100 deg.C. (B) is a flame retardant selected from the group consisting of antimony oxide, a fluorinated resin and a brominated flame retardant and (C) is a higher aliph. amide and/or a liq. paraffin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for stabilizing physical properties of a flame-retardant styrene resin. More specifically, not only the physical properties of the styrene-based resin are improved, but also the stability of the melt-extrusion is improved. About the method.

[0002]

2. Description of the Related Art Styrene-based resins are excellent in impact resistance in addition to excellent moldability.
Although it is used in various fields such as home electric appliance parts and OA equipment parts, its use is limited due to the flammability of styrene resins.

[0003] As a method of making a styrene resin flame-retardant,
It is known to add halogen-based, phosphorus-based, and inorganic-based flame retardants to styrene-based resins, thereby achieving some degree of flame retardancy. However, when the flame retardant is a powder, it acts as a foreign substance in the molded product, significantly lowering the impact strength. However, there is a problem that the miscibility and dispersibility with the styrene-based resin are poor, and the flame retardant is classified and stable flame retardancy is not exhibited.
From such a background, a flame-retardant styrene-based resin that maintains impact strength and has excellent productivity and stability of physical properties has been demanded.

[0004] As a technique for improving the handleability of powder compounds, a masterbatch technique for powder compounds is known. For example, a method for producing a colorant, a dispersing aid, a resin colorant capable of softening and melting the resin (Japanese Patent Application Laid-Open No. 9-241390), or a pigment masterbatch in which polyolefin wax and a processed pigment are dispersed in crystalline polypropylene (Patent No. 26th
No. 54979), the use of a masterbatch improves the classification from pelletized styrene-based resin, but the dispersibility is insufficient, the impact strength is poor, and industrial use is restricted.

[0005]

SUMMARY OF THE INVENTION In view of the above situation, the present invention has no problems as described above, that is, as a result of improving the handleability of a powdery flame retardant and the stability of melt extrusion. It is an object of the present invention to provide a method for stabilizing physical properties of a flame-retardant styrene-based resin which enables high productivity, excellent physical properties, and stable quality with little variation in physical properties during production.

[0006]

Means for Solving the Problems As a result of intensive studies on a method for stabilizing the physical properties of a flame-retardant styrenic resin, the present inventor has treated a styrene-based resin with a specific flame retardant and a dispersant under specific conditions. As a result, the present inventors have surprisingly found that the physical properties and the stability of the physical properties at the time of production are dramatically improved, and have reached the present invention.

That is, the present invention provides (1) at least (B)
At least a portion of the flame retardant that does not melt below 300 ° C.
(C) After treatment with a dispersant at 0 to 100 ° C.,
(A) a method for stabilizing the physical properties of a flame-retardant styrene resin, which is characterized by being melt-kneaded together with (A) a styrene resin at 300 ° C .;
A flame retardant that does not melt at 0 ° C. or less is added with a dispersant (C) from 0 to 1
A method for stabilizing the physical properties of a flame-retardant styrenic resin, which is characterized by being melted and kneaded at 150 to 300 ° C. after being dispersed at 00 ° C., especially (B) selected from antimony oxide, fluorine resin and bromine-based flame retardant. An object of the present invention is to provide a method for stabilizing the physical properties of a flame-retardant styrene resin in which the flame retardant and / or (C) is a higher fatty acid amide or liquid paraffin.

Hereinafter, the present invention will be described in detail.

The present invention relates to (A) a styrene resin, (B)
The present invention relates to a method for stabilizing physical properties of a resin composition comprising a specific flame retardant and a dispersant (C).

The above (A) is a main component of the molding resin composition and plays a role of maintaining the strength of the molded article, and (B) is a component for imparting flame retardancy to the styrene resin. C)
Is a component for improving the dispersibility of (B) in (A).

In the method of the present invention, first, (A) and (B)
(B) and (C) or (A), (B), (C) or (B), (C) and other resins or additives before melt mixing (C) It is important to carry out dispersion treatment at 100 ° C. The surface is coated by treating the flame retardant (B) that does not melt at 300 ° C. or less with (C),
In (A), it was found that the dispersibility was improved and excellent impact strength was exhibited. Furthermore, it has been found that the method of the present invention can prevent the classification of the flame retardant in (A), and as a result, it is possible to improve the productivity and the stability of physical properties during production. Completed the invention.

Hereinafter, each component of the present invention will be described in detail.

The styrene resin (A) used in the present invention is a rubber-modified styrene resin and / or a non-rubber-modified styrene resin.

Such a rubber-modified styrenic resin is a polymer obtained by dispersing a rubbery polymer in the form of particles in a matrix composed of a vinyl aromatic polymer. It can be obtained by adding a group IV vinyl monomer and, if necessary, a vinyl monomer copolymerizable therewith, and subjecting the monomer mixture to a known bulk polymerization, bulk suspension polymerization, solution polymerization, or emulsion polymerization.

Examples of such resins include impact-resistant polystyrene, ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acryl rubber-styrene copolymer), and AES resin (acrylonitrile-ethylene copolymer). Propylene rubber-styrene copolymer).

Here, the rubbery polymer needs to have a glass transition temperature (Tg) of -30 ° C. or less,
If the temperature exceeds -30 ° C, the impact resistance decreases.

Examples of such rubbery polymers include diene rubbers such as polybutadiene, poly (styrene-butadiene) and poly (acrylonitrile-butadiene), and saturated rubbers obtained by hydrogenating the diene rubbers, isoprene rubbers, chloroprene rubbers. , An acrylic rubber such as polybutyl acrylate, and an ethylene-propylene-diene monomer terpolymer (EPDM). A diene rubber is particularly preferred.

The aromatic vinyl monomer as an essential component in the graft-polymerizable monomer mixture to be polymerized in the presence of the rubbery polymer is, for example, styrene, α-methylstyrene, paramethylstyrene, p-methylstyrene, -Chlorostyrene, p-bromostyrene, 2,4,5-tribromostyrene and the like, and styrene is most preferred, but the above aromatic vinyl monomer may be copolymerized mainly with styrene.

If necessary, one or more monomer components copolymerizable with the aromatic vinyl monomer can be introduced as components of the rubber-modified styrene resin. When it is necessary to increase oil resistance, unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile can be used.

If it is necessary to lower the melt viscosity during blending, an acrylate comprising an alkyl group having 1 to 8 carbon atoms can be used. Further, when it is necessary to further increase the heat resistance of the resin composition, α-methylstyrene, acrylic acid, methacrylic acid,
Monomers such as maleic anhydride and N-substituted maleimide may be copolymerized. The content of the vinyl monomer copolymerizable with the vinyl aromatic monomer in the monomer mixture is from 0 to 40.
% By weight.

In the present invention, the rubbery polymer in the rubber-modified styrenic resin is preferably 5 to 80% by weight,
Particularly preferably, it is in the range of 10 to 50% by weight, and the graft-polymerizable monomer mixture is in the range of preferably 95 to 20% by weight, more preferably 90 to 50% by weight. Within this range, the balance between impact resistance and rigidity of the target resin composition is improved. Further, the rubber particle diameter of the styrene-based polymer is preferably from 0.1 to 5.0 μm, particularly preferably from 0.2 to 3.0 μm.
0 μm is preferred. Within the above range, impact resistance is particularly improved.

In the present invention, the reduced viscosity ηsp / c is a measure of the molecular weight of the rubber-modified styrenic resin used.
(0.5 g / dl, 30 ° C. measurement: toluene solution when the matrix resin is polystyrene, methyl ethyl ketone when the matrix resin is an unsaturated nitrile-aromatic vinyl copolymer): 0.30 to 0.80 dl / g And more preferably in the range of 0.40 to 0.60 dl / g. Means for satisfying the above requirements regarding the reduced viscosity ηsp / c of the rubber-modified styrenic resin include adjustment of the polymerization initiator amount, polymerization temperature, and chain transfer agent amount.

In the present invention, (B) the flame retardant is 300
There is no particular limitation as long as it is a flame retardant that does not melt at a temperature of not more than ° C.
For example, halogen-based, phosphorus-based, nitrogen-based or inorganic-based flame retardants or silicone resins, silica, aramid fibers, polyacrylonitrile fibers, and the like.

The halogen-based flame retardant (B) is as follows:
Aromatic halogen compounds, halogenated polycarbonates,
Halogenated aromatic vinyl polymers, halogenated cyanurate resins, halogenated polyphenylene ethers and the like, preferably decabromodiphenyl oxide, brominated bisphenol-based phenoxy resins, brominated bisphenol-based polycarbonate, brominated polystyrene, and brominated cross-linked Polystyrene, brominated polyphenylene oxide, polydibromophenylene oxide, decabromodiphenyl oxide bisphenol condensate,
Halogen-containing phosphoric esters and fluorine-based resins.

As the phosphorus-based flame retardant in the above (B),
Organic phosphorus compounds, red phosphorus, inorganic phosphates and the like can be mentioned.

Examples of the above organic phosphorus compounds include phosphine, phosphine oxide, biphosphine, phosphonium salt, phosphinate, phosphate, phosphite and the like.

In the above (B), red phosphorus, which is one of the phosphorus-based flame retardants, is obtained by preliminarily selecting the surface of aluminum hydroxide, magnesium hydroxide, zinc hydroxide or titanium hydroxide in addition to general red phosphorus. Coated with a metal hydroxide coating, coated with a coating composed of a metal hydroxide selected from aluminum hydroxide, magnesium hydroxide, zinc hydroxide, and titanium hydroxide, and a thermosetting resin , Aluminum hydroxide, magnesium hydroxide,
Examples thereof include those obtained by double-coating a thermosetting resin film on a metal hydroxide film selected from zinc hydroxide and titanium hydroxide.

In the above (B), one of the inorganic phosphates of the phosphorus-based flame retardant is typically ammonium polyphosphate.

One of the triazine skeleton-containing compounds of the nitrogen-based flame retardant in the above (B) is melamine, the following formula (1)
, Melem represented by the following formula (2), melon (product of deammonification of three to three molecules of melem at 600 ° C. or more), melamine cyanurate represented by the following formula (3), Melamine phosphate represented by the following formula (4), succinoguanamine, adipoguanamine, methylglutaloganamin represented by the following formula (5), melamine resin represented by the following formula (6), and BT represented by the following formula (7) Resins and the like can be mentioned, and melamine cyanurate is particularly preferable from the viewpoint of low volatility.

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

The inorganic flame retardant (B) includes aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, basic magnesium carbonate, zirconium hydroxide, and tin oxide. Hydrates of inorganic metal compounds such as hydrates, aluminum oxide, iron oxide, titanium oxide, manganese oxide,
Metal oxides such as magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, tin oxide, antimony oxide, nickel oxide, copper oxide, tungsten oxide, aluminum,
Iron, titanium, manganese, zinc, molybdenum, cobalt,
Metal powder such as bismuth, chromium, nickel, copper, tungsten, tin, antimony, and the like, or zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate, mu calcium, calcium carbonate, barium carbonate, and the like can be given. These may be used alone or in combination of two or more.

The silicone resin (B) is made of SiO
₂ , a silicone resin having a three-dimensional network structure formed by combining structural units of RSiO _3/2 , R ₂ SiO, and R ₃ SiO _1/2 . Here, R represents an alkyl group such as a methyl group, an ethyl group or a propyl group, an aromatic group such as a phenyl group or a benzyl group, or a substituent containing a vinyl group in the above substituent. Here, a silicone resin containing a vinyl group is particularly preferable.

Such a silicone resin is obtained by co-hydrolyzing and polymerizing an organohalosilane corresponding to the above structural unit.

The silica as (B) is amorphous silicon dioxide, particularly preferably silica coated with a hydrocarbon compound, which is obtained by treating the silica surface with a hydrocarbon compound silane coupling agent. The hydrocarbon compound-coated silica contained is preferred.

The aramid fiber as (B) preferably has an average diameter of 1 to 500 μm and an average fiber length of 0.1 to 10 mm. Isophthalamide or polyparaphenylene terephthalamide is converted to an amide polar solvent or sulfuric acid. And solution spinning by a wet or dry method.

The polyacrylonitrile fiber (B) has an average diameter of 1 to 500 μm and an average fiber length of 0.1 to 500 μm.
It is preferably 10 mm, and the polymer is dissolved in a solvent such as dimethylformamide and the like, and dry spinning is performed by dry spinning in an air stream at 400 ° C., or wet spinning is performed by dissolving the polymer in a solvent such as nitric acid and wet spinning in water. It is manufactured by the method.

In the present invention, the amount of (B) added is
(A) 1 to 100 parts by weight, preferably 1 to 50 parts by weight, more preferably 3 to 100 parts by weight with respect to 100 parts by weight.
20 parts by weight, most preferably 5 to 15 parts by weight.

In the present invention, the dispersant used as (C) is an aliphatic hydrocarbon, a higher fatty acid or a metal salt thereof, a higher fatty acid ester, a higher fatty acid amide, a higher fatty alcohol, a metal soap, or an organosiloxane-based dispersant. One or more dispersants selected from wax and the like.

The amount of (C) is preferably 0.1 to 20 parts by weight, more preferably 100 parts by weight of (A).
0.5 to 10 parts by weight, most preferably 1 to 5 parts by weight.

The aliphatic hydrocarbon as (C) is liquid paraffin, natural paraffin, microwax, polyolefin wax, synthetic paraffin, and partial oxides thereof, or fluorides and chlorides.

The higher fatty acid or metal salt thereof as (C) is an unsaturated fatty acid or saturated higher fatty acid such as ricinoleic acid, ricinberidic acid, 9-oxy-12-octadecenoic acid, or a metal salt thereof. . The saturated higher fatty acid has 12 to 42 carbon atoms as the carboxylic acid.
Are preferred. For example, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, montanic acid and the like can be mentioned. Examples of the metal of these metal salts include lithium, sodium, potassium, magnesium, calcium, aluminum, and zinc.
Particularly preferred are zinc stearate, magnesium stearate, calcium stearate, and aluminum stearate.

The higher fatty acid ester as (C) is a monohydric alcohol ester of a fatty acid such as methyl phenylstearate or butyl phenylstearate, or a monohydric alcohol ester of a polybasic acid such as diester stearate of diphenylstearyl phthalate. And sorbitan monolaurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquiolate, sorbitan triolate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate , Sorbitan esters such as polyoxyethylene sorbitan monooleate, monoglyceride stearate,
Fatty acid esters of glycerin monomers such as oleic acid monoglyceride, capric acid monoglyceride, behenic acid monoglyceride, polyglycerin fatty acid esters such as polyglycerin stearate, polyglycerin oleate, polyglycerin laurate, and polyoxyethylene mono Fatty acid esters having a polyalkylene ether unit such as laurate, polyoxyethylene monostearate and polyoxyethylene monooleate; and neopentyl polyol fatty acid esters such as neopentyl polyol distearate.

The higher fatty acid amides as (C) include monoamides of saturated fatty acids such as phenylstearic acid amide, methylolstearic acid amide, methylolbehenic acid amide, coconut oil fatty acid diethanolamide, lauric acid diethanolamide, and coconut oil fatty acid diethanolamide. And N, N′-substituted monoamides such as oleic acid diethanolamide and the like.
Saturated fatty acid bisamides such as (hydroxyphenyl) stearamide, ethylenebis (stearic acid amide), ethylenebis (12-hydroxyphenyl) stearic acid amide, hexamethylenebis (12-hydroxyphenyl) stearic acid amide, and m-xylylenebis (12
-Hydroxyphenyl) stearic acid amide and the like.

The higher aliphatic alcohol as (C) is
Monohydric alcohols such as stearyl alcohol and cetyl alcohol; polyhydric alcohols such as sorbitol and mannitol; and polyoxyethylene dodecylamine and polyoxyethylene octadecylamine; and polyalkylene ethers such as polyoxyethylene allylated ether. Allylated ether having a unit, polyoxyethylene lauryl ether, polyoxyethylene tridodecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene alkyl ether such as polyoxyethylene oleyl ether, polyoxyethylene octyl Phenyl ether, polyoxyethylene alkyl phenyl ether such as polyoxyethylene nonyl phenyl ether,
Polyepichlorohydrin ether, polyoxyethylene bisphenol A ether, polyoxyethylene ethylene glycol, polyoxypropylene bisphenol A
It is a dihydric alcohol having a polyalkylene ether unit such as ether or polyoxyethylene polyoxypropylene glycol ether.

The metal soap as (C) is a metal salt of a higher fatty acid such as the above stearic acid, such as barium, calcium, zinc, aluminum or magnesium.

In the present invention, a thermoplastic resin or a thermoplastic elastomer other than (A) can be blended.
For example, polyphenylene ether resin, polyester resin, polyphenylene sulfide resin, polycarbonate resin, polyolefin resin, polymethacrylate resin, polyacetal resin, polyarylate resin, polysulfone resin, and the like are preferable. As the thermoplastic resin other than (A), polyphenylene ether and aromatic polycarbonate are particularly preferable.

In the present invention, one of the thermoplastic resins other than the above (A), polyphenylene ether (hereinafter abbreviated as PPE), is a homopolymer and / or a copolymer comprising a bonding unit represented by the following formula. .

[0054]

Embedded image

However, R ¹ , R ² , R ³ and R ⁴ are each selected from the group consisting of hydrogen, hydrocarbon and substituted hydrocarbon groups, and may be the same or different.

Specific examples of the PPE include poly (2,6-dimethyl-1,4-phenylene ether),
Copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol are preferred, and poly (2,6-dimethyl-1,4-phenylene ether) is particularly preferred. The method for producing such PPE is not particularly limited. For example, a complex of a cuprous salt and an amine according to the method described in US Pat. No. 3,306,874 is used as a catalyst, and for example, 2,6-xylenol is used. It can be easily produced by oxidative polymerization. In addition, US Pat. No. 3,306,075 and US Pat.
No. 257,357, U.S. Pat. No. 3,257,358.
It can be easily produced by the method described in Japanese Patent Publication No. Sho 52-17880 and Japanese Patent Laid-Open Publication No. Sho 50-51197. Reduced viscosity ηsp of the PPE used in the present invention
/ C (0.5 g / dl, chloroform solution, measured at 30 ° C.) is preferably in the range of 0.20 to 0.70 dl / g, and more preferably in the range of 0.30 to 0.60 dl / g. More preferred. Means for satisfying the above requirement for the reduced viscosity of PPE at 9ηsp / C include the PP
Adjustment of the amount of catalyst in the production of E can be mentioned.

In the present invention, one aromatic polycarbonate of the thermoplastic resin other than (A) can be selected from aromatic homopolycarbonate and aromatic copolycarbonate. The production method includes a phosgene method in which phosgene is blown into a bifunctional phenolic compound in the presence of a caustic alkali and a solvent, or a transesterification method in which a bifunctional phenolic compound is transesterified with diethyl carbonate in the presence of a catalyst. Can be mentioned. The aromatic polycarbonate preferably has a viscosity average molecular weight of 10,000 to 100,000. Here, the bifunctional phenol compound is 2,2'-bis (4-hydroxyphenyl) propane, 2,2'-bis (4-hydroxy-3,5-dimethylphenyl) propane, bis (4-hydroxyphenyl) propane. Phenyl) methane, 1,1′-bis (4-hydroxyphenyl) ethane, 2,2′-bis (4-hydroxyphenyl) butane, 2,2′-bis (4-hydroxy-3,5
-Diphenyl) butane, 2,2'-bis (4-hydroxy-3,5-dipropylphenyl) propane, 1,1 '
-Bis (4-hydroxyphenyl) cyclohexane, 1
-Phenyl-1,1'-bis (4-hydroxyphenyl) ethane and the like, particularly preferably 2,2'-bis (4-hydroxyphenyl) propane [bisphenol A]. In the present invention, the bifunctional phenolic compounds may be used alone or in combination.

The method for stabilizing the physical properties of the flame-retardant styrenic resin of the present invention comprises (B) a flame retardant which does not melt at 300 ° C. or lower and (C) a dispersant as essential components. 0-100 resin, other resin or additives
This is a method in which the mixture is dispersed at a temperature of 150 ° C. by a mixer or a disperser such as a Henschel mixer, and then melt-kneaded at 150 to 300 ° C. by an extruder. At that time, a flame retardant other than those described above, a flame retardant auxiliary, a thermoplastic elastomer, a heat stabilizer such as an antioxidant or a tin-based heat stabilizer, a light resistance improver, a flow improver, a lubricant, a filler, a glass A reinforcing agent such as a fiber, a coloring agent such as a dye or a pigment, a foaming agent, an antistatic agent, a release agent, and the like can be added.

[0059]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention.

The measurements in the examples and comparative examples were performed using the following methods or measuring instruments.

(1) Reduced viscosity of rubber-modified styrene resin and polyphenylene ether ηsp / C A mixed solvent of 18 ml of methyl ethyl ketone and 2 ml of methanol was added to 1 g of rubber-modified styrene resin, and shaken at 25 ° C. for 2 hours.
Centrifuge at 18000 rpm for 30 minutes. The supernatant was taken out and the resin component was precipitated with methanol and then dried.

[0062] 0.1 g of the resin thus obtained is
In the case of rubber-modified polystyrene, it is dissolved in toluene, and in the case of rubber-modified acrylonitrile-styrene copolymer resin, it is dissolved in methyl ethyl ketone to obtain a solution having a concentration of 0.5 g / dl. The solution falling time T ₁ (second) was measured at 30 ° C. On the other hand, the falling time T ₀ (second) of pure toluene or pure methyl ethyl ketone was measured separately using the same viscometer, and calculated by the following formula.

Ηsp / C = (T ₁ / T ₀ −1) / C C: polymer concentration (g / dl) On the other hand, regarding the reduced viscosity ηsp / C of polyphenylene ether, 0.1 g is dissolved in chloroform and the concentration is reduced. 0.
A solution of 5 g / dl was prepared and measured in the same manner as above.

(2) Izod Impact Strength Measured at 23 ° C. by a method according to ASTM-D256. (1/4 inch test piece, no notch) (3) Surface Impact Strength Surface impact strength was measured at 23 ° C. by a method similar to ASTM-D1709. Specifically, using a Dupont impact tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.), the tip diameter of the striker is 6.4 mmR,
A 5.2 mm long dart (weight 200 g) was molded into a compact (70 mm) on a pedestal having a pedestal diameter of 9.5 mm and a hole depth of 4.0 mm.
(mm square, 3mm thick molded body) Contact fixed to the surface, drop the load on the molded body from a height of up to 50cm, and reduce the weight of the load when 50% of the molded body is broken by 50% breaking load And a drop load was multiplied to calculate a 50% breaking energy. This 50% breaking energy was defined as surface impact strength. The unit is kgcm.

(4) Flame retardancy VB (Vertical Bur) conforming to UL-94
ning) method. (1/16 inch test piece) (5) Continuous productivity (stability of physical properties) Side-feedable twin-screw extruder (Werner Pf)
using ZSK-40mmφ manufactured by Leiderer, Inc.
Continuous melt extrusion was performed for 0 hour, the average quenching time of the pellets obtained every hour was measured, and the continuous productivity (quality stability) was evaluated from the change in flame retardancy.

In the case where PPE is used as one of the resin components, since the melt viscosity is high, the previously produced PP is used.
Use E / HIPS masterbatch.

The following components were used in Examples and Comparative Examples.

(A) Styrene resin (A) Rubber-modified styrene resin (HIPS) polybutadiene (weight ratio of cis 1,4 bond / trans 1,4 bond / vinyl 1,2 bond = 95/2/3) ( Nippon Zeon Co., Ltd., brand name Nipol 122 OSL)｝
Was dissolved in the following mixture to give a uniform solution.

Polybutadiene 10.5% by weight Styrene 74.2% by weight Ethylbenzene 15.0% by weight α-methylstyrene dimer 0.27% by weight t-butylperoxyisopropyl carbonate 0.03% by weight Is continuously supplied to a series four-stage reactor equipped with a stirrer, and the first stage has a stirring speed of 190 rpm and 126 rpm.
° C, the second stage is 50 rpm, 133 ° C, the third stage is 20 rpm
m, 140 ° C., and polymerization was performed at 20 rpm and 155 ° C. in the fourth stage. Subsequently, the polymerization liquid having a solid content of 73% was led to a devolatilizer to remove unreacted monomers and a solvent to obtain a rubber-modified aromatic vinyl resin. As a result of analyzing the obtained rubber-modified aromatic vinyl resin (referred to as HIPS), the rubber content was 1
The weight average particle diameter of the rubber was 2.1 μm, the reduced viscosity ηsp / c was 0.53 dl / g.

Rubber-unmodified styrene resin (GPPS) Polystyrene having a weight average molecular weight of 200,000 (produced by Asahi Kasei Kogyo Co., Ltd.) was used (referred to as GPPS).

(B) Polyphenylene ether (PPE)
After the inside of a stainless steel reactor having an oxygen inlet at the bottom of the reactor and having a cooling coil and stirring blades inside was sufficiently replaced with nitrogen, 54.8 g of cupric bromide, di-n-
1110 g of butylamine and 20 liters of toluene,
8.75 kg of 2,6-xylenol was dissolved in a mixed solvent of 16 liters of n-butanol and 4 liters of methanol and charged into the reactor. Oxygen was continuously blown into the reactor while stirring, and polymerization was performed for 90 minutes while controlling the internal temperature to 30 ° C. After completion of the polymerization, the precipitated polymer was separated by filtration. A mixed solution of methanol / hydrochloric acid was added thereto to decompose the remaining catalyst in the polymer, further sufficiently washed with methanol, and dried to obtain a powdery polyphenylene ether (referred to as PPE-1). The reduced viscosity ηsp / C was 0.41 dl / g.

(C) Flame retardant (B) Bromine flame retardant In a reactor equipped with a heating stirrer, bromine (B
r2) 400 parts by weight were added, and while maintaining the temperature at 15 ° C., 1.8 parts by weight of aluminum chloride (AlCl 3) was added and stirred. Then, 18.2 parts by weight of diphenylethane melted under a nitrogen atmosphere were added in 23 minutes, and 1
The mixture was stirred at a temperature of 0 to 17 ° C for 30 minutes, and subsequently heated at 59 ° C for 3.5 hours. Then, 200 parts by weight of water was added to the reactor, and excess bromine was distilled off. The crude decabromodiphenylethane remaining in the reactor is washed with water, dried in air overnight at room temperature, and at 210 ° C. for 24 hours for a further 2 hours.
It was dried at 50 ° C. for 7 hours. The decabromodiphenylethane obtained in this way is called DBDE.

Antimony trioxide Antimony trioxide manufactured by Suzuhiro Chemical Co., Ltd. was used (Sb
₂ O ₃ ).

Fluorine-based flame retardant Commercially available polytetrafluoroethylene (trade name: Teflon 6J (manufactured by Mitsui Dupont Fluorochemicals, Inc., PTF)
E) was used.

(D) Phosphorus-based flame retardant: triphenyl phosphate (TPP) A commercially available aromatic phosphate ester monomer [trade name TPP (trade name: TPP) manufactured by Daihachi Chemical Industry Co., Ltd.] was used.
It is a powder flame retardant with a melting point of 50 ° C.

(E) Dispersant (C) Ethylene bisstearylamide (EBS) A product of Kao Corporation was used (referred to as EBS).

Zinc stearate (ZS) manufactured by Dainichi Chemical Co., Ltd. (referred to as ZS).

Liquid paraffin (MO) Used by Esso Oil Co., Ltd. (referred to as MO).

Polyethylene Wax (PE) A polyethylene wax having a molecular weight of 5,000 manufactured by Sanyo Chemical Industries, Ltd. was used (referred to as WAX).

Examples 1 to 6 and Comparative Examples 1 to 3 The compositions described in Tables 1 and 2 were produced by the following processes.
The composition was evaluated. The results are shown in Tables 1 and 2.
In Tables 1 and 2, the composition of the composition is part by weight.

Process (Method of Adding Each Component): I: Side-feedable twin-screw extruder (Werner)
(ZSK-40mmφ, manufactured by Pfleiderer Co.), and only (A) and (B) were simultaneously fed from the main feeder and melt-extruded at 230 ° C. to form pellets. (Comparative Example) II-1: First, (B) 25 parts of DBDE / Sb ₂ O ₃ and (C)
The mixture (master batch) obtained by mixing in a Henschel mixer at ℃ was introduced into the twin screw extruder together with (A), and was melt-extruded at 230 ° C. to pelletize. (Examples) II-2: First, a mixture (masterbatch) obtained by mixing (B) Sb ₂ O ₃ and (C) MO at 25 ° C. in a Henschel mixer is mixed with (B) DBDE and (A) The mixture was introduced into the above twin screw extruder together with HIPS and melt-extruded at 230 ° C. to form pellets. (Examples) II-3: First, a mixture (masterbatch) obtained by mixing (B) PTFE and (C) EBS in a Henschel mixer at 25 ° C. was mixed with (B) TPP, (A) HIPS and PP.
The mixture was introduced into the above twin screw extruder together with E and melt-extruded at 230 ° C. to form pellets. (Example) III-1: In process II, (A) HIPS (B)
A similar experiment was performed except that DBDE / Sb ₂ O ₃ (C) EBS was mixed simultaneously in a Henschel mixer.
Was. (Example) III-2: (A) GPPS (B) Sb ₂ O ₃ (C) WAX
Was mixed in a Henschel mixer at 25 ° C., and the mixture (masterbatch) obtained was mixed with (B) DBDE and (A) H
The same experiment as in Process II was conducted by introducing the above-mentioned twin screw extruder together with IPS. (Example)

[0082]

[Table 1]

[0083]

[Table 2]

According to Tables 1 and 2, in the case of process I,
The impact strength is significantly reduced due to the poor dispersion of (B),
In the case of processes II and III, it can be seen that the dispersibility of (B) is improved and the impact strength and continuous productivity are improved.

[0085]

According to the present invention, not only the physical properties of the styrenic resin are improved, but also the stability of the melt extrusion is improved, and as a result, it is possible to improve the productivity and the stability of the physical properties during production.

The composition obtained by this method is VT
R, distribution board, television, audio player, condenser, household outlet, boombox, video cassette, video disk player, air conditioner, humidifier, electric home appliance housing such as electric hot air machine, chassis or parts, CD-ROM main Frame (mechanical chassis), printer, fax, PPC, CRT, word processor copier, electronic cash register, office computer system, floppy disk drive, keyboard, type, ECR, calculator, toner cartridge, OA equipment housing such as telephone, Chassis or parts, connector, coil bobbin, switch, relay, relay socket, LED, variable condenser, AC adapter, FBT high-voltage bobbin, FBT case, IFT coil bobbin, jack, volume shaft, motor Electronic and electrical materials, such as electrical components, and automotive materials such as instrument panels, radiator grills, clusters, speaker grills, louvers, console boxes, defroster garnishes, ornaments, fuse boxes, relay cases, connector shift tapes, etc. The role played by these industries is great.

Claims (3)

[Claims] 1. At least a part of (B) a flame retardant which does not melt at 300 ° C. or lower is added to a (C) dispersant in an amount of 0 to 1
A method for stabilizing physical properties of a flame-retardant styrenic resin, which comprises melting and kneading at 150 to 300 ° C together with (A) a styrenic resin after treatment at 00 ° C. 2. The method according to claim 1, wherein (A) a styrene resin and (B)
The flame retardant that does not melt at 300 ° C. or less
A method for stabilizing physical properties of a flame-retardant styrene-based resin, comprising dispersing at from 100 to 100 ° C and then melt-kneading at from 150 to 300 ° C. 3. The flame-retardant styrene-based composition according to claim 1, wherein (B) is a flame retardant selected from antimony oxide, a fluororesin, and a bromine-based flame retardant and / or (C) is a higher fatty acid amide or liquid paraffin. Method for stabilizing physical properties of resin.