JP6894205B2 - Method for producing styrene resin composition - Google Patents

Description

The present invention relates to a method for producing a styrene-based resin composition, and a styrene-based flame-retardant resin composition using the styrene-based resin composition.

Rubber-modified styrene resins are used in a wide range of applications. In particular, flame-retardant resins include word processors, personal computers, printers, OA equipment such as copiers, and home appliances such as televisions, VTRs, and audio. It is used in a wide variety of fields. Conventionally, various flame retardants have been proposed in order to impart flame retardancy to styrene-based resins, and among them, halogen-containing organic compounds which are inexpensive and have an excellent balance of physical properties are often used. However, in recent years, the movement to regulate halogen-containing organic compounds has become active mainly in Europe, and therefore, the demand for flame-retardant resins and flame-retardant resin compositions containing no halogen element is increasing. Phosphorus-based flame retardants are being studied as alternative flame retardants to such halogen-based flame retardants. Phosphorus-based flame retardants are generally used in combination with a resin containing a carbonized layer forming component in order to exhibit a flame retardant effect.

In recent years, as a method of making a styrene resin flame-retardant from the viewpoint of economy and work environment, a masterbatch is prepared by melting and mixing a high-concentration flame retardant and a carbonized layer forming component with a styrene resin in advance using an extruder. There is an increasing number of methods for producing a styrene-based flame-retardant resin composition having desired physical properties and flame retardancy by using the styrene-based resin composition and the styrene-based resin obtained as described above. Patent Document 1 is mentioned as a masterbatch technique.

Furthermore, in recent years, in the fields of OA equipment and home appliances, the appearance of plastic exterior parts is regarded as important.

Japanese Unexamined Patent Publication No. 2014-205802

When the flame retardant and the carbonized layer forming component are melt-mixed with the styrene resin by an extruder, the carbonized layer forming component has a high melting point, and an undissolved substance is generated depending on the kneading method. When the styrene-based flame-retardant resin composition obtained by using the styrene-based resin composition having the undissolved substance is molded, molding defects such as flashes occur.

The present invention has been made in view of such circumstances, and provides a method for producing a styrene-based resin composition having excellent uniformity.

According to the present invention, there is provided a styrene-based resin composition having excellent uniformity, which comprises a composition containing (A) a styrene-based resin and (B) a polyphenylene ether-based resin.

That is, the present invention is as follows.
1. 1. A method for producing a styrene-based resin composition containing (A) a styrene-based resin and (B) a polyphenylene ether-based resin.
The (A) styrene resin and (B) polyphenylene ether resin are supplied to a twin-screw extruder having at least one kneading portion, and the resin temperature immediately after the downstream side of any of the kneading portions is 250 ° C. or higher and 266. A method for producing a styrene-based resin composition, which comprises melt-kneading at a temperature of ° C. or lower.
2. In a total of 100 parts by mass of the (A) styrene resin and the (B) polyphenylene ether resin, 93 to 25 parts by mass of the (A) styrene resin and 7 to 75 parts by mass of the (B) polyphenylene ether resin. The method for producing a styrene-based resin composition according to 1 above, which comprises a part.
3. 3. A method for producing a styrene resin composition containing (A) a styrene resin, (B) a polyphenylene ether resin, and (C) a phosphorus flame retardant.
From the first supply section of a twin-screw extruder having a first supply section, a second supply section, and at least one kneading section arranged between the first supply section and the second supply section. Supplying (A) styrene resin and (B) polyphenylene ether resin,
The phosphorus-based flame retardant (C) is supplied from the second supply unit,
A method for producing a styrene-based resin composition, which comprises melt-kneading so that the resin temperature immediately after the downstream side of any of the kneading portions is 250 ° C. or higher and 266 ° C. or lower.
4. In a total of 100 parts by mass of the (A) styrene resin and the (B) polyphenylene ether resin, the (A) styrene resin is 93 to 25 parts by mass and the (B) polyphenylene ether resin is 7 to 75 parts by mass. It is a department
3. The above 3, wherein the (C) phosphorus-based flame retardant is used in an amount of 6 to 65 parts by mass with respect to a total of 100 parts by mass of the (A) styrene resin and the (B) polyphenylene ether-based resin. A method for producing a styrene resin composition.
5. The method for producing a styrene-based resin composition according to 3 or 4, wherein the phosphorus-based flame retardant (C) is an aromatic diol bis (diaryl phosphate) compound.
6. 5. The method for producing a styrene-based resin composition according to 5, wherein the aromatic diol bis (diaryl phosphate) compound is a bisphenol A bis (diaryl phosphate) compound .

According to the present invention, a styrene-based resin composition having excellent uniformity can be produced by melt-mixing under specific manufacturing conditions using a twin-screw extruder, and the styrene-based resin composition is used. However, the styrene-based flame-retardant fat composition can be easily produced by diluting with a styrene-based resin. The obtained styrene-based flame-retardant resin composition can easily obtain a molded product having an excellent appearance of the molded product.

It is a schematic diagram which shows the manufacturing process of this invention.

The production method of the present invention is to melt-mix a styrene-based resin composition containing (A) a styrene-based resin and (B) a polyphenylene ether-based resin under specific production conditions using a twin-screw extruder. It is characterized by.

As a method for producing the styrene resin composition, a styrene resin composition having excellent uniformity can be obtained by the method shown below.

FIG. 1 is a schematic view of a twin-screw extruder used in the manufacturing method of the present invention. Hereinafter, a method for producing a styrene-based resin composition using this twin-screw extruder will be described.

FIG. 1 shows the resin composition located on the downstream side from the first supply section 2 located on the upstream side of the twin-screw extruder 1 between the discharge port (die) 5 and the kneading section 3 and the vacuum vent port from the upstream side. 4. The second supply unit 6 is provided. Further, a thermometer 7 was provided immediately after the downstream side of the kneading portion 3 and at the resin composition discharge port for observing the resin temperature. Even if the second supply unit 6, the vacuum vent 4, and the thermometer 7 are not provided, this production is not affected.

The resin temperature of the thermometer immediately after the downstream side of the kneading portion 3 is preferably 250 ° C. or higher, and if it is lower than 250 ° C., the (B) polyphenylene ether-based resin in the styrene-based resin composition becomes poorly dispersed.

The position of the kneading portion 3 is not particularly limited. When installing the second supply unit, the position and number are not limited as long as it is between the first supply unit and the second supply unit. The specific configuration is not particularly limited, and a general configuration can be used, and it is preferable that the resin temperature in the vicinity of the downstream side of any of the kneading portions 3 is 250 ° C. or higher. As a specific configuration, the following kneading discs (1) to (3) are combined.
(1) Kneading block with L / D = 0.4 to 1.5, B = 3 to 10 sheets, α = 20 to 80 degrees (2) L / D = 0.4 to 1.5, B = Kneading block with 3 to 10 sheets and α = 90 degrees (3) Kneading block with L / D = 0.4 to 1.5, B = 3 to 10 sheets and α = 100 to 170 degrees (However, L is the length of the kneading block (mm), D is the screw diameter (mm), B is the number of blades constituting the kneading block (sheets), and α is the twist angle (degrees) between two adjacent blades. ).)

(C) Phosphorus-based flame retardant can be supplied from the second supply unit. When the phosphorus-based flame retardant is a liquid, there is a method in which a liquid addition nozzle is used and a known liquid transport pump is used to raise the discharge pressure to a level higher than the resin pressure and supply the agent. When the phosphorus-based flame retardant is a solid, there is a method of supplying it by using a side feeder instead of the liquid addition nozzle.

As the (A) styrene resin used in the present invention, it is preferable to use a rubber-modified styrene resin. The rubber-modified styrene resin is a resin obtained by polymerizing an aromatic vinyl compound-based monomer and adding a rubber-like polymer to perform rubber modification. As the polymerization method, it can be produced by a known method, for example, a lumpy polymerization method, a lumpy / suspension two-stage polymerization method, a solution polymerization method or the like. As the aromatic vinyl compound-based monomer, known ones such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, and p-methylstyrene can be used, but styrene is preferable. In addition, styrene-based monomers such as acrylonitrile, (meth) acrylic acid, and (meth) acrylic acid ester that can be copolymerized with these aromatic vinyl compound-based monomers, and monomers other than maleic anhydride and the like are also available. Any material may be used as long as it does not impair the performance of the resin composition. Further, in the present invention, a cross-linking agent such as divinylbenzene may be added to the styrene-based monomer for polymerization.

Examples of the rubber-like polymer contained in the rubber-modified styrene resin include polybutadiene, styrene-butadiene random or block copolymer, polyisoprene, polychloroprene, styrene-isoprene random, block or graft copolymer, and ethylene-propylene. Examples thereof include rubber and ethylene-propylene-diene rubber, but polybutadiene and styrene-butadiene random, block or graft copolymers are particularly preferable. In addition, these may be partially hydrogenated. Examples of rubber-modified styrene-based resins include impact-resistant polystyrene (HIPS), ABS resin (acrylonitrile-butadiene-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), and AES resin (acrylonitrile-ethylene). Propylene-styrene copolymer), MBS resin (methylmethacrylate-butadiene-styrene copolymer) and the like.

The molecular weight of the aromatic vinyl polymer in the rubber-modified styrene resin is not particularly limited, but the reduced viscosity (ηsp / C) is preferably 0.5 to 1.0.

The content of the rubber-like polymer in the rubber-modified styrene resin is not particularly limited, but is preferably 3 to 10% by mass.

The average particle size of the rubber-like polymer in the rubber-modified styrene resin is not particularly limited, but is preferably 0.4 to 5.0 μm by mass. More preferably, it is 1.0 to 4.0 μm mass%.

The (B) polyphenylene ether-based resin used in the present invention is a polymer having the structural unit shown in Chemical formula 1 below in the main chain, and may be either a homopolymer or a copolymer.

（ここで、Ｒ１、Ｒ２、Ｒ３、Ｒ４は、それぞれ独立に水素原子、ハロゲン原子、第１級若しくは第２級アルキル基、アリール基、アミノアルキル基、ハロアルキル基、炭化水素オキシ基、又はハロ炭化水素オキシ基を表す。ただし、Ｒ１、Ｒ２がともに水素原子になることはない。）

(Here, R1, R2, R3, and R4 are independently hydrogen atoms, halogen atoms, primary or secondary alkyl groups, aryl groups, aminoalkyl groups, haloalkyl groups, hydrocarbon oxy groups, or halocarbonated groups. Represents a hydrocarbon oxy group. However, neither R1 nor R2 becomes a hydrogen atom.)

Typical examples of homopolymers of polyphenylene ether-based resins are poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, and poly (poly (2-methyl-6-ethyl-1,4-phenylene) ether. 2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n-propyl-1,4-) Phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-phenylene) ether, poly (2-methyl-6-) Examples thereof include chloroethyl-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether and the like. .. Examples of copolymers include 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-triethylphenol copolymer, 2,6-. 2,6-dialkylphenol / 2,3,6-tri such as diethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer, etc. Alkylphenol copolymer, graft copolymer obtained by graft-polymerizing styrene on poly (2,6-dimethyl-1,4-phenylene ether), 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer Examples thereof include a graft copolymer obtained by graft-polymerizing styrene.

The polyphenylene ether resin is preferably a poly (2,6-dimethyl-1,4-phenylene) ether or a 2,6-dimethylphenol / 2,3,6-trimethylphenol random copolymer, and particularly preferably. It is a poly (2,6-dimethyl-1,4-phenylene) ether.

The ultimate viscosity of the polyphenylene ether resin is preferably 0.2 to 0.8 dl / g, more preferably 0.3 to 0.5 dl / g, as measured in chloroform at 30 ° C.

The amount of (A) styrene resin and (B) polyphenylene ether resin added is not particularly limited, but the total of (A) styrene resin 93 to 25 parts by mass and (B) polyphenylene ether resin 7 to 75 parts by mass is It is preferably 100 parts by mass. More preferably, the total of (A) styrene-based resin 91 to 30 parts by mass and (B) polyphenylene ether-based resin 9 to 70 parts by mass is 100 parts by mass.

Examples of the phosphorus-based flame retardant include red phosphorus, organic phosphate compounds, phosphazene compounds, phosphinates, phosphonates, phosphoramide compounds and the like, and in particular, aromatic diol bis (diaryl) represented by the following formula 2. Phosphate) compounds are preferred.

（ここで、ｎは１〜５の整数であり、Ａｒ１〜Ａｒ４は炭素数６〜１５のフェニル基又はアルキル置換フェニル基を表し、Ｘは下式に示す化３で表わされるＸ１、Ｘ２、Ｘ３、Ｘ４、又はＸ５から選ばれる置換基である。）

(Here, n is an integer of 1 to 5, Ar1 to Ar4 represent a phenyl group having 6 to 15 carbon atoms or an alkyl-substituted phenyl group, and X represents X1, X2, X3 represented by Chemical formula 3 shown in the following formula. , X4, or X5.)

More preferably, it is a bisphenol A bis (diaryl phosphate) compound represented by Chemical formula 4 below.

（ここで、ｎは１〜５の正数であり、Ａｒ１〜Ａｒ４は炭素数６〜１５のフェニル基又はアルキル置換フェニル基を表す。）

(Here, n is a positive number of 1 to 5, and Ar1 to Ar4 represent a phenyl group having 6 to 15 carbon atoms or an alkyl-substituted phenyl group.)

Specific examples of the bisphenol A bis (diaryl phosphate) compound include bis (diphenyl phosphate), bis (ditril phosphate), and (dixylenyl phosphate) compounds of bisphenol A, and bisphenol A bis (diphenyl phosphate) is preferable. Diphenyl phosphate) compound.

The amount of the phosphorus-based flame retardant added is not particularly specified, but the total of (A) 93 to 25 parts by mass of the styrene resin and 7 to 75 parts by mass of the (B) polyphenylene ether resin is 100 parts by mass. The amount of the (C) phosphorus-based flame retardant is preferably 6 to 65 parts by mass. More preferably, it is (C) a phosphorus-based flame retardant of 8 to 60 parts by mass.

Further, in order to obtain the styrene resin composition of the present invention, a colorant, a plasticizer, a lubricant, a heat stabilizer, an ultraviolet absorber, a filler, a reinforcing agent and the like are further added as additives according to the purpose. Can be done.

For example, since many black molded products are used, carbon black can be added as a pigment to the styrene resin composition of the present invention as needed to produce a styrene resin composition.
Further, from the viewpoint of fluidity and scratch resistance of the molded product of the styrene resin composition, a polyolefin wax, a higher fatty acid amide, a higher carboxylic acid metal salt and the like can be used as the lubricant. Further, talc can be added as a filler. When talc is added, the volume average particle size is not particularly limited, but is preferably 2 to 15 μm, and more preferably 5 to 10 μm. The amount to be added is preferably 10 parts by mass or less of talc with respect to 100 parts by mass of the total of the (A) styrene resin and the (B) polyphenylene ether resin.

The styrene-based resin composition of the present invention can be diluted with an arbitrary styrene-based resin to obtain a styrene-based flame-retardant resin composition. The dilution amount of the styrene-based resin can be arbitrarily determined depending on the amount of the flame retardant of the styrene-based resin composition and the required flame retardancy of the styrene-based flame-retardant resin composition. It is preferably 0 to 80 parts by mass of the styrene resin with respect to 100 to 20 parts by mass of the styrene resin composition, and more preferably 0 to 0 parts by mass of the styrene resin with respect to 100 to 25 parts by mass of the styrene resin composition. It is 75 parts by mass. The melt-kneading method is not particularly limited, and for example, a method such as a Banbury mixer, a kneader, a single-screw extruder, or a twin-screw extruder can be adopted, and in particular, a single-screw extruder or a twin-screw extruder can be adopted. It is preferable to use a machine. For the screw of the single-screw extruder, full flight, dalmage, pin, madock, etc. can be adopted, but it is particularly preferable to use dalmage.

The molded product of the styrene-based flame-retardant resin composition is used for OA equipment such as word processors, personal computers, printers and copiers, and home appliances such as TVs, VTRs and audios. Further, the molding method is not particularly limited, but is preferably injection molding, and a hot runner molding method using a large molding machine or a gas assist injection method is also applied.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

[(A) Styrene-based resin]
The styrene-based resin (A) used had a reduced viscosity of 0.69 dl / g, a gel content of 26.6% by weight, and contained a rubber-like polymer in an amount of 9.4% by mass, and the volume average particles of the rubber-like polymer. It is a rubber-modified styrene resin (HI) of high cis polybutadiene rubber having a diameter of 2.8 μm and all containing cis-1,4 bonds in a ratio of 90 mol% or more.
The reduced viscosity, gel content, rubbery polymer content and volume average particle size referred to here were measured by the following methods.

<Reduced viscosity>
A mixed solvent of 15 ml of methyl ethyl ketone (MEK) and 15 ml of acetone is added to 1 g of a styrene resin, dissolved by shaking at 25 ° C. for 2 hours, the insoluble matter is precipitated by centrifugation, the supernatant is taken out by decantation, and 500 ml of methanol is used. Is added to precipitate the resin component, and the insoluble component is filtered and dried. The resin component obtained by the same operation is dissolved in toluene to prepare a sample solution having a polymer concentration of 0.4% (weight / volume). This sample solution and pure toluene were kept at a constant temperature of 30 ° C., and the number of seconds of solution flowing down was measured with an Ubbelohde viscometer, and calculated by the following formula.

η _sp / C = (t1 / t0-1) / C
t0: Number of seconds of pure toluene flowing down t1: Number of seconds of sample solution flowing down C: Polymer concentration

<Gel content>
Styrene-based resin is added to toluene at a ratio of 2.5% by mass, dissolved by shaking at 25 ° C. for 2 hours, and then the insoluble matter (gel content) is precipitated by centrifugation (rotation speed 10000-14000 rpm, separation time 30 minutes). Then, the supernatant is removed by decantation to obtain a gel. Next, the swollen gel is pre-dried at 100 ° C. for 2 hours and then dried in a vacuum dryer at 120 ° C. for 1 hour. It was cooled to room temperature with a desiccator, weighed precisely, and calculated by the following formula.
Gel fraction (%) = ((ba) / S) x 100
a: Centrifugal sedimentation tube weight b: Dry gel + Centrifugal sedimentation tube weight S: Sample resin weight

<Rubber polymer content>
Dissolve a styrene resin in chloroform, add a certain amount of iodine monochloride / carbon tetrachloride solution, leave it in the dark for about 1 hour, add 15% by mass potassium iodide solution and 50 ml of pure water, and add excess monochloride. Iodine was titrated with a 0.1 N sodium thiosulfate / ethanol aqueous solution and calculated from the amount of iodine monochloride added.

<Volume average particle size of rubber-like polymer>
The styrene resin was completely dissolved in dimethylformamide and measured with a laser diffraction type particle size distribution device. As a measuring device, a laser diffraction type particle analyzer "LS-230 type" manufactured by Beckman Coulter Co., Ltd. was used.

[(B) Polyphenylene ether-based resin]
"PX100F" (extreme viscosity: 0.38 dl / g) manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used.

[(C) Phosphorus flame retardant]
"CR-741" (phosphorus content 8.2% by mass) manufactured by Daihachi Chemical Industry Co., Ltd. was used.

〔talc〕
"FH108" (volume average particle size: 8 μm) manufactured by Fuji Talc Industry Co., Ltd. was used.

[Manufacturing of styrene resin composition]
After premixing (A) styrene resin, (B) polyphenylene ether resin, and talc in the blending amount (parts by mass) shown in Table 1 with a Henschel mixer type mixer, the first supply part of the twin screw extruder. After a fixed amount of water is supplied and melt-kneaded, the phosphorus-based flame retardant (C) is further supplied from the liquid addition nozzle of the extruder at the blending ratio shown in Table 1, melt-kneaded to form a strand, and cooled with water. After that, it was led to a pelletizer and pelletized to obtain a flame retardant masterbatch. At the time of premixing, a mixture of sodium aluminosilicate and A-type zeolite, zinc stearate, polyethylene wax, and ethylene bisstearic acid amide were also added at the same time.

As the twin-screw extruder, "TEM-26SS" (screw diameter Φ26 mm, L / D = 56) manufactured by Toshiba Machine Co., Ltd. was used. The set cylinder temperature was 260 ° C. (conveyed portion) to 260 ° C. (kneaded portion) to 230 ° C. (measuring portion to die portion), a discharge rate of 30 kg / h, and a screw rotation speed of 300 rpm. Table 1 shows the thermometer values installed immediately after the downstream side of the kneading portion and at the discharge port during extrusion.

Using the following kneading discs A to J, the examples were carried out by assembling the kneading portion so that the thermometer immediately after the downstream side of the kneading portion had a temperature of 260 ° C. or higher. The comparative example was carried out by assembling the structure of the kneading part so that the thermometer immediately after the downstream side of the kneading part was 240 ° C. or less. Further, the configuration on the downstream side of the kneading portion was the same in both the examples and the comparative examples.
A: L / D = 1.03, B = 7, α = 45 degrees C: L / D = 1.03, B = 5, α = 45 degrees E: L / D = 0.76, B = 5 sheets, α = 45 degrees F: L / D = 1.03, B = 7 sheets, α = 90 degrees G: L / D = 1.03, B = 5 sheets, α = 90 degrees H: L / D = 0.76, B = 5, α = 90 degrees I: L / D = 1.03, B = 7, α = 135 degrees J: L / D = 0.76, B = 5, α = 135 degrees L is the length (mm) of the kneading block and the progressive screw block, D is the screw diameter (mm), B is the number of blades that make up the kneading block (sheets), and α is the length of the two adjacent blades. Represents the twist angle (degrees) between

[Manufacturing of styrene-based flame-retardant resin composition]
The styrene-based resin composition is premixed with a Henschel mixer-type mixer at the blending amounts (parts by mass) shown in Tables 2 and 3, and then supplied to a single-screw extruder and a twin-screw extruder for melt-kneading. Then, it was made into a strand, cooled with water, guided to a pelletizer, and pelletized to obtain a styrene-based flame-retardant resin composition.

As the single-screw extruder, IKG's "PMS40-28" (screw diameter Φ40 mm, L / D = 28, dalmage screw) was used. The cylinder temperature was 180 ° C. (conveyed portion) to 200 ° C. (kneading to weighing portion) to 230 ° C. (die portion), and the screw rotation speed was 100 rpm.

As the twin-screw extruder, "TEM-26SS" (screw diameter Φ26 mm, L / D = 56) manufactured by Toshiba Machine Co., Ltd. was used. The cylinder set temperature was 180 ° C. (conveyed portion) to 230 ° C. (kneading portion-measuring portion-die portion), a discharge rate of 30 kg / h, and a screw rotation speed of 300 rpm.

〔Evaluation method〕
The various measurements shown in Examples and Comparative Examples were carried out by the following methods. The results are shown in Tables 1 to 3.

<Dispersiveness>
After heating and drying the pellets of the styrene resin composition at 70 ° C. for 3 hours in a press molding machine (“MP-2F” manufactured by Toyo Seiki Seisakusho Co., Ltd.), place about 100 g on the edge of the press plate and set the temperature at 200 ° C. The styrene resin composition that had melted and squeezed out was slowly pulled to prepare a film having a thickness of about 30 to 50 μm, which was visually observed. The evaluation results are described as follows.
◯: No lumps ×: There are lumps with poor dispersion

(Flame retardance>
After heating and drying the pellets of the styrene-based flame-retardant resin composition at 70 ° C. for 3 hours, a difficulty of 127 × 12.7 × 0.8 mm is used in an injection molding machine (“J100E-P” manufactured by Japan Steel Works, Ltd.). A test piece for flame evaluation was molded. Using such a test piece, a combustion test was conducted based on the vertical combustion test method (UL94) of Subject 94 of Underwriters Laboratories, Inc. of the United States.

(Plate appearance>
After heating and drying the pellets of the styrene-based flame-retardant resin composition at 70 ° C. for 3 hours, a three-stage plate mold (molded product dimensions: vertical) is used in an injection molding machine (“J100E-P” manufactured by Japan Steel Works, Ltd.). / Width / Depth = 90 x 45 x 3,2,1 mm) Continuously at cylinder temperature: 220 ° C, mold temperature: 40 ° C, cooling time: 30 seconds, injection speed: 30%, injection time: 5 seconds Molded. The flash generated in the molded product was visually observed. The evaluation results are described as follows.
○: No flash occurred ×: Flash occurred

1 Biaxial extruder 2 1st supply part 3 Kneading part 4 Vacuum vent port 5 Resin composition discharge port (die)
6 Second supply unit 7 Thermometer

Claims (6)

A method for producing a styrene-based resin composition containing (A) a styrene-based resin and (B) a polyphenylene ether-based resin.
The (A) styrene resin and (B) polyphenylene ether resin are supplied to a twin-screw extruder having at least one kneading portion, and the resin temperature immediately after the downstream side of any of the kneading portions is 250 ° C. or higher and 266. A method for producing a styrene-based resin composition, which comprises melt-kneading at a temperature of ° C. or lower. In a total of 100 parts by mass of the (A) styrene resin and the (B) polyphenylene ether resin, the (A) styrene resin is 93 to 25 parts by mass, and the (B) polyphenylene ether resin is 7 to 75 parts by mass. The method for producing a styrene-based resin composition according to claim 1, wherein the portion is a part. A method for producing a styrene resin composition containing (A) a styrene resin, (B) a polyphenylene ether resin, and (C) a phosphorus flame retardant.
From the first supply section of a twin-screw extruder having a first supply section, a second supply section, and at least one kneading section arranged between the first supply section and the second supply section. Supplying (A) styrene resin and (B) polyphenylene ether resin,
The phosphorus-based flame retardant (C) is supplied from the second supply unit,
A method for producing a styrene-based resin composition, which comprises melt-kneading so that the resin temperature immediately after the downstream side of any of the kneading portions is 250 ° C. or higher and 266 ° C. or lower. In a total of 100 parts by mass of the (A) styrene resin and the (B) polyphenylene ether resin, 93 to 25 parts by mass of the (A) styrene resin and 7 to 75 parts by mass of the (B) polyphenylene ether resin. It is a department
The third aspect of claim 3, wherein the (C) phosphorus-based flame retardant is used in an amount of 6 to 65 parts by mass with respect to a total of 100 parts by mass of the (A) styrene-based resin and the (B) polyphenylene ether-based resin. Method for producing a styrene-based resin composition. The method for producing a styrene resin composition according to claim 3 or 4, wherein the phosphorus-based flame retardant (C) is an aromatic diol bis (diaryl phosphate) compound. The method for producing a styrene-based resin composition according to claim 5, wherein the aromatic diol bis (diaryl phosphate) compound is a bisphenol A bis (diaryl phosphate) compound.

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