JP7086650B2 - A flame-retardant styrene resin composition, a method for producing the same, and a molded product comprising the same. - Google Patents

Description

The present invention relates to a flame-retardant styrene resin composition having excellent transparency and flame retardancy, a method for producing the same, and a molded product comprising the same.

Utilizing its excellent moldability, styrene-based resins are used in many products such as food packaging containers, miscellaneous goods, building materials, automobile materials, information appliances, electronic parts, and home appliance housings.

On the other hand, styrene-based resin is flammable, and there is concern about its safety as a product. Therefore, in order to eliminate this flammability, studies on flame retardancy using various flame retardants have been conventionally conducted for the purpose of imparting flame retardancy to styrene-based resins.

However, the flame-retardant styrene resin has a problem that the transparency is significantly impaired.

Therefore, a technique for imparting flame retardancy while maintaining the transparency of a styrene resin has been studied in the past (Patent Documents 1 to 3). However, a styrene-based resin composition having sufficient transparency and flame retardancy has not been reported so far.

Japanese Unexamined Patent Publication No. 2002-09723 Japanese Patent Application Laid-Open No. 2002-003688 Japanese Unexamined Patent Publication No. 2001-316543

The present invention is to provide a flame-retardant styrene resin composition having excellent transparency and flame retardancy, a method for producing the same, and a molded product comprising the same.

（ここで、ｎは整数１～１０の重合度を表す。また、Ｘ_１およびＸ_３はそれぞれ独立に整数１～５の臭素原子であり、Ｘ_２は整数０～４の臭素原子を表す。）
（２）．（１）に記載の難燃性スチレン系樹脂組成物の製造方法であって、溶融混練時の樹脂温度が２６５℃以上である難燃性スチレン系樹脂組成物の製造方法。
（３）．（１）に記載の難燃性スチレン系樹脂組成物を成形してなる成形体。 (1). When (A) a styrene-based resin and (B) brominated polyphenylene ether represented by the following general formula (1) are contained, and (A) the styrene-based resin is 100 parts by mass, (B) brominated polyphenylene. The amount of ether compounded is 27 to 40 parts by mass, the total light transmittance is 70% or more and the cloudiness is 10.0% or less measured by a molded body having a thickness of 2.0 mm, and the degree of turbidity is 10.0% or less, and based on ASTM D7309 Resin A. A flame-retardant styrene resin composition having a measured total calorific value of 30.0 kJ / g or less.

(Here, n represents the degree of polymerization of integers 1 to 10. Further, X ₁ and X ₃ are independently bromine atoms of integers 1 to 5, and X ₂ represents bromine atoms of integers 0 to 4. )
(2). The method for producing a flame-retardant styrene-based resin composition according to (1), wherein the resin temperature at the time of melt-kneading is 265 ° C. or higher.
(3). A molded product obtained by molding the flame-retardant styrene resin composition according to (1).

According to the present invention, (B) the amount of brominated polyphenylene ether blended, the total light transmittance and cloudiness measured in a molded body having a thickness of 2.0 mm, and the total calorific value measured using a microscale combustion calorimeter. By specifying the above, a flame-retardant styrene resin composition having excellent transparency and flame retardancy can be obtained. Therefore, by using the flame-retardant styrene resin composition of the present invention, molded products such as general miscellaneous goods having excellent transparency and flame retardancy, housings of lighting devices, and the like can be obtained.

Examples of the (A) styrene resin used in the present invention include polystyrene resin, acrylonitrile-styrene copolymer (AS resin), methyl methacrylate-styrene copolymer (MS resin), and methacrylate-styrene copolymer. Can be mentioned. Of these, polystyrene resin is preferable.

The (B) brominated polyphenylene ether used in the present invention has a structure represented by the following general formula (1).

上式中、ｎは整数１～１０の重合度を表す。また、Ｘ_１およびＸ_３はそれぞれ独立に整数１～５の臭素原子であり、Ｘ_２は整数０～４の臭素原子を表す。

In the above formula, n represents the degree of polymerization of integers 1 to 10. Further, X ₁ and X ₃ are independently bromine atoms having integers 1 to 5, and X ₂ represents bromine atoms having integers 0 to 4.

Specific examples thereof include Emerald Innovation 1000 manufactured by Chemtura.

In the present invention, the blending amount of (B) brominated polyphenylene ether is 27 to 40 parts by mass when (A) styrene resin is 100 parts by mass. With this blending amount, a flame-retardant styrene resin composition having excellent flame retardancy and transparency can be obtained.

In the present invention, a known mixing technique can be applied to the mixing method of the flame-retardant styrene resin composition. For example, a mixture previously mixed by a mixing device such as a mixer type mixer, a V type blender, and a tumbler type mixer can be further melt-kneaded to obtain a uniform flame-retardant resin composition. There are no particular restrictions on melt kneading, and known melting techniques can be applied. Suitable melt-kneading devices include Banbury type mixers, kneaders, rolls, single-screw extruders, special single-screw extruders, twin-screw extruders and the like. Further, there is a method of separately adding various additives from the middle of a melt-kneading device such as an extruder.

In the present invention, the temperature of the flame-retardant styrene resin composition at the time of melt-kneading is 265 ° C. or higher in terms of resin temperature.

Known techniques can be applied to the molding method of the molded product of the present invention. For example, there are methods such as injection molding, press molding, extrusion molding, and blow molding.

Other additives can be added as long as the object of the present invention is not impaired. For example, antioxidants such as phenolic antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, fatty acid-based lubricants for lubricants, aliphatic amide-based lubricants, metal soap-based lubricants, colorant pigments, dyes, etc. , Non-ionic surfactant of antistatic agent, cationic surfactant and the like.

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

As the (A) styrene resin, a (A-1) polystyrene resin having a reduced viscosity of 1.25 dl / g was used. The reduced viscosity referred to here was measured by the following method.

[Measurement of reduced viscosity (ηsp / C)]
A mixed solvent of 17.5 ml of methyl ethyl ketone and 17.5 ml of acetone is added to 1 g of a styrene resin, and the mixture is dissolved by shaking at a temperature of 25 ° C. for 2 hours. Methanol is added to precipitate the resin component, and the insoluble component is filtered and dried. The resin component obtained by the same operation was dissolved in toluene to prepare a sample solution having a polymer concentration of 0.4% (mass / volume). This sample solution and pure toluene were measured for the number of seconds of solution flowing down with a Ubbelohde viscometer at a constant temperature of 30 ° C., and calculated by the following formula.
ηsp / C = (t1 / t0-1) / C
t0: Number of seconds of pure toluene flowing down
t1: Number of seconds for sample solution to flow down
C: Polymer concentration

As the (B) brominated polyphenylene ether, (B-1) brominated polyphenylene ether (Emerald Innovation 1000 manufactured by Chemtura) was used.

Further, instead of (B) brominated polyphenylene ether, (B-2) decabromodiphenylethane (Saytex 8010 manufactured by Albemarle Corporation) was used.

[Preparation of flame-retardant styrene resin composition]
The above (A) styrene resin and (B) compound were blended in the ratios shown in Table 1 and premixed with a Henschel mixer (“FM20B” manufactured by Nippon Coke Industries, Ltd.). The premixed raw material was supplied to a twin-screw extruder (“TEM26SS” manufactured by Toshiba Machine Co., Ltd.) to form a strand, and after water cooling, it was guided to a pelletizer and pelletized. At this time, the resin temperature was set to the temperature shown in the table below and the supply amount was 30 kg / hour.

[transparency]
The transparency of the flame-retardant styrene resin composition of the present invention was evaluated by the degree of fogging and the total light transmittance. The obtained pellets were molded into test pieces having a length of 30 mm, a width of 30 mm, and a thickness of 2.0 mm using a press molding machine (“MP-2F” manufactured by Toyo Seiki Seisakusho Co., Ltd.). At this time, the hot plate temperature of the press molding machine was the temperature shown in the table, the preheating time was 3 minutes, the molding time was 2 minutes, and the molding pressure was 10 MPa. The haze and total light transmittance of the test piece were measured using a haze meter (NDH5000, manufactured by Nippon Denshoku Kogyo Co., Ltd.) based on JIS K 7136 and JIS K 7361. Those with a total light transmittance of 70% or more and a cloudiness of 10.0% or less were accepted.

[Total calorific value]
The obtained pellets were used in MCC (“MCC-3” manufactured by DEATAK), and the total calorific value [kJ / g] was measured based on ASTM D7309 Measurement A.

[Flame retardance]
A combustion test piece having a length of 127 mm, a width of 12.7 mm and a thickness of 1.5 mm was molded using an injection molding machine (“J100E-P” manufactured by Japan Steel Works, Ltd.). At this time, the cylinder temperature of the injection molding machine was 220 ° C., and the mold temperature was 45 ° C. Using the test piece, the flame retardancy was evaluated according to the UL94 vertical combustion test method. If this test method did not meet V-1, it was rejected.

The results are shown in Tables 1 and 2.

From Table 1, it can be seen that the molded product made of the flame-retardant styrene resin composition of the present invention has a high degree of flame retardancy while maintaining transparency.

Since the flame-retardant styrene resin composition of the present invention is excellent in transparency and flame retardancy, it is useful for general miscellaneous goods, housings for lighting devices, and the like.

Claims (3)

When (A) a styrene-based resin and (B) brominated polyphenylene ether represented by the following general formula (1) are contained, and (A) the styrene-based resin is 100 parts by mass, (B) brominated polyphenylene. The amount of ether compounded is 27 to 40 parts by mass, the total light transmittance is 70% or more and the cloudiness is 10.0% or less measured by a molded body having a thickness of 2.0 mm, and the degree of turbidity is 10.0% or less, and based on ASTM D7309 Resin A. A flame-retardant styrene resin composition having a measured total calorific value of 30.0 kJ / g or less.

(Here, n represents the degree of polymerization of integers 1 to 10. Further, X ₁ and X ₃ are independently bromine atoms of integers 1 to 5, and X ₂ represents bromine atoms of integers 0 to 4. ) The method for producing a flame-retardant styrene-based resin composition according to claim 1, wherein the resin temperature at the time of melt-kneading is 265 ° C. or higher. A molded product obtained by molding the flame-retardant styrene resin composition according to claim 1.