JP2837738B2 - Light-resistant flame-retardant resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a styrene resin composition having excellent light resistance, flame retardancy, good impact resistance, and excellent heat stability during molding. It is.

[Problems to be solved by conventional technology and invention]

Styrene resin is inexpensive and has excellent impact resistance, heat resistance,
Since it has many properties such as mechanical properties, electrical properties, and moldability, it is widely used in household electric appliances, office equipment, household goods, and the like. However, styrene resins are flammable, and various regulations regarding flame retardancy, such as UL standards, have been strengthened and are subject to many restrictions on use.

Styrene-based resins are made flame-retardant by adding compounds containing halogen, phosphorus, etc., or flame-retardant auxiliaries such as antimony trioxide. Although the desired flame retardancy can be obtained by blending, it often has a bad influence on other physical properties. With the spread of large molded products such as large television housings and computer housings in recent years, in addition to flame retardancy and impact resistance, excellent light resistance is also strongly required to reduce discoloration due to light such as fluorescent lamps. ing.

Conventionally, Japanese Patent Application Laid-Open No. 50-9645 discloses that a flame-retardant thermoplastic resin composition using a diimide compound is disclosed, and a flame-retardant effect is described, but one that satisfies impact strength is disclosed. There were drawbacks that could not be obtained. Furthermore, when a diimide compound is simply used as a thermoplastic resin, the dispersibility is poor, the impact resistance is reduced, and in order to obtain the required impact strength, the rubber content must be increased, and therefore the thermal stability In fact, it has been very difficult to obtain a flame-retardant thermoplastic resin composition having an excellent quality balance due to impaired fluidity, rigidity and flame retardancy.

[Means for solving the problem]

In view of such circumstances, the present inventors have conducted intensive studies to obtain a styrene-based resin composition having excellent light resistance, flame retardancy, and good impact resistance, and having excellent thermal stability during formation.
Rubber-modified polystyrene resin with a specific amount of rubber,
A halogen-containing compound having a specific structure and 95% by weight or more of the particles is 16μ or less, a dispersant having a melting point or softening point of 200 ° C or less, a benzotriazole-based ultraviolet absorber, a sterically hindered amine-based light stabilizer and The present invention has been accomplished by finding that it can be achieved by blending titanium oxide.

That is, the present invention provides (A) a rubbery polymer having a rubber amount of 3 to
(B) The following formula is added to 100 parts by weight of the rubber-modified polystyrene resin which is 18% by weight. (X is bromine or chlorine, a and b are natural numbers of 1 to 4), and 6 to 20 parts by weight of a halogen-containing compound in which 95% by weight or more of the particles are 16 μ or less, (C) melting point or Dispersant having a softening point of 200 ° C or less 0.1 to 3.
0 parts by weight, and 0.1 to 3.0 parts by weight of (D) a benzotriazole-based ultraviolet absorber, 0.05 to 3.0 parts by weight of a sterically hindered amine-based light stabilizer, and 0.5 to 10 parts by weight of titanium oxide. It is about things.

 Hereinafter, the present invention will be described in detail.

Rubber-modified polystyrene resin (A) used in the present invention
Dissolves the rubbery polymer in the monovinyl aromatic monomer,
It can be produced by ordinary bulk polymerization or bulk-suspension polymerization. Monovinyl aromatic monomers include styrene,
α-substituted styrenes such as α-methylstyrene; vinyl toluene, m-chlorostyrene, p-chlorostyrene, p-
Nuclear-substituted styrenes such as methylstyrene may be mentioned, and one or more of these may be used. Styrene is most preferred. Examples of the rubbery polymer include natural rubber, polybutadiene, butadiene-styrene copolymer, and butadiene-
Examples include acrylonitrile copolymer, polychloroprene, acrylic rubber, ethylene-propylene rubber, ethylene-propylene-diene monomer rubber, and ethylene-vinyl acetate copolymer. Polybutadiene and butadiene-styrene copolymer are preferred.

The rubber content in the rubber-modified polyethylene resin (A) used in the present invention needs to be 3 to 18% by weight. If the rubber content is less than 3% by weight, the impact strength is reduced, and if it is more than 18% by weight, characteristics such as flame retardancy, light resistance, fluidity, rigidity and heat resistance are undesirably reduced.

The halogen-containing compound (R) used in the present invention has the following formula: (X is bromine or chlorine, a and b are natural numbers of 1 to 4). The amount of the halogen-containing compound is 6 parts by weight per 100 parts by weight of the rubber-modified polystyrene resin (A).
~ 20 parts by weight are required. If the amount is less than 6 parts by weight, the required flame retardancy cannot be obtained. If the amount exceeds 20 parts by weight, not only is it economically disadvantageous, but also the impact resistance, especially the falling weight impact strength of practical impact strength, is high. Decrease in width.

Further, regarding the particle size of the halogen-containing compound,
It is necessary that 95% by weight or more is a fine solid of 16μ or less, and preferably 98% by weight or more. If 95% by weight or more of the particles is not 16 μm or less, the impact resistance is reduced, and the screen of the extruder is clogged with a mesh during compounding, and the mass production is difficult due to venting up.

The dispersant (C) having a melting point or softening point of 200 ° C. or less used in the present invention is used in an amount of 0.1 to 3 parts by weight per 100 parts by weight of the rubber-modified polystyrene resin (A). By blending the halogen-containing compound (B) and a dispersant (C) having a melting point or softening point of 200 ° C. or less with the rubber-modified polystyrene resin (A), the impact resistance can be greatly improved, especially the falling weight impact strength Has greatly improved, and the flame retardancy has also improved. When the blending amount of the dispersant having a melting point or softening point of 200 ° C or less is less than 0.1 part by weight, the effect of improving the impact resistance is small and the flame retardancy is reduced,
On the other hand, if it is more than 3 parts by weight, it tends to burn, and a large amount of flame retardant is required, which is not economically preferable. On the other hand, a dispersant having a melting point or softening point of 200 ° C. or higher results in poor wettability. Examples of the dispersant (C) used in the present invention include calcium stearate, calcium laurate, calcium ricinoleate, zinc stearate, zinc laurate, zinc ricinoleate, tin stearate, magnesium stearate, ethylene bisstearamide, low molecular weight Polyethylene (110P manufactured by Mitsui Petrochemical Co., Ltd.) and the like. Of these, ethylene bis stearamide, calcium stearate,
Low molecular weight polyethylene (manufactured by Mitsui Petrochemical, 110P) is preferred.

In the present invention, the rubber-modified polystyrene resin (A)
Benzotriazole UV absorber per 100 parts by weight
0.1 to 3 parts by weight, sterically hindered amine light stabilizer 0.05 to 3
Parts by weight and 0.5 to 10 parts by weight of titanium oxide. The benzotriazole-based ultraviolet absorber was added to 100 parts by weight of the rubber-modified polystyrene-based resin (A) in an amount of 0.1%.
When the amount is less than 1 part by weight, the light resistance effect is small, and when it is more than 3.0 parts by weight, heat resistance is reduced. When the amount of the sterically hindered amine light stabilizer is less than 0.05 part by weight, the effect of light resistance is small, and when the amount is more than 3.0 parts by weight, heat resistance is reduced.

Furthermore, when titanium oxide is less than 0.5 parts by weight,
If the light resistance effect is small, and if it is more than 10 parts by weight, the impact resistance is undesirably reduced.

As the benzotriazole-based ultraviolet absorber to be used, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H -Benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-
Butyl-5-methyl-2-hydroxyphenyl) -5
Chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, methyl-3- [3-t-butyl-5- (2H-benzotriazol-2-yne) -4-hydroxyphenyl]
There are propionate-polyethylene glycol condensate, hydroxyphenylbenzotriazole derivative and the like.

Examples of the sterically hindered amine light stabilizer used include dimethyl succinate 1- (2-hydroxyethyl).
-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2, 4-diyne II (2,
2,6,6-tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}], N, N'-bis (3-aminopropyl)
Ethylenediamine-2,4-bis [N-butyl-N- (1,
2,2,6,6-pentamethyl-4piperidyl) amino] -6
-Chloro-1,3,5-triazine condensate, bis (2,2,6,6
-Ratramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidinyl) succinate, 2- (3,5-di-t-butyl-4-hydroxybenzyl)- Bis (1,2,2,2-n-butylmalonate)
6,6-pentamethyl-4-piperidyl) and the like.

Thus, the rubber-modified polystyrene resin (A)
100 parts by weight of the halogen-containing compound (B) 6 to 20
Parts by weight, melting point or softening point 200 ° C or less Dispersant (C) 0.1 to
Only 3 parts by weight of a benzotriazole ultraviolet absorber, a sterically hindered amine light stabilizer and titanium oxide (D) are combined, and a styrene resin having excellent light resistance, good flame retardancy, and excellent heat stability during molding. A resin composition is obtained, and the present invention is not achieved even if any one is missing.

The method for producing a light-resistant flame-retardant resin composition of the present invention comprises a dispersant having a halogen-containing compound (B) of 6 to 20 parts by weight, a melting point or a softening point of 200 ° C. or less per 100 parts by weight of a rubber-modified polystyrene resin (A). C) 0.1 to 3 parts by weight, 0.1 to 0.3 parts by weight of a benzotriazole type ultraviolet absorber, 0.05 to 3.0 parts by weight of a sterically hindered amine light stabilizer and 0.5 to 10 parts by weight of titanium oxide. The compounding method is not particularly limited. For example, a rubber-modified polystyrene resin (A), a halogen-containing compound (B), a dispersant (C) having a melting point or a softening point of 200 ° C. or less, a benzotriazole-based ultraviolet absorber, There is a method of mixing a hindered amine-based light stabilizer and titanium oxide with a drum blender and kneading using a twin-screw extruder,
There is also a method using a Dumbler mixer, a super mixer, a Banbury mixer, a kneader, a roll, a single screw extruder, or the like.

Various additives can be added to the composition of the present invention, if necessary, as long as the object of the present invention is not impaired. Various additives include a plasticizer, a lubricant, a flame retardant aid, a stabilizer, a filler, a reinforcing agent, and a colorant.

〔The invention's effect〕

The light-resistant flame-retardant resin composition of the present invention is a styrene-based resin composition having excellent light resistance, flame retardancy and good impact resistance, and excellent heat stability during molding. It is extremely useful industrially as a housing material for equipment.

〔Example〕

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but this does not limit the scope of the present invention.

The evaluation of the highly light-resistant flame-retardant resin composition was performed by the following method. The pellets were used for the melt flow rate, and the injection molding test pieces were used for other tests.

・ Izod impact strength; ASTM D 256 Specimen thickness 6.4mm, with notch ・ Tensile strength, elongation: ASTM D 638 ・ Melt flow rate; ISO R 1133 temperature 200 ° C, load 5kg ・ Heating deformation temperature: ASTM D 648 test Specimen thickness: 6.4mm, without annealing Bending stress: 18.6kg / cm ² · Light resistance: Measure the degree of discoloration of the test specimen after 300 hours with a Canon Arc Weatherometer using a color difference meter and express it as the difference from the unexposed sample. .

-Flame retardancy; UL-94 test piece thickness 1/12 inch, V-0 rank is judged.

-Drop weight impact strength: Drop a missile (R = 3/4 inch) on a flat molded product of 150 mm square, 3 mm thick, single pin gate.
By changing the weight of the missile and the drop distance of the missile (the distance from the tip of the missile to the surface of the molded product), calculate the breaking energy at which the molded product cracks.

-Thermal stability test; Toshiba Machine IS80-A, cylinder temperature 23
After molding at 0 ° C. and a mold temperature of 60 ° C. for a residence time of 20 minutes, the burn state of the third shot color chip (90 mm × 50 mm × 2.5 mm thickness) is compared and observed.

Rubber weight; the resin composition at 200 ° C. in compression, the film in the thin film infrared spectrophotometer (Hitachi: EPI, G-3) at, 1601 cm ^-1, the absorption band of 967 cm ^-1 Is measured, and the amount of rubber is measured using a calibration curve prepared in advance.

(In the case of rubber-modified polystyrene resin) The rubber-modified polystyrene resin used in Examples and Comparative Examples was prepared by adding 10 parts of ethylbenzene to 100 parts of a solution in which polybutadiene was dissolved in a styrene monomer to prepare a polymerization raw material liquid. The raw material liquid was continuously fed into a continuous three-stage polymerization machine to perform polymerization. Each polymerization machine has a capacity of 1.2 and is equipped with stirring blades. The polymerization temperature was varied between 120 and 170 ° C. After the polymerization at the outlet of the final polymerization machine until the solid content became 80%, it was sent to a devolatilizer under heating vacuum to remove unreacted styrene monomer and ethylbenzene. The strand is pulled from the die, cooled with water, and cut into pellets. The content of the rubbery substance in the pellet was measured to obtain a rubber-modified polystyrene resin (A-1) having a rubber content of 10%. A-2 to A-5 were polymerized in a similar manner. Table 1 shows the rubber-modified polystyrenes A-1 to A-5.

(Halogen-containing compound) Table 2 shows properties of various halogen-containing compounds used in Examples and Comparative Examples.

(Dispersant) As a dispersant, ethylene bis stearoamide, calcium stearate, and low molecular weight polyethylene (110P, manufactured by Mitsui Petrochemical Co., Ltd.) were used.

(Benzotriazole-based ultraviolet absorber) As the benzotriazole-based ultraviolet absorber, those shown in Table 3 below were used.

(Sterically hindered amine light stabilizer) As the sterically hindered amine light stabilizer, those shown in Table 4 below were used.

(Titanium oxide) As titanium oxide, the trade name RTC of ICI (USA)
-30 was used.

Example 1 A rubber-modified polystyrene resin (A-1), a halogen-containing compound (B-1), and others were mixed in a mixing ratio shown below in a drum blender, and then heated at 220 ° C. using a twin screw extruder with a 35 m / mφ bend. It was kneaded and pelletized.

Rubber-modified polyethylene resin (A-1) 100 parts by weight Halogen-containing compound (B-1) 17 parts by weight Antimony trioxide 5 parts by weight Ethylene bisstearamide 0.5 parts by weight Benzotriazole ultraviolet absorber (C-1) 1.0 parts by weight Part Sterically hindered amine light stabilizer (D-1) 0.5 part by weight Titanium oxide 1.0 part by weight The obtained pellets have a cylinder temperature of 220 ° C and a mold temperature of 6
Injection molding was performed at 0 ° C., and various physical properties were measured. The results are shown in Table 4 (1).

Examples 2 to 5 and Comparative Examples 1 to 14 Rubber-modified polystyrene resin, halogen-containing compound, dispersant, benzotriazole-based UV absorber, sterically hindered amine light stabilizer, and titanium oxide are shown in Table 4 (1) and (2). ,
A resin composition was produced in the same manner as in Example 1 except that the mixing ratio shown in (3) was used. The results are shown in Tables 4 (1), (2) and (3).

Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08K 5:20 5: 3475 5:17 3:22) (58) Investigated field (Int.Cl. ⁶ , DB name) C08L 51/04 C08K 5/3417 C08K 5/098 C08K 5/20 C08K 5/3475 C08K 5/17 C08K 3/22 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] (A) 100 parts by weight of a rubber-modified polystyrene resin having a rubber content of 3 to 18% by weight of a rubbery polymer; (X is bromine or chlorine, a and b are natural numbers of 1 to 4), and 6 to 20 parts by weight of a halogen-containing compound in which 95% by weight or more of the particles are 16 μ or less, (C) melting point or Dispersant having a softening point of 200 ° C. or less 0.1 to 3.0
A light-resistant flame-retardant resin composition comprising 0.1 to 3.0 parts by weight of (B) a benzotriazole-based UV absorber, 0.05 to 3.0 parts by weight of a sterically hindered amine-based light stabilizer and 0.5 to 10 parts by weight of titanium oxide.