JPH09194657A - Flame-retardant polystyrene resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a halogen-free polystyrene resin improved in flame retardancy, impact resistance, etc. SOLUTION: A polystyrene resin (A) in an amount of 100 pts.wt. 5-50 pts.wt. mixture comprising a phosphate of melamine (B) and an epoxidized block copolymer (C) prepared by epoxidizing the unsaturated hydrocarbons originated in the residual conjugated diene compound of a block copolymer composed of at least one polymer block based on a vinylaromatic compound and at least one polymer block based on a conjugated diene in a molar ratio of 90:10 to 50:50 and having a ratio of the phenol novolac resin to the epoxidized block copolymer of 80:20 to 20:80 when E is used, 20:150 pts.wt. inorganic flame retardant (D) and optionally a phenol novolac resin is produced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polystyrene resin composition having good flame retardancy.

[0002]

2. Description of the Related Art Polystyrene, which is one of typical polystyrene resins, has many advantages such as low cost, transparency, good electrical insulation, good adhesion, and high rigidity. Therefore, it has a wide range of applications from food packaging materials to household products, soft media, household housings, office automation equipment and the like. ABS resin, which is another typical polystyrene resin, has many advantages such as low cost, high rigidity, good chemical resistance, good impact resistance, and good electric insulation. General equipment, electrical equipment, vehicles,
The uses of miscellaneous goods are even more widespread. As described above, polystyrene-based resins have various advantages, but polystyrene and ABS resins all have a common drawback that they are easily burned.

As a general method for flame-retarding a polystyrene resin, an organic flame retardant such as an organic halogen compound and a halogenated phosphoric acid ester, or a combination thereof with an inorganic flame retardant auxiliary such as antimony trioxide is used. It is known that it can be made flame-retardant. However, whichever method is adopted, the impact resistance and softening point of the resin composition are lowered, or the resin composition is extruded, and the allowable range of temperature control during injection molding is remarkably narrowed. Is decomposed to form a colored pellet or a molded product, or the decomposition causes the effect of imparting flame retardancy to be less than a satisfactory level.

Further, although the use of a halogen compound improves flame retardancy, it has a problem of environmental damage. The best flame-retardant method is to make the resin itself flame-retardant, and if the polystyrene-based resin can be made flame-retardant by a polymer alloy of polystyrene and halogen-free flame-retardant resin, it is the most effective method. Although preferable, flame retardation by such a method has not been found so far.

Further, in Japanese Patent Laid-Open No. 7-278384, an attempt has been made by using hydrogenated SBS modified with glycidyl methacrylate as an epoxy-modified resin. However, in such an epoxy-modified resin, the introduction amount of epoxy groups is small,
It has been difficult to obtain a resin composition having excellent impact resistance and flame retardancy.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polystyrene resin which is non-halogen and has improved flame retardancy and impact resistance.

[0007]

The present inventors have studied a method of simply blending various non-halogen flame retardants for flame retarding a polystyrene resin, but this method has an insufficient effect of improving flame retardancy. In addition, it has been found that a bleeding occurs, which causes defects such as deterioration in cold resistance and impact resistance. Therefore, as a result of further diligent study, by using melamine phosphate as a specific non-halogen flame retardant in a polystyrene resin together with an epoxidized diene block copolymer, impact resistance, cold resistance, etc. are hardly bleeding. It was found that the flame retardancy is improved without lowering the characteristics of

Further, when melamine phosphate, an epoxidized diene block copolymer and a phenol-nopohook resin are used in combination, bleeding does not occur at all, and characteristics such as cold resistance and heat resistance are not deteriorated and remarkably flame retardant is obtained. The inventors have found improvements and completed the present invention.

That is, the present invention relates to "(A) 100 parts by weight of polystyrene resin and (B) melamine phosphate.
(C) Unsaturated carbonization derived from a conjugated diene compound remaining in a block copolymer consisting of a polymer block mainly containing at least one vinyl aromatic compound and a polymer block mainly containing at least one conjugated diene compound 80:20 with an epoxidized block copolymer obtained by epoxidizing hydrogen
5 to 50 parts by weight of the mixture in the ratio of 20:80, and (D)
A flame-retardant polystyrene-based resin composition characterized by containing 20 to 150 parts by weight of an inorganic flame retardant "," (A)
Based on 100 parts by weight of polystyrene resin, (B) melamine phosphate and (C) at least one vinyl aromatic compound-based polymer block and at least one conjugated diene compound-based polymer block The ratio of the block copolymer consisting of the remaining conjugated diene compound and the epoxidized block copolymer obtained by epoxidizing unsaturated hydrocarbon derived from the conjugated diene compound is 90:10 to 50:50, ) The epoxidized block copolymer is 8
5 to 50 parts by weight of a mixture having a ratio of 0:20 to 20:80, (D) 20 to 150 parts by weight of an inorganic flame retardant, and (E) a flame retardant flame-retardant resin characterized by being blended. Polystyrene resin composition "and" method for producing the same ".

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The polystyrene resin used as the component (A) of the present invention is not particularly limited and is commercially available. Examples of polystyrene-based resins include styrene and α-substituted styrenes such as α-methylstyrene, styrene-derivatized polymers such as vinyltoluene, and monomers mainly containing these monomers and copolymerizable with them. Polymers such as acrylonitrile, butadiene, isoprene, acrylic rubber, and the like are copolymerized.

Melamine phosphate which is the component (B) of the present invention has an excellent compatibility with the polystyrene resin and is an important component which imparts a high degree of flame retardancy to the polystyrene resin. The melamine phosphate which is the component (B) of the present invention is not particularly limited, and a commercially available product may be used as it is.
Examples include PP-A [Sanwa Chemical Co., Ltd.] and P-7202 [Sanwa Chemical Co., Ltd.].

In the epoxidized diene block copolymer which is the component (C) of the present invention, the epoxy group reacts with melamine phosphate, and the resulting compound has affinity for polystyrene resin and melamine phosphate. Since it has a component that has, it acts as a compatibilizing agent for polystyrene resin and melamine phosphate, prevents bleeding of melamine phosphate, and has the function of further dispersing melamine phosphate in polystyrene resin in a very important manner. It is an ingredient. The epoxidized diene-based block copolymer used in the present invention is a commercially available styrene-butadiene-based block copolymer, styrene-isoprene-based block copolymer, and further, the block copolymer is partially hydrogenated. Unsaturated hydrocarbons derived from conjugated diene components that remain styrene-ethylene / butylene-styrene block copolymers, styrene-ethylene / propylene-styrene block copolymers, etc. as organic peracids such as peracetic acid, or organic peroxides. It is an epoxidized product.

The oxirane oxygen concentration of the epoxidized diene block copolymer used in the present invention is preferably 0.5 to 5.0% by weight, and is compounded with other compounding agents (B) and (E). There is an appropriate amount of epoxy groups introduced depending on the ratio. However, if the introduction amount of the epoxy group in the epoxidized diene-based block copolymer is lower than this, the melamine phosphate is easily bled, and if it is increased, the fluidity of the resin composition decreases.

The inorganic flame retardant which is the component (D) of the present invention is not particularly limited and is commercially available.
Examples thereof include magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like.

The phenol novolak resin used as the component (E) of the present invention is not particularly limited and is commercially available. For example, phenol and formalin are mixed with formaldehyde / phenol in moles. The ratio is
0.5-1. Charge into a reaction kettle at a mixing ratio that results in O, add catalysts such as oxalic acid, hydrochloric acid, sulfuric acid, and toluenesulphonic acid, then heat and reflux for an appropriate period of time, then remove the separated water Therefore, it can be obtained by vacuum dehydration or stationary dehydration, and further removing residual water and unreacted phenols. The co-condensed phenol resin obtained by using these resins or a plurality of raw material components may be used alone or in combination of two or more kinds.

The polystyrene resin composition of the present invention is
(A) component polyolefin resin, (B) component melamine phosphate, (C) component epoxidized diene block copolymer, and / or (E) component phenol novolac resin, (D) component Inorganic flame retardant is added all at once, and it is heated at 150-250 ° C for 10 to 10 minutes with a pressure kneader or Banbury mixer.
Melt kneading for 30 minutes, or (B) component melamine phosphate and (c) component epoxidized diene block copolymer and / or (E) component phenol novolak resin in advance 100 ~ 250 ℃, After melt-kneading for 10 to 30 minutes,
It can be obtained by adding a polystyrene resin as component (A) and then melt-kneading.The latter is melamine phosphate as component (B) and epoxidized diene block copolymer as component (C) and / or Alternatively, the (E) component phenol-novolak resin is mixed uniformly, which is preferable. In the polystyrene resin composition of the present invention, 100 parts by weight of the polystyrene resin as the component (A) and melamine phosphate (C) as the component (B)
Component epoxidized diene block copolymer and / or
Add a mixture of (E) component and phenol-pololac resin to 5
50 parts by weight of component (C), an inorganic flame retardant, must be added in the range of 20 to 150 parts by weight. Further, the melamine phosphate as the component (B) and the epoxidized diene block copolymer as the component (C) in a ratio of 80:20 to 20:80 are more preferably used.

If the mixture of the melamine phosphate as the component (B), the epoxidized diene block copolymer as the component (C) and / or the phenol novolak resin as the component (E) is 5 parts by weight or less, the flame retardancy is reduced. If the amount is 50 parts by weight or more, various advantages of the polystyrene-based resin are deteriorated.

The proportion of melamine phosphate in the mixture of the melamine phosphate as the component (B), the epoxidized diene block copolymer as the component (C) and / or the phenol novolak resin as the component (E) is 80% by weight. If it exceeds 20%, the effect of adding the epoxidized diene block copolymer as the component (C) and / or the phenol novolak resin as the component (E) tends to be ineffective, and if it is less than 20% by weight, the flame retardancy decreases. Become a trend.

When the amount of the inorganic flame retardant as the component (D) is 20 parts by weight or less, the effect of improving the flame retardancy is insufficient, and when it exceeds 150 parts by weight, mechanical properties and the like are remarkably deteriorated. As described above, the polystyrene resin composition of the present invention has an effect of improving flame retardancy without causing almost any deterioration in the properties of the polystyrene resin as the component (A). Melamine phosphate, which has phosphorus and nitrogen elements in and is excellent in flame retardance, has good compatibility with polystyrene-based resins, and by using melamine phosphate and a phenol novolac resin together, a coating with melamine phosphate is provided. It is considered that this is because a synergistic effect of two types of flame retardant effects and shell formation at the time of formation and combustion by phenol phenolic resin is obtained.

When melamine phosphate and an epoxidized diene block copolymer are used in combination, the compound formed by the reaction between melamine phosphate and an epoxy group has an affinity for both melamine phosphate and polystyrene resin in the molecule. It is considered that the melamine phosphate acts as a compatibilizer, prevents bleeding of the melamine phosphate, and further allows the melamine phosphate to be microscopically dispersed in the polystyrene resin. Further, it is considered that the combined use of melamine phosphate, phenol novolac resin and epoxy modified resin enabled the synergistic effect of flame retardancy and melamine phosphate to be micro-dispersed in polystyrene resin.

The polystyrene resin composition of the present invention comprises
Furthermore, other compounding agents such as talc, depending on the use and purpose,
Inorganic fillers such as mica, calcium carbonate and wollastonite, coupling agents or reinforcing agents such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, antistatic agent, antistatic agent, stabilizer, pigment, mold release It is possible to add agents and the like, and further it is possible to add impact resistance improvers such as various elastomers (polyolefin type, polyester type, polyamide type, polyurethane type) and the like. The polystyrene-based resin composition of the present invention can be easily processed into a molded product by a processing method used for ordinary thermoplastic resin molded products, such as injection molding or extrusion molding.

<Example> The present invention will be described below with reference to examples, but this is merely an example and the present invention is not limited thereto.

Tensile test: ASTM-D638 Izod impact test: JIS K6871 Combustion test: Underwriters Laboratories safety standard UL94 (○: Burning time is within 10 seconds, Δ: Burning for 10 seconds or more, ×: Burning, appearance (visual judgment) , *: No bleeding, ◯: almost no, Δ: little, x: yes).

(Example) As the component (A), polystyrene [PS: Daicel Styro-produced by Daicel Chemical Industries Ltd.]
Le MIPS R71] or ABS resin [ABS: Diapet ABS RSE-7 manufactured by Mitsubishi Rayon Co., Ltd.], hydrogenated product of styrene-butadiene block copolymer [S
EBS: Asahi Kasei Tuftec H1052], (B)
Melamine phosphate [MPP-A: Sanwa Chemical Co., Ltd.] as a component, magnesium hydroxide and aluminum hydroxide as a component (D), and phenol-nopolak resin [PN: Sumitomo Dures] as a component (E). Made by PR-
51470] as the component (C), and an epoxidized styrene-butadiene block copolymer [ESBS; TR200
0 (Japan Synthetic Rubber) epoxidized with peracetic acid, oxirane oxygen concentration 3.1% by weight], hydrogenated product of epoxidized styrene-butadiene block copolymer [ESEB]
S: Tough tech H1052 (Asahi Kasei) epoxidized with peracetic acid, oxirane oxygen concentration 0.7% by weight], hydrogenated product of epoxidized styrene-isoprene block copolymer [ESEPS; styrene with a hydrogenation rate of 25%] Isoprene block copolymer (styrene / rubber weight ratio = 3
0/70) epoxidized with peracetic acid, oxirane oxygen concentration 3.5% by weight] was used.

The formulations and the evaluation results are shown in Tables 1 and 2.

Comparative Example As the component (A), [PS: Daicel Styrol MIPS manufactured by Daicel Chemical Industries, Ltd.]
R71] or ABS resin [ABS: Mitsubishi Rayon Co., Ltd.
Diapet ABS RSE-7], hydrogenated styrene-butadiene copolymer [SEBS: Asahi Kasei Corp.
Tuftec H1052], (B) component melamine phosphate [MPP-A: Sanwa Chemical Co., Ltd.], (D) component magnesium hydroxide and aluminum hydroxide, and (E) component phenol. I-Lunovolac resin [P
N: Sumitomo Deyureze Co., Ltd. PR-51470], (C)
As components, epoxidized styrene-butadiene block copolymer [ESBS; TR2000 (Japan Synthetic Rubber) epoxidized with peracetic acid, oxirane oxygen concentration 3.
1% by weight], hydrogenated product of styrene-butadiene block copolymer [ESEBS; Teftec H1052 (Asahi Kasei) epoxidized with peracetic acid, oxirane oxygen concentration 0.7% by weight], epoxy modified SEBS [GMA-S
EBS: Asahi Kasei Corporation Tuftec Z-514] was used. The blending and evaluation results are shown in Tables 3 and 4.
(Below margin) Table 1 Example 1 2 3 4 5 6 formulation (parts by weight) PS 100 100 100 100 100 ABS 100 100 MPP-A 10 20 15 15 15 20 20 PN 5 10 5 ESBS 5 10 10 5 ESEBS 10 ESEPS 10 water Magnesium oxide 80 80 80 Aluminum hydroxide 80 80 80 Characteristic tensile strength (Kg / cm2) 240 230 230 235 370 390 Tensile elongation (%) 40 45 40 40 55 50 Izod test 10 13 10 11 40 35 (Kg · cm / cm) UL94 1st ignition ○ ○ ○ ○ ○ ○ 2nd ignition △ ○ ○ △ ○ ○ Melt droplet No No No No No No Molded appearance * * * * * * (the following margin) Table 2 Example 7 8 9 10 Composition (parts by weight) SEBS 100 100 100 100 100 MPP-A 15 10 10 20 PN 10 5 5 ESBS 10 5 ESEBS 10 ESEPS 10 Magnesium hydroxide 80 Aluminum hydroxide 80 80 80 Characteristic tensile strength (Kg / cm2) 110 100 95 110 Tensile elongation (%) 750 800 720 790 Izod test N. BN. BN. BN. B (Kg · cm / cm) UL94 First ignition ○ ○ ○ ○ Second ignition △ △ △ △ Molten droplets No No No No Molded appearance * * * * (margin) Table 3 Comparative Example 1 2 3 4 5 6 Composition (parts by weight) PS 100 100 100 100 100 ABS 100 100 MPP-A 10 10 60 3 30 30 PN 30 GMA-SEBS 10 ESBS magnesium hydroxide 80 80 aluminum hydroxide 80 80 80 80 characteristic tensile strength (Kg / cm2) 250 410 150 400 110 110 240 Tensile elongation (%) 30 50 20 50 20 20 30 Izod test 5 25 4 27 5 6 (Kg · cm / cm) UL94 1st ignition △ △ ○ △ ○ ○ 2nd ignition × × ○ × ○ △ Melted droplet Yes Yes No No Yes No No Molded appearance * * △ ○ △ * (Margins below) (Below margin)

[0027]

As is clear from the table, the flame-retardant polystyrene resin composition of the present invention has improved impact resistance as compared with SEBS modified with glycidyl methacrylate while maintaining the characteristics of polystyrene resin. However, it is a novel material with significantly improved flame retardancy, and can be easily processed into molded products by the processing methods used for ordinary thermoplastic molding materials, such as injection molding and extrusion molding, and it has excellent mechanical strength. The product has an excellent balance of physical properties such as moldability. (Below margin)

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // (C08L 25/04 63:08 61:06)

Claims (6)

[Claims] 1. A polymer block mainly comprising (B) melamine phosphate and (C) at least one vinyl aromatic compound, and at least one conjugated diene, relative to 100 parts by weight of a polystyrene resin (A). Mixture 5 of the ratio of 80:20 to 20:80 with the epoxidized block copolymer obtained by epoxidizing the unsaturated hydrocarbon derived from the conjugated diene compound remaining in the block copolymer composed of the polymer block containing the compound as a main component. To 50 parts by weight, and (D) inorganic flame retardant 20 to 150
A flame-retardant polystyrene-based resin composition, characterized by being mixed in parts by weight. 2. A polymer block mainly composed of (B) melamine phosphate and (C) at least one vinyl aromatic compound, and at least one conjugated diene, relative to 100 parts by weight of polystyrene resin (A). The ratio of the block copolymer consisting of the polymer block containing the compound to the epoxidized block copolymer obtained by epoxidizing the residual conjugated diene compound-derived unsaturated hydrocarbon is 90:10 to 50:50 (E )
5 to 50 parts by weight of a mixture of a phenolic novolac resin and (C) the epoxidized block copolymer in a ratio of 80:20 to 20:80, and (D) 20 to 150 parts by weight of an inorganic flame retardant and (E ) A flame-retardant polystyrene-based resin composition comprising a pheno-novolak resin. 3. The (A) polystyrene resin is polystyrene, a styrene-butadiene copolymer, an acrylonitrile-butadiene-styrene copolymer, an acrylonitrile-acrylic rubber-styrene copolymer, or a poly (styrene-butadiene) copolymer. The flame-retardant polystyrene resin composition according to claim 1 or 2, which is at least one resin selected from hydrogenated products of poly (styrene-butadiene) copolymer. 4. The flame-retardant polystyrene resin composition according to claim 1, wherein the oxirane oxygen concentration of the (C) epoxidized block copolymer is 0.5 to 5% by weight. 5. The method according to claim 1 or 2, wherein (B) melamine phosphate and (c) an epoxidized diene block copolymer are melt-kneaded in advance, then blended with a polystyrene resin, and further melt-kneaded. A method for producing a flammable polystyrene resin composition. 6. (B) Melamine phosphate, (E) phenol novolac resin and (C) epoxidized diene block copolymer are melt-kneaded in advance, then blended with polystyrene resin, and further melt-kneaded The method for producing the flame-retardant polystyrene resin composition according to claim 1.