KR100557772B1 - Flame Retardant Syndiotactic Polystyrene Composition having Improved Impact Strength - Google Patents

Abstract

Syndiotactic polystyrene resin composition having excellent flame retardancy and mechanical properties of the present invention comprises (A) 46 to 94 parts by weight of syndiotactic polystyrene (sPS); (B) 1 to 20 parts by weight of hydrogenated styrene / butadiene / styrene block copolymer (hydrogenated styrene / butadiene / styrene block copolymer: SEBS); (C) 1 to 10 parts by weight of hydrogenated styrene / butadiene / styrene-maleic anhydride copolymer (hydrogenated styrene / butadiene / styrene-maleic anhydride copolymer: SEBS-MA); (D) 20 to 48 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); (F) 0.5 to 10 parts by weight of a diamine compound; (G) 5 to 30 parts by weight of a phosphate flame retardant; And optionally (H) 5 to 40 parts by weight of glass fiber.

Description

Flame Retardant Syndiotactic Polystyrene Composition having Improved Impact Strength

Field of invention

The present invention relates to a syndiotactic polystyrene resin composition excellent in flame retardancy. More specifically, the present invention is excellent in mechanical properties by applying a non-halogen-based flame retardant and polyphenylene oxide (PPO) to a composition comprising a syndiotactic polystyrene with enhanced impact resistance, particularly without significantly lowering the impact strength It relates to an impact-resistant syndiotactic polystyrene resin composition excellent in flame retardancy.

Background of the Invention

Syndiotactic polystyrene (sPS), a polymer having a crystalline structure, has a high melting point (Tm) of about 270 ° C., and is of interest because of its excellent mechanical properties including thermal stability and rigidity. However, their use has been extremely limited due to their low impact resistance. In order to solve this problem, many studies have been conducted on the technology of improving the impact strength by introducing a rubber-based impact modifier and various compatibilizers (US Pat. Nos. 5,777,028, 5,760,105, 5,654,365, 5,543,462 and 5). 5,270,353 5,391,603 and 5,352,727).

The conventional techniques are phase separation by improving the interfacial properties between rigid syndiotactic polystyrene and rubber components by using a rubber component as a compatibilizer and a method of reinforcing elasticity through simple kneading of syndiotactic polystyrene and rubber components. Can be categorized in two ways to prevent it from happening. Of these, the latter method is more preferable for workability and reproducibility of physical properties. However, in the latter case, since the mechanism of applying the compatibilizer is limited to improving the polarity of the rubber component, the impact strength has been limited.

The present inventors apply syndiotactic polystyrene-maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) as a compatibilizer between syndiotactic polystyrene (sPS) and rubber components and diamine By adding a compound, it is possible to impart polarity to both syndiotactic polystyrene and rubber components, improve interfacial properties, and develop a syndiotactic polystyrene resin composition having excellent impact resistance. Has been applied for a patent.

On the other hand, Idemitsu Co., Ltd. has launched a commercially available flame retardant compound filled with glass fiber in a syndiotactic polystyrene resin composition with reinforced impact properties. Due to human hazards and environmental pollution, it has been required to supplement product characteristics.

Flame retardants mainly used in resin compositions include halogenated flame retardants and non-halogen flame retardants represented by bromine and chlorine compounds. Halogen-based flame retardants have excellent flame retardancy and strong chemical resistance, but have poor weather resistance and can cause mold corrosion problems due to the generation of hydrogen halide due to the deterioration of thermal stability during high temperature molding. Especially, high melting point resin such as syndiotactic polystyrene In the case of molding process, there is a high risk of side effects, and there is a disadvantage that causes a large amount of harmful gas generated by forced combustion. On the other hand, non-halogen phosphate ester flame retardant is advantageous in terms of environment because it generates little combustion gas because plasticization occurs additionally, dehydration reaction is promoted, and char is generated by char.

Accordingly, the present inventors apply a non-halogen phosphate ester flame retardant to a resin composition containing syndiotactic polystyrene having improved impact resistance to solve various problems when applying a halogen compound as described above, and polyphenylene oxide. By adjusting and applying the content of (PPO) according to the use of the resin composition, the mechanical properties are improved and the impact resistance is equivalent to the conventional resin compositions to develop a syndiotactic polystyrene resin composition that can maintain flame retardancy.

An object of the present invention is to provide a syndiotactic polystyrene resin composition that is environmentally friendly and sufficiently flame retardant by applying a non-halogen phosphate-based flame retardant to a resin composition containing a syndiotactic polystyrene excellent in impact resistance will be.

Another object of the present invention is to adjust the content of the phosphate ester flame retardant and polyphenylene oxide (PPO) to the composition containing syndiotactic polystyrene, mechanical properties and impact resistance is equivalent to the conventional resin composition and sufficient flame resistance It is to provide a syndiotactic polystyrene resin composition that is maintained.

Still another object of the present invention is to provide a syndiotactic polystyrene resin composition which can be used in various fields in combination with physical properties such as flame retardancy, mechanical strength, impact strength, and the like.

The above and other objects of the present invention can be achieved by the present invention described below. Hereinafter, the content of the present invention will be described in detail.

Impact resistant syndiotactic polystyrene resin composition excellent in flame retardancy of the present invention comprises (A) 46 to 94 parts by weight of syndiotactic polystyrene (sPS); (B) 1 to 20 parts by weight of hydrogenated styrene / butadiene / styrene block copolymer (SEBS); (C) 1 to 10 parts by weight of hydrogenated styrene / butadiene / styrene-maleic anhydride copolymer (SEBS-MA); (D) 20 to 48 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); (F) 0.5 to 10 parts by weight of the diamine compound; (G) 5 to 30 parts by weight of a phosphate ester flame retardant; And optionally (H) 5 to 40 parts by weight of glass fibers.

Syndiotactic polystyrene resin composition of the present invention is syndiotactic polystyrene maleic anhydride (sPS-MA) and hydrogenated styrene / butadiene / styrene anhydride as a compatibilizer for impact reinforcement in syndiotactic polystyrene (sPS) as a main component. Maleic acid (SEBS-MA) is applied and polyphenylene oxide (PPO) is added to increase the compatibility of the rubber component with syndiotactic polystyrene.

In addition, a chemical reaction through coupling reaction between syndiotactic polystyrene-maleic anhydride (sPS-MA), a compatibilizer treated with maleic anhydride, and hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA) having polarity A bond is made and by adding a diamine compound to this, mutual compatibility increases, and it has the outstanding impact resistance and the interface property improved. This commercialization system is represented by the following scheme (1):

이다.In formula (1), R is

to be.

Syndiotactic polystyrene resin composition of the present invention is a non-halogen-type phosphate ester flame retardant to compensate for the disadvantages of halogen-based flame retardant to the sPS resin composition reinforced with impact resistance as described above, there is no generation of harmful gases to the human body It has environmentally friendly flame retardant properties.

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

(A) Syndiotactic Polystyrene (sPS)

sPS is polymerized in the catalyst system which consists of a novel metallocene catalyst and a promoter. The metallocene catalyst has a structure in which an auxiliary ligand of a transition metal compound and a functional group of the compound are linked to each other, and vary greatly depending on the kind of the transition metal compound or the kind of the compound having two or more functional groups and the molar ratio of each reactant. May exist in the form.

(B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS)

SEBS is a shock modifier added as a rubber component to increase the impact strength of syndiotactic polystyrene.

(C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA)

SEBS-MA is a compatibilizer added to increase the compatibility of syndiotactic polystyrene with rubber components and is prepared by treating styrene / butadiene / styrene with maleic anhydride.

(D) polyphenylene oxide (PPO)

PPO is added to increase the compatibility of syndiotactic polystyrene with the rubber component.

(E) syndiotactic polystyrene-maleic anhydride (sPS-MA)

sPS-MA is added to increase the compatibility of the rubber component and syndiotactic polystyrene (sPS) to increase the compatibility of the interface.

(F) diamine compounds

The diamine compound serves as a medium for inducing a coupling reaction between compatibilizers having polar groups.

(G) Phosphate Ester Flame Retardant

Non-halogen form phosphate ester flame retardants impart environmentally friendly flame retardancy.

(H) glass fiber (GF)

Glass fiber was applied as an inorganic filler. Glass fiber is added in the quantity of 5-40 weight part with respect to 100 weight part of polystyrene resin compositions.

Syndiotactic polystyrene resin composition of the present invention may be added dropping inhibitors, impact modifiers, processing aids, thermal stabilizers, antioxidants, light stabilizers and the like, pigments, dyes and sulfates, asbestos, talc, silica, ceramics Inorganic fillers such as these may also be added.

Syndiotactic polystyrene composition of the present invention can be more clearly understood by the following examples, the following examples are merely illustrative purposes of the present invention and are not intended to limit the scope of the invention.

Example

(A) syndiotactic polystyrene (sPS), (B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS), (C) hydrogenated styrene / butadiene / used in the resin compositions of the following Examples and Comparative Examples Styrene-maleic anhydride (SEBS-MA), (D) polyphenylene oxide (PPO), (E) syndiotactic polystyrene-maleic anhydride (sPS-MA), (F) diamine compound, (G) phosphate ester flame retardant Preparation and specifications of the and other additives are as follows.

(A) Syndiotactic Polystyrene (sPS)

In order to control the morphology of the polymer produced, polymerization was carried out in a glass scale reactor to obtain polystyrene having a syndiotacticity of 97% or more.

(B) hydrogenated styrene / butadiene / styrene block copolymer (SEBS)

SEBS was used as Kraton G-1651, a commercial product from Shell.

(C) hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA)

As SEBS-MA, M-1913, a commercial product of Asahi Japan, was used.

(D) polyphenylene oxide (PPO)

As the PPO, P401, a commercial product of Asahi Corp., was used.

(E) syndiotactic polystyrene-maleic anhydride (sPS-MA)

sPS-MA used a product obtained by stirring dicumyl peroxide (DCP) and maleic anhydride from a self-polymerized syndiotactic polystyrene in a batch reactor. At this time, the maleic anhydride contained was 1.05%.

(F) diamine compounds

The diamine compound represented by the following structural formula was used.

(G) Phosphate Ester Flame Retardant

As a phosphate ester flame retardant, PX-200, a commercial product of Daihachi Chemical Co., Ltd., was used. The chemical name is Resorcinolbis (di2,6 xylenyl phosphate).

Each of the components was prepared in the resin compositions of Examples 1 and 2 and Comparative Examples in the composition shown in Table 1.

Flame retardancy was evaluated by UL94 standard test method for 1/8 ", 1/10", 1/12 ", 1/16" thickness.

In Example 1, it was burned at all thicknesses, and in Example 2, it was burned at all thicknesses, but it was confirmed that it had self-plasticity. In Example 3, flame retardancy of V-2 at 1/10 "and V-1 at 1/8" was shown. Characteristically, the combustion time was long or dripping occurred during combustion. Example 4 showed the flame retardancy of V-1 at all thicknesses. Hydrogenated styrene / butadiene / styrene block copolymer (SEBS), hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA), syndiotactic polystyrene-maleic anhydride (sPS) from the flame retardant test results for Examples 1-4 It was found that the smaller the content of -MA) and the diamine compound, the better the flame retardancy. As in Comparative Example 2, the flame retardancy of V-0 was shown for the sPS resin composition containing no SEBS, SEBS-MA, sPS-MA and diamine compound. In other words, in order to maximize the flame retardancy only it can be seen that the mixture structure consisting of sPS and PPO only.

The compositions of Example 4 and Comparative Example 1 were extruded at a processing temperature of 280 ° C. in a conventional twin screw extruder in order to evaluate the mechanical properties and the applicability of the blending process to prepare pellets. The prepared pellets were dried for 3 hours at a temperature of 80 ° C., and then injected in a 6 Oz injection molding machine under conditions of a molding temperature of 300 ° C. to prepare physical specimens. The mechanical properties were measured and the results are shown in Table 2.

ingredient Example 4 Comparative Example 1 Yield strength (kgf / cm ² ) ⁽¹⁾ 608 439 Breaking Strength (kgf / cm ² ) ⁽¹⁾ 460 427 Elongation (%) ⁽²⁾ 10 4 Flexural Rigidity (kgf / cm ² ) ⁽²⁾ 1,017 711 Flexural Strength (kgf / cm ² ) ⁽²⁾ 28,020 24,410 Izod impact strength (kgfcm / cm) ⁽²⁾ 37.1 40.0

⁽¹⁾ Measured according to ASTM D638, ⁽²⁾ ASTM D790.

As shown in the results of Table 2, the mechanical strength increased and the impact strength decreased somewhat as the flame retardant properties were improved. This is because the crystallinity of syndiotactic polystyrene (sPS) is inhibited by the mixed polyphenylene oxide (PPO). However, it can be seen that the reaction compatibilization system by the coupling reaction of the diamine compound is excellent in compatibility enough to compensate for the decrease in the impact strength, so that no significant difference appears. Therefore, it is possible to prepare a resin composition with improved mechanical strength according to the flame retardant properties of the desired resin, and when only flame retardant properties are required, a simple blended resin composed of sPS, PPO, and phosphate ester flame retardant without using a reaction commercialization system The composition can be applied. In other words, it was possible to obtain a non-halogen flame-retardant syndiotactic polystyrene resin composition provided in a variety of applications.

The present invention is syndiotactic polystyrene (sPS) hydrogenated styrene / butadiene / styrene as a rubber component, styrene / butadiene / styrene maleic anhydride (SEBS-MA) and syndiotactic polystyrene maleic anhydride (sPS-MA), diamine compounds By applying phosphate ester flame retardant and polyphenylene oxide (PPO) in the optimal content to the syndiotactic polystyrene resin composition with improved impact strength by providing a compatibilizing agent to provide an environmentally friendly and flame retardant syndiotactic polystyrene resin composition Has an effect.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.                     

Claims (3)

(A) 46-94 parts by weight of syndiotactic polystyrene (sPS); (B) 1 to 20 parts by weight of hydrogenated styrene / butadiene / styrene block copolymer (SEBS); (C) 1 to 10 parts by weight of hydrogenated styrene / butadiene / styrene-maleic anhydride (SEBS-MA); (D) 20 to 48 parts by weight of polyphenylene oxide (PPO); (E) 1 to 10 parts by weight of syndiotactic polystyrene-maleic anhydride (sPS-MA); (F) 0.5 to 10 parts by weight of the diamine compound; And (G) 5 to 30 parts by weight of a phosphate ester flame retardant; Impact resistant syndiotactic polystyrene resin composition excellent in flame retardancy and mechanical properties, characterized in that consisting of. The syndiotactic polystyrene resin composition having excellent flame retardancy and mechanical properties according to claim 1, wherein the glass fiber (GF) is further added in an amount of 5 to 40 parts by weight. The method of claim 1, further comprising an inorganic filler such as flame retardant, anti-dropping agent, impact modifier, processing aid, heat stabilizer, antioxidant, light stabilizer, pigment, dye and sulfate, asbestos, talc, silica and / or ceramic. Syndiotactic polystyrene resin composition having excellent flame retardancy and mechanical properties.