KR100694467B1 - Styrene-based Resin Composition With Excellent Impact Resistance - Google Patents

Abstract

The present invention relates to a high impact styrene resin composition excellent in impact resistance, in particular low temperature impact resistance, the styrene resin composition of the present invention is an average of the flame retardant, flame retardant aid and rubber polymer in the base resin made of rubber reinforced styrene copolymer And a styrene-containing graft copolymer having a controlled particle size.

Rubber reinforced styrene resin, impact resistance, low temperature impact resistance, styrene-containing graft copolymer, flame retardant

Description

Styrene-based resin composition with excellent impact resistance {Styrene-based Resin Composition With Excellent Impact Resistance}

The present invention relates to a styrene resin composition having excellent impact resistance, in particular low temperature impact resistance, and more particularly, to a styrene-based resin composed of a rubber-reinforced styrene-based copolymer, an average particle diameter of a flame retardant, a flame retardant aid, and a rubber polymer is controlled. The present invention relates to a flame-retardant styrene-based resin composition comprising a graft copolymer, which is easy to be applied to various fields without appearance defects under various molding conditions while maintaining rigidity and flowability.

In general, styrene resins reinforced with rubber polymers have good physical properties such as moldability, rigidity, heat resistance, and fluidity, and thus are used in various industrial fields including office equipment, home appliances, electric and electronic parts, automotive parts, and sundries. However, rubber-reinforced styrenic resins have a fire property in spite of their excellent processability and physical properties, which has raised the issue of stability. Accordingly, various halogen-based flame retardants, phosphorus-based flame retardants, and inorganic flame retardants have been raised to secure flame retardancy. The flame retardancy was imparted through the addition method, and the halogen-based flame retardant having excellent flame retardant effect has been widely applied to date.

In addition, the flame retardant styrene resin has recently been thinning the housing (housing) according to the consumer's preference for large products, and is exposed to the harsh product environment according to various applications. However, the impact resistance possessed by conventional flame retardant styrene resins does not reach the level required by a thin film product or an exposed environment under severe conditions. In particular, there is a further demand for improving the impact resistance at low temperatures, which has a direct effect when the environment to which the final product is applied is a low temperature harsh condition.

A general method of improving the impact resistance of flame retardant styrene resins is to add an impact modifier, and in particular, to improve the low temperature impact resistance, Korean Patent Publication No. 2002-0024638 adds a block copolymer of styrene-butadiene. Korean Patent Publication No. 194-0001068 proposes a method of improving the low temperature impact resistance by adding an appropriate amount of chlorine-based flame retardant and silicone oil, but the above methods do not present a comparison result with other impact modifiers, so the superiority can be confirmed. none.

In addition, Japanese Laid-Open Patent Publication No. 1999-343373 discloses a method of improving impact resistance by controlling the particle size distribution of rubber particles of the impact-resistant polystyrene resin itself, and Japanese Laid-Open Patent Publication No. 194-256618 discloses a flame retardant resin. Disclosed is a method for adding polyphenylene ether as a method for improving the Izod impact strength. While the above methods achieve some degree of improvement in impact resistance at room temperature of the flame retardant styrene resin, the importance of low temperature impact resistance is overlooked. In particular, when the product is enlarged and the application conditions are severe, the application of the impact modifier increases the frequency of product breakdown even with a small external shock, and thus there is a need for a method of improving the product.

In order to solve the above problems, an object of the present invention is to provide a flame retardant styrene resin composition excellent in impact resistance, in particular low temperature impact resistance.

The above object of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention is a flame-retardant styrene resin composition,

A) 100 parts by weight of the rubber-reinforced styrenic copolymer base resin

B) Flame retardant, characterized in that it comprises 0.1 to 15 parts by weight of a styrene-containing graft copolymer grafted styrene, or styrene and a styrene compound copolymerizable therewith in a conjugated diene rubber having an average particle diameter of 500 to 4000 kPa. Provided is a styrene resin composition.

Hereinafter, the present invention will be described in detail.

Styrene-based resin composition having a flame-retardant performance according to the present invention with respect to 100 parts by weight of the base resin consisting of a rubber-reinforced styrene-based copolymer; 1 to 30 parts by weight of one or more flame retardants selected from the group consisting of halogen compounds, phosphorus compounds and epoxy compounds; 0.5 to 15 parts by weight of one or more flame retardant aids selected from the group consisting of antimony oxide, zinc compound, barium borate, zirconium oxide, talc and mica and 0.1 to 15 parts by weight of styrene-containing graft copolymer.

Hereinafter, the properties, functions, and composition ratios of the components of the present invention will be described in detail.

(1) Rubber Reinforced Styrene Copolymer

The rubber-reinforced styrene-based copolymer is formed by dispersing a rubber polymer in the form of particles on a matrix made of a styrene-based polymer. As the polymerization method, bulk polymerization, suspension polymerization, emulsion polymerization may be used in all, and preferably, bulk polymerization is used. At the time of bulk polymerization, the rubber polymer is dissolved in a styrene monomer and then stirred, and the polymerization is carried out by adding a polymerization initiator thereto.

The styrene-based monomer used in the rubber-reinforced styrene-based copolymer is mainly used a styrene-based compound, may be used by copolymerizing a compound capable of copolymerizing with the styrene-based compound.

The rubber polymer used in the rubber-reinforced styrenic copolymer of the present invention is preferably included in the total weight of the rubber-reinforced styrenic copolymer 3 to 30% by weight, more preferably 4 to 15% by weight. When the content is less than 3% by weight, the impact resistance is insufficient, and when the content exceeds 30% by weight, there is a problem in that thermal stability is lowered, melt fluidity is lowered, and gel is generated. In addition, the rubber polymer preferably has a particle size of 0.5 ~ 6㎛, it is preferable that the glass transition temperature is -10 ℃ or less. If the glass transition temperature exceeds -10 ℃, the impact resistance is lowered.

The styrene-based compound is, in addition to styrene, nuclear alkyl-substituted styrene such as p-methyl styrene, 2,4-dimethyl styrene, or ethyl styrene; Or alpha -alkyl substituted styrene such as alpha -methyl styrene or alpha -methyl-p-methyl styrene. The styrene compounds may be used alone or in combination of two or more thereof.

As the compound copolymerizable with the styrene-based compound, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile, maleic anhydride, and the like may be used.

In addition, the rubber polymer used in the rubber-reinforced styrene-based copolymer is a rubber polymer containing polybutadiene, acrylate or methacrylate, styrene-butadiene-styrene copolymer, styrene-butadiene copolymer, polyisoprene, butadiene-isoprene air Coalescing or natural rubber can be used. Preferably, polybutadiene or styrene-butadiene copolymer is used, and more preferably polybutadiene is used. As the polybutadiene, a low cis polybutadiene, a hycis polybutadiene or a mixture thereof may be used.

The styrene-based compound may be grafted to a conjugated diene rubber by a conventional polymerization method to prepare a rubber-reinforced styrene copolymer, but bulk polymerization is preferable as the polymerization method. Also in the method of adding a monomer at the time of polymer manufacture, the batch addition method or the method of mixing a batch addition method and a continuous addition method can be used.

More preferred as a rubber-reinforced styrene-based copolymer is a high impact butadiene-styrene (HIPS) resin obtained by grafting styrene to butadiene rubber.

(2) flame retardant

The present invention adds a flame retardant in a certain ratio in order to impart flame retardancy to the resin, the flame retardant may be selected from the group consisting of halogen compounds, phosphorus compounds and epoxy compounds.

Examples of the halogen compound include tetra bromo bisphenol A (TBBA), TBBA phenoxy resin, TBBA carbonate oligomer, brominated epoxy oligomer (BEO), octabromodiphenyloxide, Decabromodiphenyloxide, tribromophenoxyethane, hexabromodiphenoxyethane, decabromodiphenylethane, ethylenebis (tetrabromophthalimide) ethylenebis (tetrabromophthalimide), and 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine (2,4,6-tris (2,4,6- tribromophenoxy) 1,3,5-triazine).

The phosphorus compounds include triphenylphosphate, tri (hydroxyphenyl) phosphate, and tricresylphosphate.

The epoxy compound is preferably a brominated epoxy oligomer in which an epoxy terminal is substituted with tribromophenol. More preferably, it is an epoxy oligomer of the following general formula (1) which has a molecular weight of 500-4000.                     

Where

R is

이고,

ego,

R 'is

이며,

Is,

X is Br or Cl, a, b, c and d are integers from 1 to 4, n is an integer of 1 or more.

In the present invention, the flame retardant is preferably 1 to 30 parts by weight, when less than 1 part by weight, no flame retardant effect is observed, and when it exceeds 30 parts by weight, the mechanical properties and thermal stability of the resin are lowered, which is not preferable.

(3) flame retardant supplements

The present invention adopts a flame retardant adjuvant, the flame retardant adjuvant may be used by selecting one or more from the group consisting of antimony oxide, zinc compound, barium borate, zirconium oxide, talc and mica.

The antimony oxide includes antimony trioxide, antimony tetraoxide, antimony pentoxide, and the like.

The zinc compound includes zinc borate, molybdenum zinc, zinc sulfide and the like.

Among the flame retardant aids described above, antimony trioxide is particularly preferred for HIPS resins.

In the present invention, the flame retardant adjuvant is preferably 0.5 to 15 parts by weight, when less than 0.5 parts by weight, the flame retardant effect is not seen, when it is more than 15 parts by weight, the mechanical properties and processability of the resin is lowered is not preferred.

(4) styrene-containing graft copolymer

The present invention applies a styrene-containing graft impact modifier without impaired appearance even under a variety of molding conditions while imparting high impact characteristics, the styrene-containing graft copolymer is conjugated to the average particle diameter adjusted to 500 ~ 4000Å through polymer polymerization A copolymer obtained by grafting styrene or styrene and a styrene compound copolymerizable with the diene rubber. The conjugated diene-based rubber polymerization and styrene graft reaction can be either a bulk, suspension, or emulsion polymerization method, but preferably an emulsion polymerization method is used.

The styrene-containing graft copolymer used in the present invention serves to realize the low temperature impact resistance characteristics of the rubber-reinforced styrene resins, and is used by increasing the content of the rubber polymer with an average particle diameter adjusted and being capable of styrene or styrene and copolymerization therewith. The styrenic compound is grafted to improve the impact resistance properties of the rubber reinforced styrenic copolymer. In particular, since the content of the rubber polymer in the styrene-containing graft copolymer is very high and fine by adjusting the average particle diameter of the rubber to 500 to 4000Å, it is possible to realize the maximum impact resistance effect with a small content and to minimize the influence on the flowability of the base resin. Crazy In addition, there is also an advantage that the stiffness of the base resin is not reduced due to the fine rubber particles, the rubber particle shape is spherical and the particle size distribution is controlled to ensure the beautiful appearance of the molding under various molding conditions.

A typical method for preparing a rubber polymer in the styrene-containing graft copolymer is emulsion polymerization, in which a total of 100 parts by weight of the conjugated diene compound monomers, 0.5 to 2.5 parts by weight of an emulsifier, 0.2 to 1.5 parts by weight of a polymerization initiator, 0.2 to 1.0 parts by weight of an electrolyte, 0 to 0.5 parts by weight of the molecular weight modifier, 75 to 100 parts by weight of ion-exchanged water are reacted and the polymerization inhibitor is added to complete the reaction.

The conjugated diene compound is 1,3-butadiene, isoprene, chloroprene, pyrrylene, and the like, and comonomers thereof are also possible, and preferably 1,3-butadiene.

Styrene is grafted to 50 to 90% by weight of the rubber polymer produced by the polymerization method to complete the styrene-containing graft copolymer, which is also commonly used for emulsion polymerization. Styrene can be administered once or several times by dividing 10 to 50% by weight, respectively, in batch or continuous administration.In this case, 0.5 to 3.0 parts by weight of emulsifier, 0.05 to 1.0 parts by weight of initiator, etc. in order to induce stability of emulsion polymerization and initiation reaction. This is used.                     

The grafted styrene is, in addition to styrene, nucleoalkyl substituted styrene such as p-methyl styrene, 2,4-dimethyl styrene, or ethyl styrene; Or alpha -alkyl substituted styrene such as alpha -methyl styrene or alpha -methyl-p-methyl styrene. The said styrene compound can be used individually or in mixture of 2 or more types.

In the present invention, the rubber average particle diameter and content of the rubber polymer in the styrene-containing graft copolymer are preferably 500 to 4000Å and 50 to 90% by weight, respectively, and have a styrene having a rubber mean particle size of less than 500Å and a rubber content of less than 50% by weight. The graft copolymer has a slight impact reinforcing effect, with 4000 kPa and more than 90% by weight weakening the rigidity of the resin. More preferably, it is 2000 mm diameter and 70 weight% of rubber content. When the content of the styrene-containing graft copolymer is 100 parts by weight of the total rubber-reinforced styrenic copolymer, 0.1 to 15 parts by weight is preferable, and when it is less than 0.1 parts by weight, it is difficult to exert an effect, and when it is more than 15 parts by weight. Stiffness and flowability are reduced.

(5) additive

In addition to the above components, the styrene resin composition having flame retardant performance of the present invention may further include one or more additives selected from the group consisting of lubricants, thermal stabilizers, antioxidants, light stabilizers, anti-dropping agents, pigments, and inorganic fillers, depending on the use. Can be done.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples.

EXAMPLE                     

Example 1

Preparation of Rubber Reinforced Styrene Copolymer (HIPS)

A solution containing 7.0 parts by weight of a hysis polybutadiene having a rubber average particle diameter of 5 µm, 73.9 parts by weight of styrene monomer, 19.07 parts by weight of ethyl benzene and 0.03 parts by weight of t-butylperoxy isopropyl carbonate as an initiator was continuously polymerized by transferring. . The first stage reactor is stirred at 85 rpm and the temperature is 126 ° C., the second stage reactor is at 20 rpm and the temperature is 138 ° C., the third stage reactor is at 15 rpm and the temperature is 150 ° C., and the fourth stage reactor is 8 rpm. The polymerization was carried out at a temperature of 155 ° C. After the polymerization as described above, the unreacted monomer and the solvent were removed by passing the polymerization solution from the final reactor through a two-stage devolatilization apparatus. At this time, 0.1 parts by weight of liquid paraffin having a viscosity of 100 cst was added to the inlet of the devolatilization device in two stages, and was discharged from the devolatilizer and pelletized through an extruder to obtain a rubber-reinforced styrene copolymer (HIPS1).

Preparation of Styrene-containing Graft Copolymer (SB)

The rubber polymer of the styrene-containing graft copolymer (SB) is a total of 75 parts by weight of 1,3-butadiene as a monomer, 1.0 part by weight of sodium dodecyl benzene sulfonate as an emulsifier, 1.5 parts by weight of potassium oleate salt, 0.2 parts by weight of initiator potassium persulfate. Parts, 1.0 parts by weight of potassium carbonate, 0.2 parts by weight of tertiary dodecylmeraptan, molecular weight modifier, 100 parts by weight of ion-exchanged water, reacted at a temperature of 65 ° C to 75 ° C for 4 to 15 hours, and then the remaining conjugated diene. Compound monomers and molecular weight modifiers were administered in a batch or continuous (sequential) administration for 10 to 20 hours at 70 to 85 ° C. The rubber average particle diameter of the rubber polymer is adjusted to 2000 mm by adjusting the emulsifier, initiator, electrolyte content and polymerization time. When the polymerization conversion rate is 80 to 95%, a polymerization inhibitor is added to stop the polymerization.

Styrene is grafted to 70% by weight of the rubber polymer prepared to complete the styrene-containing graft copolymer, and 30% by weight of styrene is divided into one or several times, respectively. And 0.3 parts by weight of potassium oleate salt as an emulsifier, 0.1 parts by weight of tertiary butyl hydroperoxide as an initiator in order to induce the initial reaction. The finished styrene-containing graft copolymer was prepared by adding 1 part by weight of sulfuric acid as a flocculant and 1.5 parts by weight of IR-245 as an antioxidant to obtain a coagulum, and dried to obtain a powder.

100 parts by weight of rubber-reinforced styrene copolymer (HIPS) prepared as described above, 1 part by weight of styrene-containing graft copolymer (SB), 23 parts by weight of brominated epoxy oligomer (BEO) as a flame retardant, antimony trioxide (Sb) as a flame retardant aid ₂ O ₃ ) 4 parts by weight of 1 part by weight of antioxidant, 1 part by weight of light stabilizer and 1 part by weight of lubricant were mixed uniformly with a mixer, and then a styrene resin composition in pellet form was prepared using a twin screw extruder.

The prepared pellets were injection molded to prepare specimens for physical property evaluation, and their physical properties were evaluated in the following manner.

Izod impact strength: evaluated for 1/8 inch notched specimens by ASTM D256 test method.

* Izod low temperature impact strength: Izod impact strength was evaluated at a temperature of -10 ℃.

* Fluidity (MFR): It was evaluated under conditions of 200 ° C and 5 kg load by the ASTM D1238 test method.

Tensile Strength (TS): evaluated at a rate of 5 cm / min by the ASTM D638 test method.

Flexural Strength (FS): evaluated at a rate of 1.5 cm / min by the ASTM D790 test method.

* Flame retardancy: evaluated at 1/16 inch thickness according to the vertical test method according to UL-94.

The composition of the components used in Example 1 is shown in Table 1.

Example 2

Except that 3 parts by weight of the styrene-containing graft copolymer was added in Example 1, after preparing the resin in the same manner as in Example 1, the physical properties thereof were evaluated and the results are shown in Table 2.

Example 3

Except that 5 parts by weight of the styrene-containing graft copolymer was added in Example 1, after preparing the resin in the same manner as in Example 1, the physical properties thereof were evaluated and the results are shown in Table 2.

Comparative Example 1

Except for applying the styrene-containing graft copolymer in Example 1, except that the composition as shown in Table 1 to prepare a resin in the same manner as in Example 1 to evaluate their physical properties and the results Table 2 shows.

Comparative Example 2

Instead of the styrene-containing graft copolymer in Example 1, 3 parts by weight of Tufprene 125 (Tufprene 125, Asahi) was added as a block copolymer (SBS) made of styrene-based and olefin-based elastomers, and as shown in Table 1 Except for the composition, the resins were prepared in the same manner as in Example 1, their physical properties were evaluated, and the results are shown in Table 2.

Comparative Example 3

Instead of the styrene-containing graft copolymer in Example 1, 5 parts by weight of Tuprene 125 (Tufprene 125, Asahi) was added as a block copolymer (SBS) consisting of styrene-based and olefin-based elastomers, as shown in Table 1 Except for the composition, the resins were prepared in the same manner as in Example 1, their physical properties were evaluated, and the results are shown in Table 2.

division Example Comparative example One 2 3 One 2 3 Composition Basic resin HIPS 100 100 100 100 100 100 Flame retardant BEO 23 23 23 23 23 23 Flame Retardant Supplements Sb ₂ O ₃ 4 4 4 4 4 4 Styrene-containing graft copolymer SB One 3 5 - - - Styrene-based olefin block copolymer SBS - - - - 3 5 Etc 3 3 3 3 3 3

Properties Example Comparative example One 2 3 One 2 3 Izod (1/8 ", 23 ° C) 9.0 9.7 10.7 5.2 8.9 9.7 Izod (1/8 ", -10 ° C) 7.0 7.2 7.4 3.1 6.1 6.9 MFR 12.3 12.1 11.9 12.4 10.3 10.3 TS 299 291 279 310 295 294 FS 501 490 435 511 499 487 Flame retardancy V-0 V-0 V-0 V-0 V-0 V-0

As shown in Table 2, Examples 1 to 3 including the styrene-containing graft copolymer can be seen to be excellent in high impact properties, particularly low temperature impact resistance as the content of the styrene-containing graft copolymer increases. Comparative Example 1 shows a sharp decrease in impact resistance because no impact modifier is applied, and Comparative Examples 2 and 3 show similar impact characteristics to styrene-containing graft copolymers at room temperature, but weak at low temperature impact resistance.

As described above, the styrene resin composition having flame retardant performance according to the present invention is a styrene-containing graft grafted with a styrene compound and a styrene compound on a rubber-reinforced styrenic copolymer with a flame retardant, a flame retardant aid, and a conjugated diene rubber having an average particle size controlled. It is a useful invention that the impact copolymer, in particular low temperature impact resistance properties, is added by adding a copolymer in a proportion.

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations are set forth in the appended claims. It is natural to belong.

Claims (12)

In the flame retardant styrene resin composition, A) A rubber polymer having a particle diameter of 0.5 to 6 µm and a glass transition temperature of -10 ° C. or less is dispersed on a mattress made of a styrene compound polymer or a copolymer obtained by copolymerizing a styrene compound and a compound copolymerizable therewith. 100 parts by weight of the rubber-reinforced styrenic copolymer base resin, B) Styrene-containing graft copolymer 0.1 to 15, in which 50 to 90% by weight of conjugated diene rubber having an average particle diameter of 500 to 4000 mm is grafted to 10 to 50% by weight of styrene or styrene and a styrene compound copolymerizable therewith. A flame retardant styrene resin composition comprising a weight part. delete The method of claim 1, A flame retardant styrene resin composition comprising at least one flame retardant selected from the group consisting of halogen compounds, phosphorus compounds and epoxy compounds, in an amount of 1 to 30 parts by weight based on 100 parts by weight of the rubber-reinforced styrenic copolymer base resin. The method of claim 3, The halogen compound is tetrabromobisphenol A (TBBA), TBBA-based phenoxy resin, TBBA-based carbonate oligomer, brominated epoxy oligomer, octabromodiphenyl oxide, decabromodiphenyl oxide, tribromophenoxy ethane, hexabromo Diphenoxyethane, decabromodiphenylethane, ethylenebis (tetrabromophthalimide) and 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine Flame retardant styrene-based resin composition, characterized in that at least one selected from the group consisting of. The method of claim 3, Flame-retardant styrene resin composition characterized in that the phosphorus compound is selected from the group consisting of triphenyl phosphate, tri (hydroxyphenyl) phosphate and tricresyl phosphate. The method of claim 3, Flame-retardant styrene-based resin composition, characterized in that the epoxy compound is a brominated epoxy oligomer substituted by the epoxy terminal with tribromophenol. The method of claim 3, Flame-retardant styrene resin composition characterized in that the epoxy compound has a molecular weight of 500 to 4000, and is an epoxy oligomer of the formula (1). [Formula 1]

Where R is

ego, R 'is

Is, X is Br or Cl, a, b, c and d are integers from 1 to 4, n is an integer of 1 or more. The method of claim 1, Antimony oxide, zinc compound, barium borate, zirconium oxide, talc and mica are used at least 0.5 to 15 parts by weight based on 100 parts by weight of the rubber-reinforced styrenic copolymer base resin selected from the group consisting of Flame retardant styrene resin composition. The method of claim 8, Flame retardant styrene-based resin composition, characterized in that the antimony oxide is selected from the group consisting of antimony trioxide, antimony tetraoxide and antimony pentoxide. The method of claim 8, Flame retardant styrene resin composition, characterized in that the zinc compound is selected from the group consisting of zinc borate, molybdenum zinc and zinc sulfide. delete The method of claim 1, The flame retardant styrene resin composition further comprises one or more additives selected from the group consisting of lubricants, heat stabilizers, antioxidants, light stabilizers, anti-drip agents, pigments and inorganic fillers.