KR20040012014A - Flame-Retardant Styrenic Resin Composition with Excellent Impact Strength and Appearance - Google Patents

Abstract

PURPOSE: A flame retardant styrene resin composition which has excellent impact resistance, thermostability, appearance characteristics, and fluidity, thereby being applicable to exterior material for articles used in TV, VCR, copy machine, or FAX is provided by using a mixture of polystyrene with different rubber particle sizes, flame retardants which is selected from melt or non-melt halogen compound or mixture thereof, antimony trioxide, impact modifier, and lubricant of olefin compounds. CONSTITUTION: The flame retardant composition comprises: (A) 100 pts.wt. of polystyrene reinforced with rubber comprised of (a1) 50-90 wt% of polystyrene resin reinforced with rubber having 0.2-0.8 micrometer of average rubber particle size, and (a2) 50-10 wt% of polystyrene resin reinforced with rubber having 2.0-3.0 micrometer of average rubber particle size; (B) 5-25 pts.wt. of halogen compound; (C) 1-10 pts.wt. of antimony trioxide; (D) 0.5-10 pts.wt. of antimony trioxide; (E) 1-10 pts.wt. of impact modifier obtained by carrying out graft polymerization of styrene monomer and acrylonitrile monomer with a rubber selected from a group consisting of butadiene rubber, isoprene rubber, butadiene-styrene copolymer or alkylacrylate rubber; and (F) 0.1-5 pts.wt. of olefin-based lubricant.

Description

Flame-Retardant Styrenic Resin Composition with Excellent Impact Strength and Appearance

Field of invention

The present invention relates to a styrene resin composition having excellent impact strength and fluidity, thermal stability and flame retardancy. More specifically, the present invention uses the particle size of the rubber used in the rubber-reinforced high-impact polystyrene resin while using the non-melting halogen compound or the molten halogen compound as the main flame retardant and the antimony trioxide as the flame retardant aid in the rubber-reinforced polystyrene resin copolymer. By using the modulated and grafted impact modifier, the present invention relates to a flame retardant styrene resin composition having improved impact strength, fluidity, thermal stability, and improved appearance characteristics.

Background of the Invention

In general, styrene-based resins have good processability and mechanical strength, and are mainly used as exterior materials for electrical and electronic products. However, the resin itself does not have a resistance to flame, and when the spark is ignited by an external ignition source, the resin itself acts as an energy to assist combustion and continuously spreads the fire. Let's go.

In view of this, countries such as the United States and Europe have legalized to use only flame-retardant resins for the manufacture of molded parts of electronic products in order to ensure stability of fires of electronic products.

Examples of the method of imparting flame retardancy to a resin having such characteristics include an additional flame retardant method of adding a flame retardant and a flame retardant aid, and a polymerization flame retardant method of preparing a resin using a special monomer containing a flame retardant atom during polymerization. Can be. Among them, polymerized flame retardation has been studied in a pilot scale stage, but commercialized products have not been released due to high cost and difficulty in achieving flame retardancy. Therefore, most commercialized flame retardant resins are prepared by an additive flame retardant method in which a flame retardant containing halogen or phosphorus, which is an inert element, is added during compounding.

An additional flame retardant method in which a flame retardant is added to impart flame retardancy to a styrene resin is prepared by adding one or more components selected from halogen-containing organic compounds and antimony-containing inorganic compounds to the resin. Halogen-containing organic compounds, mainly bromine or chlorine compounds, are highly flame retardant when added to styrene-based resins, but seriously deteriorate overall physical properties such as impact strength, weather stability, heat resistance and processability of the resin itself. Therefore, in the production of flame retardant resins, it is very important to maintain excellent flame retardancy while minimizing side effects such as deterioration in physical properties and processability, appearance defects, and the like.

In the case of rubber-reinforced high-impact polystyrene resins used to prepare conventional flame-retardant resins, polymerization is performed by adding rubber during the polymerization of polystyrene resins to compensate for impact. The rubber used at this time is used to protect the internal circuits when used as an exterior material by reinforcing the impact strength. Due to the trend that the thickness of the exterior material of household appliances becomes thin and the shape becomes complicated, the general form of the rubber is a wavy resin flow. Due to the flow mark, appearance defects that are not suitable for use as exterior materials occur.

The present inventors use a halogen-containing non-melting flame retardant in the rubber-reinforced polystyrene resin copolymer as the main flame retardant, antimony trioxide as a flame retardant adjuvant, to control the particle size of the rubber used in rubber-reinforced high-impact polystyrene resin in order to solve the above problems As a result, it has led to the development of a flame retardant styrene resin composition which is excellent in flame retardancy and further improved in impact strength, flowability, thermal stability and appearance characteristics.

An object of the present invention is to provide a flame-retardant styrene resin composition excellent in impact resistance by using a mixture of rubber-reinforced polystyrene having different rubber particle size.

Another object of the present invention is to provide a styrene resin composition having excellent flame retardancy by using a non-melting halogen compound, a molten halogen compound or a mixture thereof as a flame retardant, and using antimony trioxide as a flame retardant aid.

Another object of the present invention by using a grafted impact modifier excellent in thermal stability, by minimizing the amount of the impact modifier to reduce the thermal stability when used in excess, the thermal stability and appearance properties that can be molded without appearance defects under various molding conditions It is to provide an excellent flame retardant styrene resin composition.

Still another object of the present invention is to provide a flame retardant styrene resin composition having excellent fluidity by using an olefin compound as a lubricant.

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

Flame retardant styrene resin composition of the present invention

(A) (a ₁₎ an average rubber particle size of 0.2~0.8 ㎛ reinforced rubber polystyrene resin 50 to 90% by weight, and (a ₂₎ an average rubber particle size of 2.0~3.0 ㎛ the rubber-reinforced polystyrene resin, 50-10% by weight 100 parts by weight of rubber-reinforced polystyrene resin;

(B) 5 to 25 parts by weight of a halogen compound;

(C) 1 to 10 parts by weight of antimony trioxide;

(D) 0.5 to 10 parts by weight of a styrene-butadiene impact modifier;

(E) Grafted impact modifiers 1 to 10 obtained by graft polymerization of styrene monomer and acrylonitrile monomer to rubber selected from the group consisting of butadiene rubber, isoprene rubber, copolymers of butadiene and styrene or alkyl acrylate rubber Parts by weight; And

(F) 0.1 to 5 parts by weight of olefin lubricant;

Is made of.

Hereinafter, (A) rubber-reinforced polystyrene resin, (B) halogen compound, (C) antimony trioxide, (D) impact modifier, (E) grafted impact modifier, which is each component of the flame-retardant thermoplastic resin composition of this invention, (F) ) Each of the olefin lubricants will be described in detail.

(A) Rubber reinforced polystyrene resin

The rubber-reinforced polystyrene resin (A) used in the present invention is (a ₁ ) 50 to 90% by weight of rubber-reinforced polystyrene resin having an average rubber particle size of 0.2 to 0.8 μm and (a ₂ ) an average rubber particle size of 2.0 to 3.0 μm. It consists of 50-10 weight% of phosphorus rubber reinforced polystyrene resin.

By mixing two rubber-reinforced polystyrene resins having different rubber particle sizes in the present invention, excellent appearance is ensured by the small particle rubber, and bi-modal (Bi) of the rubber particle size is a combination of small particle size / large particle rubber. Excellent impact resistance is obtained by the modal effect.

The small particle rubber-reinforced polystyrene resin (a ₁ ) may be used alone or in an amount of 90% by weight or more, but may be excellent in appearance characteristics, but may be used in an amount of 50 to 90% by weight since impact resistance is reduced when mixed with a flame retardant. In addition, the large-diameter rubber-reinforced polystyrene resin (a ₂ ) may be used alone or in an amount of 50% by weight or more, but the impact resistance is excellent, but since the appearance characteristics are deteriorated, it is preferably used in an amount of 50 to 10% by weight.

Rubber-reinforced polystyrene resins used in the present invention are prepared by mixing rubber with aromatic monoalkenyl monomers and / or alkyl ester monomers and polymerizing them using a polymerization initiator.

The rubber used in the present invention is selected from butadiene rubbers, isoprene rubbers, copolymers of butadiene and styrene, alkyl acrylate rubbers, and the like, and is used in an amount of 3 to 30 parts by weight, more preferably 5 to 15 parts by weight. It is preferable.

In addition, the monomers used herein are selected from aromatic monoalkenyl monomers, alkyl ester monomers of acrylic acid or methacrylic acid, and at least one of the monomers is added in an amount of 70 to 97 parts by weight, more preferably 85 to 95 parts by weight. It is desirable to.

As the polymerization initiator, one or more initiators selected from benzoyl peroxide, t-butyl hydroperoxide, acetyl peroxide, and cumene hydroperoxide may be used, and may be subjected to block polymerization to prepare the rubber-reinforced polystyrene resin (A). Can be.

The rubber-reinforced polystyrene resin may be prepared using a bulk polymerization, suspension polymerization, emulsion polymerization or a mixture thereof, it is preferable to use a bulk polymerization of these polymerization methods.

(B) halogen compound

In the present invention, the flame retardant is a non-melting halogen compound (b ₁ ), which is a bromine compound including tecabromodiphenyl oxide, or a molten halogen compound (b ₂ ) which is melted with a styrene resin at a processing temperature of a styrene resin. Can be used

Among the halogen compounds, the non-melting halogen-based compound (b ₁ ) is represented by the following formula (I) or (II):

Of the halogen compounds, the molten halogen-based compound (b ₂ ) is represented by the following formula (III), (IV) or (V):

Wherein n is an integer of 0 or more, and R ₁ is X is an integer from 1 to 5.

When used alone, the flame retardant is preferably 5 to 25 parts by weight, more preferably 10 to 20 parts by weight based on 100 parts by weight of the rubber-reinforced polystyrene resin (A). When 5 parts by weight or less is added, the flame retardant effect is insufficient, and when 25 parts by weight or more is used, deterioration of workability and mechanical strength occurs, thereby deteriorating the balance of physical properties.

In the case where two or more kinds of flame retardants (b ₁ , b ₂ ) are mixed and used, the main flame retardant is preferably used in an amount of 7 to 18 parts by weight based on 100 parts by weight of the rubber-reinforced polystyrene resin (A), and the non-retardant agent is a rubber-reinforced polystyrene. 1 to 7 parts by weight when the main flame retardant uses 10 to 18 parts by weight as the molten flame retardant, and 4 to 10 parts by weight when the main flame retardant uses 7 to 15 parts by weight as the non-melting flame retardant. It is preferable.

When two or more kinds of flame retardants are used in combination, if the total content of the flame retardant is 13 parts by weight or less, there is a deterioration in flame retardancy and fluidity, and in the case of 25 parts by weight or more, workability and mechanical strength are deteriorated, thereby impairing the balance of physical properties. Not good.

(C) antimony trioxide

Antimony trioxide (C) in the present invention is added as a flame retardant adjuvant to impart proper flame retardancy to the resin composition.

Antimony trioxide (C) is preferably used in an amount of 1 to 10 parts by weight, more preferably 2 to 7 parts by weight, based on 100 parts by weight of the rubber-reinforced polystyrene resin (A) of the present invention. If antimony trioxide is used in an amount less than 1 part by weight, sufficient flame retardant effect cannot be obtained, and when used in excess of 10 parts by weight, the balance of physical properties of the resin composition is not good.

(D) impact modifier

In the resin composition of the present invention, a styrene-butadiene-based or styrene-isoprene-based copolymer is used as an impact modifier for reinforcing the impact strength.

The impact modifier is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the rubber-reinforced polystyrene resin (A).

(E) Grafted impact modifier

Copolymer obtained by graft polymerization of a styrene monomer and an acrylonitrile monomer with a rubber selected from butadiene type rubbers, isoprene type rubbers, copolymers of butadiene and styrene or alkyl acrylate rubbers to reinforce the impact strength to the resin composition of the present invention. Use water as an impact modifier.

The grafted impact modifier consists of 30 to 60% by weight of styrene monomer, 0 to 10% by weight of acrylonitrile monomer and 40 to 60% by weight of rubbers, and 1 to 100 parts by weight of rubber-reinforced polystyrene resin (A). It is preferred to add 15 parts by weight.

(F) olefin lubricants

An olefin compound is used as a lubricant for reinforcing fluidity in the resin composition of the present invention. It is preferable to use the olefin type lubricant (F) whose molecular weight is 1,000-5,000.

It is preferable that the said lubricant adds 0.1-5 weight part with respect to 100 weight part of rubber reinforced polystyrene resins (A).

The styrenic flame retardant resin composition of the present invention uses rubber-reinforced polystyrene resins with controlled rubber particle size to minimize impact resistance deterioration due to the addition of flame retardants and to maintain appearance characteristics, and to use non-melting halogen compounds or molten halogen compounds as flame retardants. Use alone or as a main flame retardant by mixing a non-melting halogen compound with a nonflammable flame retardant, or by mixing a molten halogen compound with a main flame retardant as a non-flammable flame retardant and a flame retardant aid. It has sufficient flame retardancy by using antimony trioxide, and it has excellent impact strength and fluidity by minimizing the content of impact stabilizer that lacks thermal stability added to improve impact strength and lack of thermal stability that is added for improving fluidity. At the same time, thermal stability is excellent. .

In addition to the above components, an inorganic additive, a heat stabilizer, an antioxidant, other light stabilizers, pigments, and dyes may be added to the flame-retardant styrene resin composition of the present invention depending on the purpose.

The flame retardant styrene resin composition of the present invention can be produced by a known method for producing a resin composition. For example, the components of the present invention and other additives may be mixed simultaneously, then melt extruded in an extruder and made into pellets.

The present invention will be further illustrated by the following examples, which are only described for the purpose of illustrating the present invention and are not intended to limit the protection scope of the present invention.

Example

(A) rubber-reinforced polystyrene resin, (B) halogen compound, (C) antimony trioxide, (D) impact modifier, (E) grafted impact modifier, (F) olefins, used in the following examples and comparative examples The specifications of the lubricant are as follows.

(A) Rubber reinforced polystyrene resin

Rubber particle size is a 0.2~0.8 ㎛, a rubber content of 8% by weight of the rubber-reinforced polystyrene resin (a ₁₎ and the rubber particle size of 2.0~3.0 ㎛, the rubber-reinforced rubber content of 11% by weight of polystyrene resin (a ₂ ), And all of the rubber-reinforced polystyrene resin products of Cheil Industries were used.

(B) halogen compound

5 parts by weight of the non-melting halogen compound represented by the following formula (II) and 15 parts by weight of the molten halogen compound represented by the following formula (IV) were used.

(C) antimony trioxide

As a flame retardant adjuvant, Ilsung's antimony trioxide was used.

(D) impact modifier

Asahi SBR rubber was used as a styrene-butadiene impact modifier.

(E) Grafted impact modifier

A styrene-butadiene-acrylonitrile-based copolymer was used.

(F) olefin lubricants

Waxes having a molecular weight of 1,000 to 5,000 were used.

As other additives, IBANOX 1076 from CIBA-GEIGY was used as an antioxidant, and Zn-stearate from Songwon Industrial Co., Ltd. was used.

Examples 1-5

According to the content (unit is parts by weight) described in Table 1, 0.5 parts by weight of each component and antioxidant and 1 part by weight of stearic acid were added to prepare a resin composition. The resin composition was uniformly mixed with a henshell mixer, and then extruded with a twin screw extruder to prepare pellets. From the prepared pellets, a specimen for physical property test having a thickness of 1/16 "was prepared by injection molding.

Comparative Examples 1-7

As described in Table 1, it was carried out in the same manner as in the Example except for changing the content of each component.

The physical properties of the specimens molded in Examples and Comparative Examples were measured by the following method.

Impact strength was measured according to ASTM D256.

Flame retardancy was measured according to the UL-94 test method.

Appearance characteristics were evaluated by visually evaluating resin flow marks such as flow marks by using a mold having a thin thickness of a molded article, which is a form in which appearance defects are likely to appear, and a hole in which a portion of the resin joint is formed in the middle part. .

The compositions and physical properties of the resins prepared in Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 1 below.

Example Comparative Example One 2 3 4 5 One 2 3 4 5 6 7 Furtherance A a ₁ 50 60 70 80 90 100 0 10 20 30 60 80 a ₂ 50 40 30 20 10 0 100 90 80 70 40 20 B 15 15 15 15 15 15 15 15 15 15 15 15 C 5 5 5 5 5 5 5 5 5 5 5 5 D 2 2 2 2 2 4 One One One One 4 4 E 5 5 5 10 10 0 0 0 0 0 0 0 F 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Properties Izod impact strength (1/8 ", kgcm / cm) 13 12 11 14 13 5 15 14 14 13 13 11 Flame retardant V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 Exterior 4 3 3 2 One 6 10 9 8 7 8 7

* Appearance: The highest grade of 1, the lowest grade of 10, the grade of 4 or more is passed.

From the results of Table 1, the appearance and impact characteristics of the rubber-reinforced high-impact polystyrene resin in which the rubber particle size is controlled are changed according to the rubber particle size, and in particular, the small particle rubber is applied according to the Bi-Modal effect according to the rubber particle size. When using 50 to 90 parts by weight of the rubber-reinforced high impact polystyrene resin (a ₁ ), it can be seen that a product having excellent appearance characteristics and impact resistance can be obtained.

In addition, when the grafted impact modifier (E) having excellent thermal stability is added to reinforce the impact strength, the impact modifier such as lubricating agent and styrene-butadiene system, which lacks thermal stability, is reduced to a minimum, thereby providing excellent impact strength and It can be seen that it is possible to prepare a resin composition that retains appearance characteristics.

The present invention uses rubber-reinforced polystyrene mixtures having different rubber particle sizes, unmelted halogen compounds, molten halogen compounds or mixtures thereof, such as flame retardants, antimony trioxide, grafted impact modifiers having excellent thermal stability, and lubricants, which are olefinic compounds. It is excellent in impact resistance, thermal stability, appearance characteristics and fluidity, and has the effect of providing a flame-retardant styrene resin composition which can be used for molded articles of TVs, VCRs, copiers or FAX.

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) (a ₁₎ an average rubber particle size of 0.2~0.8 ㎛ reinforced rubber polystyrene resin 50 to 90% by weight, and (a ₂₎ an average rubber particle size of 2.0~3.0 ㎛ the rubber-reinforced polystyrene resin, 50-10% by weight 100 parts by weight of rubber-reinforced polystyrene resin; (B) 5 to 25 parts by weight of a halogen compound; (C) 1 to 10 parts by weight of antimony trioxide; (D) 0.5 to 10 parts by weight of a styrene-butadiene impact modifier; (E) Grafted impact modifiers 1 to 10 obtained by graft polymerization of styrene monomer and acrylonitrile monomer to rubber selected from the group consisting of butadiene rubber, isoprene rubber, copolymers of butadiene and styrene or alkyl acrylate rubber Parts by weight; And (F) 0.1 to 5 parts by weight of olefin lubricant; Flame-retardant styrene resin composition, characterized in that consisting of. The molten halogen compound (b) according to claim 1, wherein the halogen compound (B) is a non-melting halogen compound (b ₁ ) represented by the following formulas (I, II), and a molten halogen compound (b) represented by the following formulas (III, IV, V): ₂ ), or a mixture thereof, which is selected from the group consisting of flame retardant styrene resin compositions: Wherein n is an integer of 0 or more, and R ₁ is X is an integer from 1 to 5. The mixture of the non-melting halogen compound and the molten halogen compound is ₇ to 15 parts by weight of the non-melting halogen compound (b ₁ ) and the molten type with respect to 100 parts by weight of the rubber-reinforced polystyrene resin (A). Flame retardant styrene resin comprising 4 to 10 parts by weight of a halogen compound (b ₂ ) or 10 to 18 parts by weight of the molten halogen compound (b ₂ ) and ₁ to 7 parts by weight of the non-melting halogen compound (b ₁ ). Composition.