KR100454024B1 - Composition of rubber-modifide styrene resin having superior heat resistance - Google Patents

Abstract

The present invention relates to a rubber-modified styrene resin composition having excellent heat resistance, and more particularly to an aromatic non-halogen-based flame retardant to a rubber-modified styrene resin including a rubber-modified styrene-containing graft copolymer, a heat-resistant copolymer, and a styrene-containing copolymer. The present invention relates to a rubber-modified styrene resin composition having excellent processability and flame retardancy while expressing heat resistance using an aromatic phosphate containing a monophosphate and an aromatic diphosphate.

Description

Rubber modified styrene resin composition excellent in heat resistance {COMPOSITION OF RUBBER-MODIFIDE STYRENE RESIN HAVING SUPERIOR HEAT RESISTANCE}

The present invention provides a rubber-modified styrene resin having excellent heat resistance, processability, and flame retardancy by using a non-halogen-based flame retardant in a rubber-modified styrene resin including a rubber-modified styrene-containing graft copolymer, a heat-resistant copolymer, and a styrene-containing copolymer. It relates to a composition.

Rubber modified styrene resins, which are widely used in electrical and electronic products and office equipment, have excellent processability and physical properties, but studies have been continued to impart flame retardancy because they burn well.

In order to impart flame retardancy to the rubber-modified styrene resin, tetrabromobisphenol A, halogenated compounds such as epoxy bromide and chlorine compounds are used as flame retardants, and antimony compounds are used as flame retardant aids. have.

However, bromine or chlorine-containing halogen compounds used in the above method are known to decompose upon combustion to release gases harmful to the human body. Antimony compounds are also classified as toxic substances, and their use is regulated.

Therefore, the research regarding the resin composition which uses a non-halogen type compound as a flame retardant is actively progressing in recent years. However, the rubber-modified styrene resin has a problem that it is difficult to exhibit an excellent flame retardant effect when using a non-halogen flame retardant.

Accordingly, Japanese Patent Application Laid-Open No. 13-200133 discloses a rubber-modified styrene resin having a flame retardancy of UL94 V-2 grade using a non-halogen-based flame retardant to a flame-retardant rubber-modified styrene resin. It requires a large amount of flame retardant and thus has a problem of significantly lowering the heat resistance of the rubber-modified styrene resin.

In addition, in recent years, it is required to improve the heat resistance of resins due to the enlargement of the exterior material, and as a method thereof, the use of heat-resistant copolymers is gradually expanded. However, when the heat-resistant copolymer is applied to the rubber-modified styrene-based resin for the purpose of improving the heat resistance of the resin, the heat resistance is improved, but the impact resistance and the workability are deteriorated. There is a problem of adding a flame retardant.

Therefore, there is a need for a study on a rubber modified styrene resin having excellent impact resistance, workability, and flame retardancy while improving the heat resistance of the rubber modified styrene resin using a heat resistant copolymer and simultaneously reducing the amount of non-halogen flame retardant added.

In order to solve the above problems, the present invention is not only excellent in heat resistance, but also to reduce the amount of non-halogen-based flame retardant added to provide a rubber-modified styrene resin excellent in impact resistance and workability, excellent mechanical properties and flame retardancy. do.

In order to achieve the above object, the present invention is a) i) 10 to 50% by weight of a rubber-modified styrene-containing graft copolymer; ii) 20 to 70% by weight of a copolymer polymerized with alpha methyl styrene and acrylonitrile; And iii) 100 parts by weight of a rubber-modified styrenic resin comprising 20 to 70% by weight of a copolymer polymerized with styrene and acrylonitrile, b) a non-halogen flame retardant, i) aromatic monophosphate and ii) aromatic diphosphate.

It provides a rubber-modified styrene resin composition comprising 4 to 15 parts by weight of aromatic phosphate, each containing 2 to 20 parts by weight with respect to 100 parts by weight of rubber-modified styrene resin.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention while studying a method for improving the heat resistance, impact resistance, processability, and flame retardancy of the rubber-modified styrene resin, by optimizing the addition amount of the heat-resistant copolymer and styrene-containing copolymer to the rubber-modified styrene-containing graft copolymer By using this, the addition amount of the non-halogen flame retardant to the rubber-modified styrene-containing graft copolymer is not only reduced when the heat-resistant copolymer resin and the styrene-containing copolymer are applied alone, but also the heat resistance, processability, mechanical properties, and flame retardancy are further increased. It was confirmed that the improvement, and based on this, the present invention was completed.

The present invention provides a rubber-modified styrene system using a non-halogen-based compound containing an aromatic monophosphate and an aromatic diphosphate as a flame retardant in a rubber-modified styrene resin including a rubber-modified styrene-containing graft copolymer, a heat-resistant copolymer, and a styrene-containing copolymer. It relates to a resin composition.

The rubber-modified styrene-containing graft copolymer of a) iii) used in the present invention is a compound 30-65 selected from the group consisting of styrene, alphamethyl styrene, and nuclear substituted styrene in 10 to 60% by weight of rubber. weight%; And 10 to 30% by weight of a compound selected from the group consisting of acrylonitrile, methyl methacrylate, and butyl acrylate.

The rubber-modified styrene-containing graft copolymer can be prepared by a conventional polymerization method, preferably synthesized by bulk polymerization or emulsion polymerization. For example, it is preferable to use acrylonitrile / butadiene / styrene (ABS) resin in which acrylonitrile and styrene are grafted to butadiene rubber, more preferably polybutadiene, styrene-butadiene copolymer, polyisoprene, Or butadiene-isopyrene copolymer.

The rubber-modified styrene-containing graft copolymer is preferably contained in 10 to 50% by weight in the rubber-modified styrene resin.

The heat-resistant copolymer of a) ii) used in the present invention is 50 to 80% by weight of at least one compound selected from the group consisting of styrene, alphamethyl styrene, maleic anhydride, N-phenylmaleimide, nuclear substituted styrene, and It is prepared by copolymerizing 20 to 50% by weight of acrylonitrile compound.

The heat-resistant copolymer can be prepared by a conventional polymerization method, preferably synthesized by bulk polymerization or emulsion polymerization. For example, it is preferable to use alpha methyl styrene / acrylonitrile copolymer (AMS SAN) resin copolymerized with alpha methyl styrene and acrylonitrile, and more preferably, the content of alpha methyl styrene is 50 to 80% by weight. It is preferable to use an alpha methyl styrene / acrylonitrile copolymer having a weight average molecular weight of 80,000 to 170,000. In addition, the heat-resistant copolymer is preferably contained in 20 to 70% by weight in the rubber-modified styrene resin.

The styrene-containing copolymer of c) iii) used in the present invention is prepared by copolymerizing 50 to 80% by weight of the styrene compound and 20 to 50% by weight of the acrylonitrile compound.

The styrene-containing copolymer can be produced by a conventional polymerization method, preferably synthesized by bulk polymerization or emulsion polymerization. For example, a styrene / acrylonitrile copolymer (SAN) resin having a styrene content of 50 to 80 wt% and a weight average molecular weight of 50,000 to 170,000 is preferable, and more preferably a weight average molecular weight of 50,000 to 10 It is preferable to use a full styrene-acrylonitrile copolymer. In addition, the styrene-containing copolymer is preferably included in the rubber modified styrene resin 20 to 50% by weight.

In addition, the rubber-modified styrene resin of the present invention uses a non-halogen-based flame retardant to obtain a flame retardant of UL94 V-2 grade, a phosphorus compound is used as the flame retardant, preferably an aromatic phosphate compound. The aromatic phosphate compound is preferably an aromatic monophosphate, an aromatic diphosphate compound, or a mixture thereof.

The aromatic monophosphate of b) iii) used in the present invention includes trialkyl phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate and trioctyl phosphate which are not substituted with halogen; Triaryl phosphates, such as a triphenyl phosphate, a tricresyl phosphate, a trigy yl phosphate, and a cresyl diphenyl phosphate; And trialkyl-aryl phosphates such as octyl diphenyl phosphate. Preferably triaryl phosphate is used, More preferably, triphenyl phosphate, tri (4-methylphenyl) phosphate, or tri (2, 6- dimethylphenyl) phosphate is used.

The aromatic monophosphate is preferably used in an amount of 2 to 20 parts by weight based on 100 parts by weight of the rubber modified styrene resin.

As the aromatic diphosphate of b) ii) used in the present invention, it is preferable to use a compound represented by the following formula (1).

[Formula 1]

In the formula of Formula 1,

Ar _{1 to} Ar ₄ is a phenyl group or an aryl group substituted with 1 to 3 alkyl groups of C _{1 to} C ₄ ,

R is phenyl or bisphenol a,

n is an integer of 4-5.

The aromatic diphosphate is preferably used in an amount of 2 to 20 parts by weight based on 100 parts by weight of the rubber modified styrene resin.

The aromatic phosphate containing the aromatic monophosphate and aromatic diphosphate is preferably included in an amount of 4 to 15 parts by weight based on 100 parts by weight of the rubber-modified styrene resin. If the content is less than 4 parts by weight, there is a problem that the flame retardancy does not appear, and if it exceeds 15 parts by weight, the flame retardancy is excellent, but there is a problem that the heat resistance of the rubber-modified styrene resin is significantly lowered.

In addition, the rubber-modified styrenic resin composition of the present invention may further include additives such as lubricants, heat stabilizers, antioxidants, light stabilizers, anti-dropping agents, pigments, or inorganic fillers of a conventional content, if necessary, the present invention The rubber-modified styrene resin composition can be prepared by mixing in a conventional blending method.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

30 parts by weight of acrylonitrile / butadiene / styrene (ABS) resin (DP215, LG Chemical Co., Ltd.) grafted by 50% by weight of butadiene rubber to 15% by weight of acrylonitrile and 30% by weight of styrene by emulsion polymerization; 45 parts by weight of a heat-resistant copolymer (AMS SAN, 98UH, LG Chemical Co., Ltd.) polymerized by bulk polymerization of 50 to 80% by weight of alpha methyl styrene and 30 to 50% by weight of acrylonitrile; And 50 to 80% by weight of styrene and 20 to 30% by weight of acrylonitrile are polymerized by bulk polymerization to contain a rubber-modified styrene resin containing 25 parts by weight of a styrene-containing copolymer (SAN) having a weight average molecular weight of 50,000 to 100,000. Prepared.

4 parts by weight of triphenylphosphate (TPP, Daihachi Co., Ltd.), which is an aromatic monophosphate, and diphenyl phosphate (PX-200, Daihachi, Japan), which are aromatic monophosphates as 100 parts by weight of the rubber-modified styrene resin. 2 parts by weight of a rubber-modified styrene resin composition was prepared.

Example 2, and Comparative Examples 1-6

In Example 1 according to the composition and the content of Table 1 in the same manner as in Example 1 to prepare a rubber-modified styrene resin composition.

division Example Comparative example One 2 One 2 3 4 5 6 Resin (part by weight) Rubber modified styrene-containing graft copolymer 30 30 30 30 30 30 30 30 Heat resistant copolymer 45 45 70 60 - 10 70 70 Styrene-containing copolymer 25 25 - 10 70 60 - - Flame retardant (parts by weight) TPP 4 2 4 4 4 4 12 - PX-200 2 4 2 2 2 2 - 15

After mixing the rubber-modified styrene resin composition prepared in Examples 1 or 2 and Comparative Examples 1 to 6 uniformly through a Henschel mixer, a resin composition in pellet form was prepared through a twin screw extruder. Physical properties and flame retardant test specimens were prepared by injection molding from the prepared pellets, and the properties were measured by the following method, and the results are shown in Table 2 below.

A) impact strength (1/8 notch, kgf cm / cm) —measured according to ASTM D256 method.

B) flowability (g / 10 min)-ASTM using a load of 10 kgf at a temperature of 220 ° C

It was measured according to D1238.

C) Heat deflection temperature (℃)-measured according to ASTM D648 method at 18.5 kgf load

All.

D) Flame retardancy-measured according to the UL94 VB flame retardant test method, according to the following criteria

Was evaluated.

V-2: UL94 V-2 grade flame retardant NR (No Rating): no flame retardancy

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Impact Strength (IMP, ⅛ ") 15.7 12.5 7.4 8.7 23.1 19.8 3.8 2.9 Fluidity (MI) 43.2 40.4 17.6 22.3 54.7 48.2 86.8 72.4 Heat Deflection Temperature (HDT) 85.7 86.5 93.6 89.1 75.2 76.4 67.8 68.2 Flame retardancy V-2 V-2 NR NR V-2 V-2 V-2 V-2

Through Table 2, Examples 1 to 2 using an aromatic phosphate (aromatic monophosphate + aromatic diphosphate) as a non-halogen-based flame retardant to the rubber-modified styrene resin according to the present invention shows a flame retardancy of the V-2 grade I could confirm it. In particular, when the optimized amount of the heat-resistant copolymer and the styrene-containing copolymer is applied to the rubber-modified styrene-containing graft copolymer as in Examples 1 to 2, UL94 V-2 grade flame retardant is excellent while having excellent heat resistance, impact resistance and workability. It was found that a rubber-modified styrene resin having a degree can be produced.

On the other hand, as shown in Comparative Examples 1 and 2, the heat-resistant copolymer was used alone in the rubber-modified styrene-containing graft copolymer (Comparative Example 1), or the content of the styrene-containing copolymer used with the heat-resistant copolymer was 10% by weight. When used in parts or less (Comparative Example 2), it was found that the resin had excellent heat resistance but no flame retardancy. In addition, when using the styrene-containing copolymer alone in the rubber-modified styrene-containing graft copolymer as in Comparative Examples 3 to 4, or when the content of the styrene-containing copolymer used in combination with the heat-resistant copolymer is 10 parts by weight or less, UL94 The flame retardancy of V-2 grade was shown, but the heat resistance was insignificant.

In addition, when the aromatic monophosphate (TPP) and aromatic diphosphate (PX-200) alone are included as in Comparative Examples 4 to 5, respectively, flame retardancy of UL94 V-2 grade can be secured according to the increase of the added amount. As a result, it can be seen that the impact strength and the thermal deformation temperature decrease rapidly.

As described above, the rubber-modified styrene-based resin of the present invention is not only excellent in heat resistance by using an optimized amount of the heat-resistant copolymer and styrene-containing copolymer in the rubber-modified styrene-containing graft copolymer, but also a non-halogen-based flame retardant. By reducing the amount of added, the impact resistance and workability is excellent, mechanical properties and flame retardancy is excellent.

Claims (7)

a) iii) 10-50% by weight of rubber modified styrene containing graft copolymer; Ii) 20 to 70% by weight of copolymers polymerized with alpha methyl styrene and acrylonitrile; And Iii) 20 to 70% by weight of copolymers polymerized with styrene and acrylonitrile To 100 parts by weight of rubber-modified styrene resin containing b) as non-halogen flame retardant V) aromatic monophosphate and ii) aromatic diphosphate A rubber modified styrene resin composition comprising 4 to 15 parts by weight of aromatic phosphate, each containing 2 to 20 parts by weight with respect to 100 parts by weight of rubber modified styrene resin. The method of claim 1, 30 to 65 wt% of the rubber-modified styrene-containing graft copolymer of a) iii) selected from the group consisting of styrene, alphamethyl styrene, and nuclear substituted styrene in 10 to 60 wt% of rubber; And polybutadiene, styrene-butadiene copolymer, polyisoprene, and a grafted compound comprising 10 to 30% by weight of a compound selected from the group consisting of acrylonitrile, methyl methacrylate, and butyl acrylate. A rubber modified styrene resin composition selected from the group consisting of butadiene-isoprene copolymers. The method of claim 1, The rubber-modified styrene resin composition wherein the copolymer of a) ii) comprises 50 to 80% by weight of alpha methyl styrene and 20 to 50% by weight of acrylonitrile. The method of claim 1, The rubber-modified styrene resin composition of the said c) i) copolymer containing 50-80 weight% of styrene and 20-50 weight% of acrylonitrile. The method of claim 1, The aromatic monophosphate of b) ') is trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, trigy yl phosphate, cresyl diphenyl phosphate, which are not substituted with halogen, and Rubber modified styrene resin composition selected from the group consisting of octyl diphenyl phosphate. The method of claim 1, Rubber-modified styrene resin composition wherein the aromatic diphosphate of b) ii) is a compound represented by the following formula (1): [Formula 1] In the formula of Formula 1, Ar _{1 to} Ar ₄ is a phenyl group or an aryl group substituted with 1 to 3 alkyl groups of C _{1 to} C ₄ , R is phenyl or bisphenol a, n is an integer of 4-5. The method of claim 1, The rubber-modified styrene-based resin composition further comprises at least one additive selected from the group consisting of lubricants, heat stabilizers, antioxidants, light stabilizers, anti-drip agents, pigments, and inorganic fillers.