KR20000008555A - Flame retardant thermoplastic resin composition - Google Patents

Abstract

PURPOSE: A composition comprising polycarbonate resin, rubber denatured graft copolymer, vinyl copolymer, specific phosphorous oligomer derived from bisphenol-A. and fluorinated polyolefin is provided which stress-crack resistance, heat stability and anti shocking property. CONSTITUTION: The composition comprises (A)45-95 wt. parts of thermoplastic carbonate resin,; 5-95 wt. parts of monomer mixture of (B)50-95 wt. parts of (B-1)(B-1.1) styrene, alpha-methylstyrene, halogen or methyl ring-substituted styrene, C1-C8 methacrylic acid ester, anhydrous malefic acid, C1-C4 alkyl or its mixture, and 5-50 wt. parts of (B-1.2) acrylonitrile, methacrylonitrile, C1-C8 methacrylic acid alkylester, C1-C8 methacrylic acid ester, anhydrous maleic acid, C1-C4 alkyl or phenyl N-substituted maleimide or its mixture; 5-95 wt. parts of monomer mixture of 1-50 wt. parts of butadiene rubber, acrylic rubber, ethylene/propylene rubber, styrene/butadiene rubber, acrylonitrile/butadiene rubber, isoprene rubber, terpolymer(EPDM) of ethylene-propylene-diene, polyorganosiloxane/polyalkyl(metha)acrylate rubber composite; (C)50-95 wt, parts of (C-1)styrene, alpha-methylstyrene,, ring-substituted styrene, C1-C8 methacrylic acid alkylester, C1-C8 methacrylic acid ester, or its mixture. The composition is useful as a computer housing and other office instruments

Description

FLAME RETARDANT THERMOPLASTIC RESIN COMPOSITION

The present invention relates to a polycarbonate-based thermoplastic resin composition having excellent thermal stability and stress crack resistance that can be used in housings of electrical and electronic products, and more particularly, polycarbonate resins and rubber modified graphs. The present invention relates to a thermoplastic resin composition comprising a copolymer, a vinyl copolymer, a specific phosphorus oligomer compound, a fluorinated polyolefin, and a monomeric phosphorus compound.

Polycarbonate resins are excellent in transparency, mechanical strength and heat resistance, and are widely used in applications such as electric, electronic products, and automobile parts. However, polycarbonate resins are used in blends with other types of resins in order to improve them since they have disadvantages of poor processability. For example, blends of polycarbonate / styrene-containing copolymers are resin mixtures that improve processability while maintaining high notch impact strength.

In addition, since this polycarbonate resin composition is generally applied to a large heat dissipating material such as a computer housing or other office equipment, it is essential to maintain flame retardancy and high mechanical strength. In order to impart flame retardancy to such resin compositions, conventionally, halogen-based flame retardants and antimony compounds have been used. U.S. Patent Nos. 4,983,658 and 4,883,835 disclose examples of the use of halogen containing compounds as flame retardants. However, when halogen-based flame retardants are used, the demand for resins that do not contain halogen-based flame retardants has been rapidly expanded recently due to the problem of human health of gases generated during combustion.

As a technique for imparting flame retardancy without using a halogen flame retardant, the most common at present is to use a phosphate ester flame retardant. U.S. Patent No. 4,248,976 discloses a general formula of (a) phosphorus compounds and (b) R (CH ₂ X) _n in aromatic polymers such as styrene polymers and copolymers, aromatic polyesters, polycarbonate resins and polyphenylene oxides. Flame retardant compositions are disclosed using mixtures of compounds wherein R is an aromatic or heterocyclic group, X is a leaving group and n is at least two. However, when the phosphorus compound is used as a flame retardant, there is a problem in that a drip phenomenon of a flame occurs during combustion.

U.S. Patent No. 4,692,488 discloses thermoplastic resin compositions consisting of non-halogen aromatic polycarbonate resins, non-halogen SAN (styrene-acrylonitrile) copolymers, non-halogen phosphorus compounds, tetrafluoroethylene polymers and small amounts of ABS copolymers. It is described. The use of phosphorus-based compounds and fluorinated alkane polymers to impart flame retardancy to PC / ABS blend resin compositions, as in U.S. Patent No. 4,692,488, can prevent the dropping of sparks that occur during combustion. There is a problem in that the surface cracks, that is, the "juicing" phenomenon occurs by migrating to the surface of the molding.

U.S. Patent 5,030,675 discloses flame retardant resin compositions composed of aromatic polycarbonate resins, ABS copolymer resins and polyalkylene terephthalate resins, monomeric phosphoric acid esters and fluorinated polyolefins. However, the above composition has some disadvantages in that the stress crack resistance is somewhat improved, but the impact resistance is lowered and the thermal stability is sharply lowered at the time of processing at a high temperature.

Phosphoric acid ester oligomers are also known to be used as flame retardants, and Japanese Patent Laid-Open No. 59-202,240 discloses a process for preparing such compounds. It is also disclosed that this compound can be used as a flame retardant of polyamide or polycarbonate resins. However, the above patent does not show that the stress crack resistance is improved when the phosphate ester oligomer is used.

U. S. Patent No. 5,204, 394 discloses flame retardant resin compositions composed of aromatic polycarbonate resins, styrene-containing copolymers or graft copolymers, and phosphate ester oligomers. U. S. Patent No. 5,061, 745 discloses a flame retardant resin composition composed of aromatic polycarbonate resins, ABS graft copolymers, copolymers and monomeric phosphate esters. Phosphorus-based compounds used in the above patents are typically triarylphosphates and phosphate ester oligomers. Stress crack resistance in flame retardant resin compositions composed of aromatic polycarbonate resins, ABS graft copolymers and vinyl copolymers is mainly due to the volatility of the flame retardant, that is, the molecular weight of the flame retardant and the compatibility between the polycarbonate resin and the flame retardant. Is determined. In the case of using triaryl phosphate as a flame retardant, a 'juice' phenomenon occurs in which the flame retardant forms a laminae on the surface of the molded article due to volatilization of the flame retardant generated during molding. On the contrary, when the phosphate ester oligomer is used, the juice phenomenon due to volatilization of the flame retardant may be somewhat reduced. However, if the compatibility between the flame retardant and the polycarbonate resin is poor, the flame retardant may move to the surface of the molded article, resulting in surface cracking. In addition, due to the thermal stability of the resin composition due to the thermal decomposition of the phosphate ester oligomer, black stripe occurs on the surface of the injection molding.

U. S. Patent No. 5,672, 645 discloses PC / ABS resin compositions consisting of aromatic polycarbonate resins, vinyl copolymers, graft copolymers, mixtures of monomeric and oligomeric phosphate esters and fluorinated polyolefins. The patent uses resorcinol or hydroquinone derivatives as oligomeric phosphate esters, but the impact strength of the resin composition is poor because of the poor compatibility between these resorcinol or hydroquinone derived oligomeric phosphorus flame retardants and polycarbonate resins. There is a problem of deterioration. In addition, due to the decrease in compatibility, the flame retardant may move to the surface of the molding during molding, causing a surface crack problem, and black streaks are generated on the surface of the injection molding due to thermal decomposition of the resorcinol or hydroquinone-derived oligomeric phosphorus-based flame retardant.

The present inventors have diligently studied to solve the conventional problems, and as a result, polycarbonate resins, rubber modified graft copolymers, vinyl copolymers, phosphorus oligomeric compounds derived from bisphenol-A, fluorinated polyolefins and optionally As a result of constructing a monomeric phosphorus compound, it has been found that it is excellent in heat stability without occurrence of juice phenomenon and excellent in balance of physical properties such as flame retardancy, impact strength, heat resistance, workability and appearance, and the present invention. It was completed.

That is, an object of the present invention is a stress crack composed of polycarbonate resin, rubber modified graft copolymer, vinyl copolymer, specific phosphorus oligomeric compound derived from bisphenol-A, fluorinated polyolefin and optionally monomeric phosphorus compound It is to provide a thermoplastic resin composition excellent in resistance and thermal stability.

Another object of the present invention is to provide a thermoplastic resin composition having an excellent balance of physical properties such as flame retardancy, impact strength, heat resistance, workability and appearance.

The thermoplastic resin composition of the present invention

(A) 45 to 95 parts by weight of thermoplastic polycarbonate resin,

(B) (B-1) (B-1.1) styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters Or 50 to 95 parts by weight of a mixture thereof

(B-1.2) Acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N- 5 to 95 parts by weight of the monomer mixture consisting of 5 to 50 parts by weight of substituted maleimide or mixtures thereof

(B-2) The glass transition temperature is -10 ° C. or less, butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene terpolymer 1 to 50 parts by weight of a graft copolymer obtained by graft polymerization of 5 to 95 parts by weight of a polymer selected from one of EPEP, a polyorganosiloxane / polyalkyl (meth) acrylate rubber composite or a mixture thereof,

(C) (C-1) styrene, α- methyl styrene, ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters or a mixture thereof 50 to 95 wt. Wealth

(C-2) acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N- 0.5 to 50 parts by weight of a vinyl copolymer or a mixture of copolymers obtained by copolymerizing substituted maleimide or a mixture of 5 to 50 parts by weight of these,

(D) (D-1) 5 to 100% by weight of the oligomeric phosphate ester compound of the general formula (I)

Wherein R ₁ , R ₂ , R ₄ , and R ₅ are each C ₆ -C ₂₀ aryl or alkyl-substituted C ₆ -C ₂₀ aryl groups, R ₃ is a bisphenol-A derivative, and M is 0.1 to 3 Indicates the value of)

(D-2) 0-95 weight% of monomeric phosphate ester compounds which have the following general formula (II)

(Wherein, R is an alkyl group such as t-butyl, isopropyl, isobutyl, isoamyl, t-amyl, N represents an integer from 0 or 1 to 3.)

A mixture of phosphorus compounds having a content of 0.5 to 20 parts by weight relative to 100 parts by weight of the components (A) + (B) + (C), and

(E) Fluorinated polyolefins having an average particle size of 0.05 to 1000 µm and a density of 2.0 to 2.3 g / cm ³ based on 100 parts by weight of the component (A) + (B) + (C). It is characterized by consisting of resin.

Hereinafter, (A) polycarbonate resin, (B) rubber modified graft copolymer, (C) vinyl type copolymer, (D-1) phosphate ester oligomer which is each component of the thermoplastic resin composition of this invention (D- 2) A monomer type phosphate ester mixture and (E) fluorinated polyolefin resin are demonstrated in detail.

(A) polycarbonate resin

The aromatic polycarbonate resin, which is the component (A) used in the preparation of the resin composition of the present invention, is generally prepared by reacting diphenols represented by the following general formula (III) with phosgene, halogen formate or diester carbonate. Can be.

(Wherein A represents a single bond, C ₁ -C ₅ alkylene, C ₂ -C ₅ alkylidene, C _{5 to} C ₆ cycloalkylidene, -S- or -SO _2- )

Specific examples of the diphenol of the general formula (III) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis- (4-hydroxyphenyl) -propane, 2,4-bis -(4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (4-hydroxyphenyl) -cyclohexane, 2,2-bis- (3-chloro-4-hydroxyphenyl) -propane And 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane. Among them, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 1,1-bis- (4- Hydroxyphenyl) -cyclohexane and the like are preferable. More preferred and most industrially used aromatic polycarbonates are prepared from 2,2-bis- (4-hydroxyphenyl) -propane, also called bisphenol-A.

Suitable polycarbonates used in the production of the resin composition of the present invention include those having a weight average molecular weight of 10,000 to 200,000, preferably 15,000 to 80,000.

As the polycarbonate used in the preparation of the resin composition of the present invention, a branched chain may be used. Preferably, 0.05 to 2 mol% of a tri- or more polyfunctional compound is used with respect to the total amount of diphenols used for polymerization. For example, it can manufacture by adding the compound which has a trivalent or more phenol group.

Examples of polycarbonates used in the preparation of the resin composition of the present invention include homopolycarbonates and copolycarbonates. Also, the polycarbonates may be used in the form of a blend of copolycarbonates and polycarbonates. It is possible.

In addition, the polycarbonate used in the preparation of the resin composition of the present invention may be partially or entirely replaced by an aromatic polyester-carbonate resin obtained by polymerizing in the presence of an ester precursor, such as a bifunctional carboxylic acid. Do.

(B) graft copolymer

The graft copolymer (B) used in the preparation of the resin composition of the present invention is (B-1.1) styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, 50 to 95 parts by weight of C ₁ -C ₈ methacrylic acid esters or mixtures thereof, (B-1.2) acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C _{8 to} 95 parts by weight of the monomer mixture (B-1) consisting of 5 to 50 parts by weight of ₈ methacrylic acid ester, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N-substituted maleimide or mixtures thereof, and the glass transition temperature Butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene monomer terpolymer (EPDM) rubber, polyorganosiloxane / As polyalkyl (meth) acrylate rubber composite Luer binary group alone or in combination of two or more polymers (B-2) is selected from 5 to 95 parts by weight is obtained by the graft polymerization.

The C ₁ -C ₈ methacrylic acid alkyl esters or C ₁ -C ₈ acrylic acid alkyl esters are monohydryl alcohols each containing 1 to 8 carbon atoms as esters of acrylic acid or methacrylic acid, respectively. As these specific examples, methacrylic acid methyl ester, methacrylic acid ethyl ester, or methacrylic acid propyl ester are mentioned, Among these, methacrylic acid methyl ester is especially preferable.

Preferred examples of the graft copolymer (B) include those obtained by graft copolymerization of styrene, acrylonitrile and (meth) acrylic acid alkyl ester monomers alone or in a mixture with butadiene rubber, acrylic rubber, or styrene / butadiene rubber. . More preferred graft copolymers (B) are ABS copolymers.

The particle diameter of the rubber (B.2) is preferably used in the 0.05 ~ 4㎛ to improve the impact strength and the molding surface.

The method for preparing the graft copolymer is well known to those skilled in the art, and any one of emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization may be used, and a preferred manufacturing method For example, the above-mentioned aromatic vinyl monomer is introduced in the presence of a rubbery polymer, followed by emulsion polymerization or bulk polymerization using a polymerization initiator.

(C) vinyl copolymer

Examples of the vinyl copolymer (C) used in the preparation of the resin composition of the present invention include (C-1) styrene, α-methylstyrene, ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, and C ₁ − 50 to 95 parts by weight of C ₈ methacrylic acid esters or mixtures thereof (C-2) acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ alkyl acrylate And vinyl copolymers obtained by copolymerizing 5 to 50 parts by weight of esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N-substituted maleimides or mixtures thereof, or mixtures of these copolymers.

The C ₁ -C ₈ methacrylic acid alkyl esters or C ₁ -C ₈ acrylic acid alkyl esters are monohydryl alcohols having 1 to 8 carbon atoms as esters of acrylic acid or methacrylic acid, respectively. As these specific examples, methacrylic acid methyl ester, methacrylic acid ethyl ester, or methacrylic acid propyl ester are mentioned, Among these, methacrylic acid methyl ester is especially preferable.

The thermoplastic vinyl copolymer (C) used in the preparation of the resin composition of the present invention can be produced as a by-product in the preparation of the graft copolymer (B), and in particular, an excessive amount of vinyl monomer in a small amount of rubbery polymer In the case of grafting, more occurs. The content of the copolymer (C) used in the preparation of the resin composition of the present invention does not include a by-product of the graft copolymer (B).

The copolymer (C) used in the production of the resin composition of the present invention is a thermoplastic resin and does not contain rubber.

As a preferable copolymer (C), the thing manufactured by emulsion polymerization, suspension polymerization, solution polymerization, or block polymerization using methacrylic acid methyl ester and (meth) acrylic acid methyl ester is mentioned.

Other preferred copolymers (C) include monomer mixtures of styrene and acrylonitrile and optionally methyl methacrylate, monomer mixtures of α-methylstyrene and acrylonitrile and optionally methyl methacrylate or styrene, α-methyl And those prepared from monomer mixtures of styrene and acrylonitrile and optionally methacrylic acid methylester. The styrene / acrylonitrile copolymer as component (C) may be prepared by emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization, and it is preferable to use those having a weight average molecular weight of 15,000 to 200,000.

Another preferred copolymer (C) used in the preparation of the resin composition of the present invention is a copolymer of styrene and maleic anhydride, which can be produced using a continuous bulk polymerization method and a solution polymerization method. The composition ratio of the two monomer components can be varied in a wide range, preferably, the content of maleic anhydride is 5 to 25% by weight. The molecular weight of the styrene / maleic anhydride copolymer as copolymer (C) may also be a wide range, but it is preferable to use those having a weight average molecular weight of 60,000 to 200,000 and intrinsic viscosity of 0.3 to 0.9.

The styrene monomers used in the preparation of the vinyl copolymer (C) used in the preparation of the resin composition of the present invention are other substituted styrenes such as p-methylstyrene, vinyltoluene, 2,4-dimethylstyrene and α-methylstyrene. It can be used instead of the monomer.

The vinyl copolymer (C) used in the production of the resin composition of the present invention described above is used alone or in a mixture of two or more thereof.

(D-1) Oligomeric Phosphate Ester Compound

In the resin composition of the present invention, a mixture of a flame retardant is used as two flame retardants, an oligomeric phosphate ester (D-1) and a monomeric phosphate ester mixture (D-2).

Component (D-1) is an oligomeric phosphate ester compound represented by the following general formula (I).

Wherein R ₁ , R ₂ , R ₄ and R ₅ are each C ₆ -C ₂₀ aryl or alkyl-substituted C ₆ -C ₂₀ aryl groups, R ₃ is a bisphenol-A derivative and M is a value of 0.1 to 3. Indicates.

The compound of the above general formula is an oligomeric phosphate ester. That is, the flame retardant component (D-1) used in the preparation of the resin composition of the present invention is an oligomeric phosphate ester having a M value of 0.1 to 3.

The use of an oligomeric phosphate ester derived from bisphenol-A as a flame retardant improves the compatibility with polycarbonate resins and provides better thermal stability than an oligomeric phosphate ester derived from resorcinol or hydroquinone. The stress crack resistance, impact strength, flame retardancy, and thermal stability of the composition are excellent.

(D-2) Monomer Type Phosphate Ester Mixture

The component (D-2) used for manufacture of the resin composition of this invention is a mixture of the monomeric phosphate ester compound which has the following general formula (II).

In the above formula, R is an alkyl group such as t-butyl, isopropyl, isobutyl, isoamyl, t-amyl and the like, and N represents an integer from 0 or 1 to 3.

Preferably, component (D-2) comprises 0-20% by weight of tri (alkylphenyl) phosphate (N = 3), 0-50% by weight of di (alkylphenyl) monophenylphosphate (N = 2), It is preferred that it is a mixture of alkylsubstituted monophosphates composed of 0-60% by weight of diphenylmono (alkylphenyl) phosphate (N = 1) and 0-100% by weight of triphenylphosphate (N = 0).

Preferred substituents R include t-butyl and isopropyl, and more preferably t-butyl. Moreover, it is also preferable to use together the mixture of t-butylphenyl phosphate, and the mixture of isopropyl phenyl phosphate.

The thermoplastic resin composition of the present invention uses (D-1) and (D-2) in combination as a flame retardant, and their weight ratio can be varied in a wide range. Preferably, 5 to 100% by weight of (D-1) and 95 to 0% by weight of (D-2) are used, and 10 to 90% by weight of (D-1) and 90 to 10% by weight It is more preferable to use (D-2).

(E) fluorinated polyolefin resin

The fluorinated polyolefin resin (E) used in the preparation of the thermoplastic resin composition of the present invention is conventionally available resins such as polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, Tetrafluoroethylene / hexafluoropropylene copolymer, ethylene / tetrafluoroethylene copolymer, etc. are mentioned. These may be used independently from each other, and two or more different types may be used together.

When the fluorinated polyolefin resin is mixed and extruded together with the other component resins of the present invention, a fibrillar network is formed in the resin to lower the flow viscosity of the resin during combustion and increase the shrinkage rate to increase the shrinkage. To prevent.

The fluorinated resin used in the preparation of the resin composition of the present invention may be prepared using a known polymerization method, for example, a pressure of ^{7 to} 71 kg / cm ² and a temperature of 0 to 200 ℃, preferably 20 to It can be prepared in an aqueous medium containing a free radical forming catalyst such as sodium, potassium or ammonium peroxydisulfate at 100 ° C.

The fluorinated polyolefin resin may be used in an emulsion state or a powder state. When the fluorinated polyolefin resin in an emulsion state is used, the dispersibility in the entire resin composition is good, but the manufacturing process is complicated. Therefore, even if it is powder state, if it can disperse | distribute suitably in the whole resin composition and can form a fibrous network, it is preferable to use it in powder state.

Fluorinated polyolefin-based resins which can be preferably used for the preparation of the resin composition of the present invention include polytetrafluoroethylene having a particle size of 0.05 to 1,000 µm and specific gravity of 2.0 to 2.3 g / cm ² .

The content of the fluorinated polyolefin resin used in the preparation of the resin composition of the present invention is 0.05 to 5 parts by weight based on 100 parts by weight of the base resin component (A) + (B) + (C).

The thermoplastic resin composition of the present invention may include general additives such as lubricants, mold release agents, nucleating agents, antistatic agents, stabilizers, reinforcing agents, inorganic additive pigments or dyes according to their respective applications, in addition to the above components. It can be used in the range of 0 to 60 parts by weight, preferably 10 to 40 parts by weight based on 100 parts by weight of the base resin component (A) + (B) + (C).

The 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 prepared in pellet form.

The compositions of the present invention can be used in the molding of various products, and are particularly suitable for the manufacture of housings of electrical and electronic products, such as computer housings, where high impact strength and stress crack resistance are required.

EXAMPLE

Hereinafter, the present invention will be described in detail by way of examples to be described later. However, the scope of the present invention is not limited by these examples.

(A) polycarbonate resin

A polycarbonate of bisphenol-A type having a weight average molecular weight (MW) of 20,000 was used.

(B) rubber modified graft copolymer

Butadiene rubber latex was added so that the butadiene content was 45 parts by weight based on the total amount of monomers, 1.0 parts by weight of potassium oleate, cumene hydroperoxide, which was an additive necessary for a mixture of 36 parts by weight of styrene, 14 parts by weight of acrylonitrile, and 150 parts by weight of deionized water. 0.4 parts by weight, 0.3 parts by weight of mercaptan-based chain transfer agent was added to the reaction while maintaining at 75 ℃ for 5 hours to prepare an ABS graft latex. A 1% sulfuric acid solution was added to the resulting polymer latex, and after coagulation, dried to prepare a graft copolymer resin in a powder state.

(C) vinyl copolymer resin

A SAN copolymer resin was prepared by suspension polymerization by adding 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of tricalcium phosphate, which are necessary additives to a mixture of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile, and 120 parts by weight of deionized water. . The copolymer was washed with water, dehydrated and dried to obtain a SAN copolymer resin in powder form.

(D-1) Oligomeric Phosphate Ester Compound

Bisphenol-A diphenylphosphate having an average M value of 1.3 in General Formula (I) was used.

(D-2) Monomer Phosphoric Acid Ester Compound

(D-2.1) Triphenylphosphate (TPP) was used.

(D-2.2) 0.5 wt% triphenylphosphate, 33.2 wt% diphenylmono (t-butylphenyl) phosphate, 49.5 wt% di (t-butylphenyl) monophenyl phosphate and 12.5 wt% tri (t A mixture of t-butyl substituted monophosphates consisting of -butylphenyl) phosphate was used.

(E) fluorinated polyolefin resin

Teflon (trade name) 7AJ of Dupont, USA was used.

Calculation of solubility parameter

In order for the two different components to show compatibility, the solubility index of each component must not differ significantly. Solubility indices are generally divided into three categories, each of which is:

δ _d = Influence by dispersion force

δ _p = Influence by polar force

δ _h = effect by hydrogen bonding

The compatibility of the two components can finally be determined by the following determinant Δδ.

Δδ ² = (δ _d1 -δ _d2 ) ² + (δ _p1 -δ _p2 ) ² + (δ _h1 -δ _h2 ) ²

To be compatible, the value of Δδ must be small.

The solubility index of the flame retardants used in the preparation of the resin composition of the present invention can be calculated by Group Contribution Theory of "Hoftyzer and VanKrevelen", these values are shown in Table 1.

As shown in Table 1, bisphenol-A diphenyl phosphate, the component (D-1) used in the preparation of the resin composition of the present invention, has the best compatibility with polycarbonate resins than other flame retardants. Therefore, it can be expected that the polycarbonate-based resin composition using bisphenol-A diphenyl phosphate as a flame retardant may exhibit better stress crack resistance and mechanical properties, that is, impact strength than a composition using resorcinol diphenyl phosphate.

Table 1

δ _d δ _p δ _h Δδ ^* (A) polycarbonate resin 21.79 3.73 7.57 - (D-1) Bisphenol-A diphenyl phosphate 21.27 5.44 7.25 1.82 Resorcinol Diphenyl Phosphate ^** 21.50 6.81 8.12 3.14 (D-2.1) triphenyl phosphate 20.77 7.84 7.33 4.24 (D-2.2) t-butyl substituted monophosphate (N = 1) 19.23 5.87 6.34 3.56 (D-2.2) t-butyl substituted monophosphate (N = 2) 18.31 4.69 5.67 4.08 (D-2.2) t-butyl substituted monophosphate (N = 3) 17.69 3.91 5.17 4.75

Δδ means the difference between the polycarbonate resin and the flame retardant (D)

** Resorcinol diphenyl phosphate was evaluated as a comparative flame retardant of bisphenol-A diphenyl phosphate of (D-1) of the present invention

Flame Retardant Stability

The volatility and thermal stability of the flame retardant were evaluated by measuring weight loss using TGA (Thermal Gravimetric Analysis). The specimen was placed in an open aluminum cell, and the mass loss was measured at a rate of 10 ° C./min from 350 ° C. to 350 ° C. under a nitrogen atmosphere, and the weight loss rates measured at three different temperatures are shown in Table 2. As shown in Table 2, it can be seen that the volatility and thermal stability of the bisphenol-A diphenyl phosphate component (D-1) used in the preparation of the resin composition of the present invention is much superior to other flame retardants.

TABLE 2

250 ℃ 300 ℃ 350 ℃ (D-1) Bisphenol-A diphenyl phosphate 0.5% 2.2% 6.6% Resorcinol Diphenyl Phosphate 0.5% 2.5% 10.7% (D-2.1) triphenyl phosphate 9.2% 56.4% 85.1%

In addition, the hydrolysis characteristics of each flame retardant were measured by the following method; 250 g of flame retardant was poured into a beaker and left for 96 hours under saturated steam at 120 캜 and 2 atmospheres. After drying the residual moisture, the change in weight and the change in acid value were measured, which are given in Table 3. As can be seen from the results of Table 3, in the case of bisphenol-A diphenyl phosphate, the acid value and weight increase measured after the test are the smallest, and it can be seen that this shows the best hydrolysis property.

TABLE 3

Acid value before test (mgKOH / g) Acid value after test (mgKOH / g) Weight after test (g) Weight increase rate after test (%) (D-1) Bisphenol-A diphenyl phosphate 3.0 121 258 3.2 Resorcinol Diphenyl Phosphate 0.03 330 292 16.7 (D-2.1) triphenyl phosphate 0.01 215 277 10.8

From the results of Tables 1, 2 and 3 above, bisphenol-A diphenyl phosphate as the component (D-1) of the present invention has the best compatibility with the polycarbonate resin, and has thermal stability and hydrolysis resistance. It can be seen that also excellent compared to other flame retardants.

Examples 1-7

Seven kinds of resin compositions were prepared by using the aforementioned components as shown in Table 4, and their physical properties are also shown in Table 4.

Each component, antioxidant, and heat stabilizer were added, mixed in a conventional mixer, extruded using a twin screw extruder having L / D = 35 and Φ = 45 mm, and then the extrudate was manufactured in pellet form. Specimens were prepared for measurement of physical properties at ℃. These specimens were measured for 40 hours at 23 ° C. and 50% relative humidity, and then measured for physical properties according to ASTM standards.

In order to observe the stress crack characteristics, the rectangular container-shaped specimens were left in a heating oven at 80 ° C. for 24 hours, and then the number and length of cracks generated at the inner and outer surfaces were measured. Square container-shaped specimens were prepared by injecting specimens having a width, length, height, and thickness of 200, 200, 100, and 3 mm, respectively, at a temperature of 250 ° C. using a 40-ounce injection machine.

The thermal stability of the resin composition was judged as the occurrence of black streak appearing on the surface of the injection molding when a 200 mm × 50 mm × 2 mm size flat plate was injected. Injection temperature was varied in the range of 260 ~ 300 ℃, and evaluated while changing the injection pressure and speed.

Comparative Examples 1-7

Comparative Examples 1 to 7 were prepared by adding resorcinol diphenyl phosphate or triphenyl phosphate to the same resin composition as Examples 1 to 7 instead of (D-1) bisphenol-A diphenyl phosphate used as a flame retardant. As a result, the composition and the measurement result of the physical property are shown in Table 5.

From the results of Tables 4 and 5, when an oligomeric phosphate ester flame retardant derived from bisphenol-A is used, higher impact strength and heat resistance than when using resorcinol-derived oligomeric phosphate ester flame retardant or triphenylphosphate flame retardant Very high stress crack resistance and thermal stability. This result shows that bisphenol-A diphosphate flame retardant shows much better stability than other flame retardants and the difference in solubility index (Δδ) between bisphenol-A diphosphate and polycarbonate resin is different from other flame retardants and polycarbonate. This is consistent with the smaller results.

Table 4

Example One 2 3 4 5 6 7 (A) polycarbonate resin 65 67 67 63 78 71 71 (B) graft copolymer 7.7 10.65 10.65 12 9 9 9 (C) vinyl copolymer 15 10 10 15 3 9 9 (D-1) Bisphenol-A diphenyl phosphate 12 7 8 10 10 7.1 5.2 (D-2.1) triphenyl phosphate - 3 2 - - - 2.7 (D-2.2) mixture of t-butyl substituted monophosphate - - - - - 3.5 2.7 (E) fluorinated polyolefins 0.3 0.35 0.35 0.2 0.2 0.4 0.4 UL 94 (1/16 ") ⁽¹⁾ V-0 V-0 V-0 V-0 V-0 V-0 V-0 Izod impact strength ⁽²⁾ (1/8 ", kgcm / cm) 33 41 43 37 49 43 42 Heat resistance (VST, ℃) ⁽³⁾ 97 96 97 93 104 97 94 Number of cracks ⁽⁴⁾ 2 4 3 One 2 4 5 Full length of the crack (mm) ⁽⁵⁾ 2.1 12.9 9.9 1.2 1.9 11.4 18.1 Thermal Stability (Black Stripes) ⁽⁶⁾ ○ ○ ○ ○ ○ ○ ○

⁽¹⁾ UL 94 (1/16 ") is rated according to UL 94 VB

⁽²⁾ Izod impact strength is evaluated according to ASTM D256

⁽³⁾ Heat resistance is evaluated according to ASTM D306

⁽⁴⁾ shows the number of cracks on the surface of the injection molding

⁽⁵⁾ shows the total length of cracks on the surface of the injection molding

⁽⁶⁾ thermal stability

O = no black streaks observed

△ = black streaks sometimes appear depending on injection conditions

× = black lines frequently appear

Table 5

Comparative example 1A 1B 2 3 4 5 6 7 (A) polycarbonate resin 65 65 67 67 63 78 71 71 (B) graft copolymer 7.7 7.7 10.65 10.65 12 9 9 9 (C) vinyl copolymer 15 15 10 10 15 3 9 9 Resorcinol Diphenyl Phosphate - 12 7 8 10 10 7.1 5.2 (D-2.1) triphenyl phosphate 12 - 3 2 - - - 2.7 (D-2.2) mixture of t-butyl substituted monophosphate - - - - - - 3.5 2.7 (E) fluorinated polyolefins 0.3 0.3 0.35 0.35 0.2 0.2 0.4 0.4 UL 94 (1/16 ") ⁽¹⁾ V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 Izod impact strength ⁽²⁾ (1/8 ", kgcm / cm) 15 13 31 30 34 32 38 36 Heat resistance (VST, ℃) ⁽³⁾ 85 93 92 93 89 100 94 92 Number of cracks ⁽⁴⁾ 36 6 8 7 5 6 7 10 Full length of the crack (mm) ⁽⁵⁾ 115.7 20.9 33.7 27.6 18.6 23.4 30.8 40.4 Thermal Stability (Black Stripes) ⁽⁶⁾ ○ × × × × × × △

⁽¹⁾ UL 94 (1/16 ") is rated according to UL 94 VB

⁽²⁾ Izod impact strength is evaluated according to ASTM D256

⁽³⁾ Heat resistance is evaluated according to ASTM D306

⁽⁴⁾ shows the number of cracks on the surface of the injection molding

⁽⁵⁾ shows the total length of cracks on the surface of the injection molding

⁽⁶⁾ thermal stability

O = no black streaks observed

△ = black streaks sometimes appear depending on injection conditions

× = black lines frequently appear

The flame-retardant thermoplastic resin composition according to the present invention is excellent in thermal stability without the occurrence of juice phenomenon, excellent balance of physical properties such as flame retardancy, impact strength, heat resistance, workability and appearance, and excellent stress crack resistance of the computer housing It is useful for producing injection moldings of other office equipment.

Claims (11)

(A) 45 to 95 parts by weight of thermoplastic polycarbonate resin, (B) (B-1) (B-1.1) styrene, α-methylstyrene, halogen or methyl ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters Or 50 to 95 parts by weight of a mixture thereof (B-1.2) Acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N- 5 to 95 parts by weight of the monomer mixture consisting of 5 to 50 parts by weight of substituted maleimide or mixtures thereof (B-2) The glass transition temperature is -10 ° C. or less, butadiene rubber, acrylic rubber, ethylene / propylene rubber, styrene / butadiene rubber, acrylonitrile / butadiene rubber, isoprene rubber, ethylene-propylene-diene terpolymer 1 to 50 parts by weight of a graft copolymer obtained by graft polymerization of 5 to 95 parts by weight of a polymer selected from one of EPEP, a polyorganosiloxane / polyalkyl (meth) acrylate rubber composite or a mixture thereof, (C) (C-1) styrene, α- methyl styrene, ring-substituted styrene, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters or a mixture thereof 50 to 95 wt. Wealth (C-2) acrylonitrile, methacrylonitrile, C ₁ -C ₈ methacrylic acid alkyl esters, C ₁ -C ₈ methacrylic acid esters, maleic anhydride, C ₁ -C ₄ alkyl or phenyl N- 0.5 to 50 parts by weight of a vinyl copolymer or a mixture of copolymers obtained by copolymerizing substituted maleimide or a mixture of 5 to 50 parts by weight of these, (D) (D-1) 5 to 100% by weight of the oligomeric phosphate ester compound of the general formula (I) Wherein R ₁ , R ₂ , R ₄ , and R ₅ are each C ₆ -C ₂₀ aryl or alkyl-substituted C ₆ -C ₂₀ aryl groups, R ₃ is a bisphenol-A derivative, and M is at 0.1 Indicates a value of 3.) (D-2) 0-95 weight% of monomeric phosphate ester compounds which have the following general formula (II) (Wherein, R is an alkyl group, such as t-butyl, isopropyl, isobutyl, isoamyl, t-amyl, N represents an integer from 0 or 1 to 3.) A mixture of phosphorus compounds having a content of 0.5 to 20 parts by weight relative to 100 parts by weight of the components (A) + (B) + (C), and (E) Fluorinated polyolefins having an average particle size of 0.05 to 1000 µm and a density of 2.0 to 2.3 g / cm ³ based on 100 parts by weight of the component (A) + (B) + (C). Suzy Flame retardant thermoplastic resin composition, characterized in that consisting of. The flame retardant thermoplastic resin composition according to claim 1, wherein the weight ratio of the components (D-1) and (D-2) has a value of 10:90 to 90:10. A flame retardant thermoplastic resin composition according to Claim 1, wherein R ₁ , R ₂ , R ₄ and R ₅ of component (D-1) are phenyl groups. The flame retardant thermoplastic resin composition according to claim 1, wherein the component (D-1) is bisphenol-A diphenylphosphate derived from bisphenol-A. The composition (D-2) according to claim 1, wherein the component (D-2) is 0 to 20% by weight of tri (alkylphenyl) phosphate (N = 3), 0 to 50% by weight of di (alkylphenyl) monophenylphosphate (N = 2). ), A mixture of alkyl substituted monophosphate consisting of 0 to 60% by weight of diphenylmono (alkylphenyl) phosphate (N = 1) and 0 to 100% by weight of triphenylphosphate (N = 0). Flame retardant thermoplastic resin composition. A flame retardant thermoplastic resin composition according to Claim 1, wherein R of component (D-2) is a t-butyl group. The flame retardant thermoplastic resin composition according to claim 1, wherein R of the component (D-2) is an isopropyl group. The method of claim 1, wherein the resin composition further comprises inorganic additives, glass fibers, carbon fibers, heat stabilizers, antioxidants, light stabilizers, plasticizers, pigments, dyes, lubricants and mold release agents, fillers, nucleating agents and antistatic agents. Flame retardant thermoplastic resin composition. (A) 45 to 95 parts by weight of thermoplastic polycarbonate resin, (B) 2 to 40 parts by weight of a graft copolymer obtained by graft polymerization of styrene and acrylonitrile monomers into crosslinked butadiene rubber, (C) 1 to 40 parts by weight of styrene / acrylonitrile copolymer, (D) 5 to 100% by weight of bisphenol-A diphenylphosphate relative to (D-1) (D), (D-2) 95 to 0 wt% of triphenylphosphate relative to (D) A mixture of 2 to 20 parts by weight based on 100 parts by weight of the component (A) + (B) + (C), and (E) Flame retardant thermoplastic resin having excellent stress crack resistance and thermal stability, comprising 0.05 to 5 parts by weight of tetrafluoroethylene resin with respect to 100 parts by weight of component (A) + (B) + (C). Composition. (A) 45 to 95 parts by weight of thermoplastic polycarbonate resin, (B) 2 to 40 parts by weight of a graft copolymer obtained by graft polymerization of styrene and acrylonitrile monomers into crosslinked butadiene rubber, (C) 1 to 40 parts by weight of styrene / acrylonitrile copolymer, (D) 10 to 90% by weight of bisphenol-A diphenylphosphate relative to (D-1) (D), (D-2) 90 to 10% by weight of triphenylphosphate relative to (D) A mixture of 2 to 20 parts by weight based on 100 parts by weight of the component (A) + (B) + (C), and (E) Flame retardant thermoplastic resin having excellent stress crack resistance and thermal stability, comprising 0.05 to 5 parts by weight of tetrafluoroethylene resin with respect to 100 parts by weight of component (A) + (B) + (C). Composition. The method according to claim 10, wherein 50 to 90 parts by weight (A), 3 to 30 parts by weight (B), 2 to 30 parts by weight (C), 3 to 18 parts by weight (D) and 0.1 to 2.0 parts by weight (E) Flame retardant thermoplastic resin composition, characterized in that consisting of.