DE19842713B4 - Thermoplastic resin composition - Google Patents

Abstract

worin R eine Alkylgruppe ist, ausgewählt aus t-Butyl-, Isopropyl-, Isobutyl-, Isoamyl-, t-Amyl-Gruppen, und N 0 oder eine ganze Zahl von 1 bis 3 ist.Thermoplastic resin composition with
(A) 40 to 95 parts by weight of a halogen-free thermoplastic polycarbonate;
(B) 5 to 50 parts by weight of a styrene-containing graft copolymer prepared by grafting (B-1) to (B-2)
(B-1) 5 to 95% by weight, based on (B), of styrene, α-methylstyrene, nucleus-substituted styrene, methyl methacrylate or a mixture thereof
(B-2) 95 to 5% by weight, based on (B), of a rubber having a glass transition temperature (Tg) lower than -10 ° C and selected from the group consisting of butadiene, acrylic, ethylene / propylene -, styrene / butadiene, acrylonitrile / butadiene, butadiene / styrene rubbers, polyisoprene, EPDM rubber, polyorganosiloxane and mixtures thereof;
(D) 5 to 20 parts by weight, based on 100 parts by weight of (A) + (B) comprising
(D-1) a mixture of alkyl-substituted monophosphate esters of the formula (I)

wherein R is an alkyl group selected from t-butyl, isopropyl, isobutyl, isoamyl, t-amyl groups, and N is 0 or an integer of 1 to 3.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The This invention relates to flame retardant thermoplastic resin compositions. In particular, the invention relates to thermoplastic resin compositions, a polycarbonate, a styrene-containing graft copolymer, optionally a styrene-containing copolymer, a mixture of alkyl substituted, preferably t-butyl substituted monophosphate esters, optionally a phosphate ester compound and optionally a fluorinated one Include polyolefin, its stress crack resistance and flame retardancy or improved flame retardancy are.

Discussion of the state of technology

Polycarbonate resin compositions will be far for Parts of electrical products and motor vehicle components used as it has a good combination of transparency, high impact resistance and heat resistance demonstrate. However, polycarbonate resin compositions have a poor accessibility while of the molding process, so that polycarbonate resin compositions are usually mixed with other resins to improve these properties become. For example, a molding composition containing a Polycarbonate resin and a styrene resin, a good processability as well as a high notched impact strength.

Of Further, polycarbonate molding compounds should be used for parts home and office applications be used, flame resistant be to prevent fire.

In order to impart flame retardancy to thermoplastic molding compounds, halogen and / or antimony-containing compounds have been incorporated. In the U.S. Patents 4,983,658 and 4,883,835 For example, a halogen-containing compound is used as a flame retardant. However, the halogen-containing compound causes corrosion of the mold itself by the hydrogen halide gases released during the molding process, and causes fatal injury due to toxic gases released in the event of fire.

When a method to flame retardancy without using a flame retardant It is common to lend on the basis of halogens a method which uses a flame retardant or flame retardant used on the basis of a phosphate ester. The use of halogen-free Phosphate ester compounds as flame retardants avoids the Problems caused by the corrosive and harmful byproducts of flame retardant Funds are caused on the basis of halogen. However, they tend to Flame retardants based on phosphate esters to cause a deterioration of the heat resistance, the Occurrence of stress cracks due to volatilization of the flame retardant Means and so-called "sticking" during the Forming process favor.

To overcome these problems describes the Japanese Patent Publication No. (Sho) 62-25706 the use of a mixture of an aryl phosphate ester prepared by reacting phosphorus oxychloride with a dihydric phenol and a monohydric phenol, and an oligomeric phosphate ester as a flame retardant. In this method, however, the flame retardant prepared in this manner is caused by the phosphorus oxychloride and a residual metal ion derived from a metal salt used as a catalyst, such as aluminum chloride, magnesium chloride, etc., for corrosion of the mold itself.

U.S. Patents 5,061,745 and 5,030,675 describe polymer blends made from an aromatic polycarbonate, an ABS graft copolymer, a styrene-containing copolymer, a monophosphate ester such as triphenyl phosphate (TPP) as a flame retardant, and a fluorinated polyolefin. However, the low stress cracking resistance of these molding compositions limits the use of non-halogen PC / ABS in the field of making parts of electronic and electrical products, especially thin-walled parts. Likewise, the heat resistance of these mixtures deteriorates significantly.

To avoid the occurrence of stress cracks and the deterioration of heat resistance at Ver reducing the use of a monophosphate ester describes this U.S. Patent 5,204,394 a polymer blend comprising an aromatic polycarbonate, a styrene-containing copolymer and / or a styrene-containing graft copolymer, and an oligomer phosphate flame retardant. With this polymer blend, it is possible to obtain a VO rating according to UL-94 using the oligomer phosphate whose condensation degree is about 1.4. However, when the degree of condensation of the oligomer phosphate exceeds 2.8, the flame retardancy of this polymer blend rapidly decreases to HE value, and the stress cracking resistance of the mixture decreases.

U.S. Patent 5,672,645 describes flame retardant polycarbonate / ABS molding compositions whose stress cracking resistance is improved by means of a combination of additives comprising monomeric phosphorus compounds and an oligomer phosphorus compound compared to molding compositions containing only a monophosphorus compound and an oligomer phosphorus compound, respectively. However, heat resistance and stress cracking resistance of these compositions are insufficient, so that improvement is required.

U.S. Patent 5,206,404 describes compositions with alkylated triphenyl phosphate esters which contain from 1 to 20% by weight of trialkylphenyl phosphate, from 10 to 50% by weight of dialkylphenylmonophenyl phosphate, from 15 to 60% by weight of monoalkylphenyldiphenyl phosphate and less than 2% by weight of triphenyl phosphate. However, this publication contains no indication of an improvement in the stress cracking resistance and the flame retardancy of thermoplastic resin compositions with the addition of these mixtures of triaryl phosphate esters.

The invention is based on the discovery that flame retardant thermoplastic resin compositions excellent in stress cracking resistance and heat resistance can be prepared by using flame retardants comprising a phosphate ester and a mixture of alkyl substituted, preferably t-butyl substituted monophosphate esters according to U.S. Pat US-A 5,206,404 include, adds. The flame-retardant thermoplastic resin compositions of the present invention exhibit good stress cracking resistance and increased heat resistance compared to the molding compound according to the present invention US-A 5,672,645 containing, as a flame retardant, a monophosphorus compound and an oligomer phosphorus compound.

Object of the invention

task The invention is a flame retardant thermoplastic resin composition with excellent resistance to stress cracking and improved heat resistance which is a polycarbonate, a styrene-containing graft copolymer, optionally a styrene-containing copolymer, a mixture of alkyl-substituted, preferably t-butyl substituted Monophosphate esters, optionally a phosphate ester and optionally a fluorinated polyolefin.

Summary of the invention

• (A) 40 bis 95 Gew.-Teile eines halogenfreien thermoplastischen Polycarbonats;
• (B) 5 bis 50 Gew.-Teile eines styrolhaltigen Pfropfcopolymers, das durch Pfropfen von (B-1) auf (B-2) hergestellt wurde, wobei
• (B-1) 5 bis 95 Gew.-%, bezogen auf (B), einer Mischung von
• (B-1.1) 50 bis 100 Gew.-% an Styrol, α-Methylstyrol, kernsubstituiertes Styrol, Methylmethacrylat oder eine Mischung davon, und
• (B-1.2) 50 bis 0 Gew.-% Acrylnitril, Methacrylnitril, C₁-C₈-Alkylmethacrylat, C₁-C₈-Alkylacrylat, Maleinsäureanhydrid, N-substituiertes Maleinimid oder eine Mischung davon ist, und
• (B-2) 95 bis 5 Gew.-%, bezogen auf (B), eines Kautschuks mit einer Glasübergangstemperatur (Tg) von weniger als –10°C und aus der Gruppe ausgewählt ist, bestehend aus Butadienkautschuken, Acrylkautschuken, Ethylen/Propylen- Kautschuken, Styrol/Butadienkautschuken, Acrylnitril/Butadienkautschuken, Butadien/Styrolkautschuken, Polyisopren, EPDM(Ethylen-propylen-dien-terpolymer)-Kautschuk, Polyorganosiloxan und Mischungen derselben;
• (C) 0 bis 30 Gew.-Teile an styrolhaltigem Copolymer, das hergestellt ist aus
• (C-1) 50 bis 95 Gew.-% Styrol, α-Methylstyrol, kernsubstituiertes Styrol, Methylmethacrylat oder einer Mischung davon und
• (C-2) 50 bis 5 Gew.-% Acrylnitril, C₁-C₈-Alkylmethacrylat, C₁-C₈-Alkylacrylat oder einer Mischung davon;
• (D) 5 bis 20 Gew.-Teile, bezogen auf 100 Gew.-Teile von (A) + (B) + (C), einer Mischung, umfassend
• (D-1) 100 bis 5 Gew.-Teile einer Mischung alkylsubstituierter Monophosphatester gemäß Formel (I)
  
  wobei R eine Alkylgruppe ist, ausgewählt aus t-Butyl-, Isopropyl-, Isobutyl-, Isoamyl-, t-Amyl-Gruppen und N 0 oder eine ganze Zahl von 1 bis 3 ist und
• (D-2) 0 bis 95 Gew.-% eines Phosphatesters der Formel (II)
  
  wobei R₁, R₂, R₄ und R₅ unabhängig voneinander Cresyl-, Phenyl-, Xylenyl-, Propylphenyl-, Butylphenyl- oder bromierte oder chlorierte Derivate derselben sind, R₃ eine Arylengruppe und M 0 bis 5 ist; und
• (E) 0 bis 2 Gew.-Teile, bezogen auf 100 Gew.-Teile von (A) + (B) + (C), eines fluorierten Polyolefinpolymers ist.

The invention relates to a thermoplastic resin composition comprising:

• (A) 40 to 95 parts by weight of a halogen-free thermoplastic polycarbonate;
• (B) 5 to 50 parts by weight of a styrene-containing graft copolymer prepared by grafting (B-1) onto (B-2), wherein
• (B-1) 5 to 95% by weight, based on (B), of a mixture of
• (B-1.1) 50 to 100% by weight of styrene, α-methylstyrene, nucleus-substituted styrene, methyl methacrylate or a mixture thereof, and
• (B-1.2) 50 to 0 wt .-% acrylonitrile, methacrylonitrile, C ₁ -C ₈ alkyl methacrylate, C ₁ -C ₈ alkyl acrylate, maleic anhydride, N-substituted maleimide or a mixture thereof, and
• (B-2) 95 to 5% by weight, based on (B), of a rubber having a glass transition temperature (Tg) of less than -10 ° C and selected from the group consisting of butadiene rubbers, acrylic rubbers, ethylene / propylene Rubbers, styrene / butadiene rubbers, acrylonitrile / butadiene rubbers, butadiene / styrene rubbers, polyisoprene, EPDM (ethylene-propylene-diene terpolymer) rubber, polyorganosiloxane and mixtures thereof;
• (C) 0 to 30 parts by weight of styrene-containing copolymer prepared from
• (C-1) 50 to 95% by weight of styrene, α-methylstyrene, nucleus-substituted styrene, methyl methacrylate or a mixture thereof and
• (C-2) 50 to 5% by weight of acrylonitrile, C ₁ -C ₈ -alkyl methacrylate, C ₁ -C ₈ -alkyl acrylate or a mixture thereof;
• (D) 5 to 20 parts by weight, based on 100 parts by weight of (A) + (B) + (C), of a mixture comprising
• (D-1) 100 to 5 parts by weight of a mixture of alkyl-substituted monophosphate esters of the formula (I)
  
  wherein R is an alkyl group selected from t-butyl, isopropyl, isobutyl, isoamyl, t-amyl groups and N is 0 or an integer of 1 to 3 and
• (D-2) 0 to 95% by weight of a phosphate ester of the formula (II)
  
  wherein R ₁ , R ₂ , R ₄ and R _{5 are} independently cresyl, phenyl, xylenyl, propylphenyl, butylphenyl or brominated or chlorinated derivatives thereof, R _{3 is} an arylene group and M is 0 to 5; and
• (E) 0 to 2 parts by weight, based on 100 parts by weight of (A) + (B) + (C), of a fluorinated polyolefin polymer.

In addition to the aforementioned Ingredients can the thermoplastic invention Resin compositions contain one or more conventional additives. For example, you can inorganic fillers such as mica, talc, zeolite and montmorillonite, pigments, dyes, Glass fibers, carbon fibers, thermal stabilizers, light stabilizers, Antioxidants, plasticizers and mold release agents in manufacturing processes as required be added.

Detailed Description of the Preferred Embodiments

The thermoplastic according to the invention Resin compositions include a polycarbonate, a styrene-containing Graft copolymer, optionally a styrene-containing copolymer, a Mixture of alkyl-substituted monophosphate esters, optionally one Phosphate ester compound and optionally a fluorinated polyolefin polymer.

following a detailed description of the relevant components is provided.

(A) Thermoplastic, halogen-free polycarbonates

wobei A eine Einfachbindung, C₁-C₅-Alkylen-, C₂-C₅-Alkyliden-, C₅-C₆-Cycloalkyliden-, -S- oder SO₂- ist.Suitable constituents (A) according to the invention are such thermoplastic halogen-free polycarbonates as are generally prepared by the reaction of diphenols of the following formula (III) with a phosgene or a carbonic acid diester.

wherein A is a single bond, C ₁ -C ₅ alkylene, C ₂ -C ₅ alkylidene, C ₅ -C ₆ cycloalkylidene, -S- or SO ₂ -.

suitable Diphenols of the formula (III) are, for example, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane and similar. The strongest preferred and widely used thermoplastic, halogen-free Polycarbonates are aromatic polycarbonates which from 2,2-bis (4-hydroxyphenyl) propane, called "bisphenol A" synthesized.

The preparation of the polycarbonates of component (A) suitable for use in the invention is known from the literature, for example U.S. Patent 3,169,121 It can be carried out in a known manner from diphenols with phosgene by means of the phase interface method or by means of phosgene using the homogeneous phase method.

preferred polycarbonates according to the invention show molecular weights (weight average) (Mw such as by ultracentrifugation or by light scattering measurements determined) from 10,000 to 500,000, preferably from 18,000 to 300,000. Polycarbonates with a certain molecular weight can be Use of a monophenol such as phenol, paracresol or paraisooctylphenol or a chain stopper. For the use according to the invention include suitable polycarbonates both homopolycarbonates and copolycarbonates.

at According to the invention, the polycarbonate resins (A) comprise a base resin in common with a styrene-containing graft copolymer and styrene-containing copolymers.

(B) Styrene-containing graft copolymers

• (B-1) 5 bis 95 Gew.-%, bezogen auf (B), einer Mischung von
• (B-1.1) 50 bis 100 Gew.-% Styrol, α-Methylstyrol, kernsubstituiertes Styrol, Methylmethacrylat oder eine Mischung derselben und
• (B-1.2) 50 bis 0 Gew.-% Acrylnitril, Methacrylnitril, C₁-C₈-Alkylmethacrylat, C₁-C₈-Alkylacrylat, Maleinsäureanhydrid, N-substituiertes Maleinimid oder eine Mischung davon,
• (B.2) 95 bis 5 Gew.-% bezogen auf (B), eines Kautschuks mit einer Glasübergangstemperatur (Tg) von unter –10°C und ausgewählt aus der Gruppe, bestehend aus Butadienkautschuken, Acrylkautschuken, Ethylen/Propylen-Kautschuken, Styrol/Butadien-Kautschuken, Acrylnitril/Butadien-Kautschuken, Butadien/Styrol-Kautschuken, Polyisoprenen, EPDM-Kautschuken, Polyorganosiloxanen und Mischungen derselben. Besonders bevorzugt ist als styrolhaltiges Pfropfcopolymer (B) das sogenannte ABS-Harz. Unter kernsubstituierten Styrolen sollen kern-alkylierte Styrole verstenden werden, wie z. B. p-Methylstyrol.

The styrene-containing graft copolymers used according to the invention are those which are prepared by grafting components (B-1) onto (B-2):

• (B-1) 5 to 95% by weight, based on (B), of a mixture of
• (B-1.1) 50 to 100 wt .-% of styrene, α-methyl styrene, nuclear substituted styrene, methyl methacrylate or a mixture thereof and
• (B-1.2) 50 to 0 wt .-% acrylonitrile, methacrylonitrile, C ₁ -C ₈ alkyl methacrylate, C ₁ -C ₈ alkyl acrylate, maleic anhydride, N-substituted maleimide or a mixture thereof,
• (B.2) 95 to 5% by weight, based on (B), of a rubber having a glass transition temperature (Tg) of below -10 ° C and selected from the group consisting of butadiene rubbers, acrylic rubbers, ethylene / propylene rubbers, Styrene / butadiene rubbers, acrylonitrile / butadiene rubbers, butadiene / styrene rubbers, polyisoprenes, EPDM rubbers, polyorganosiloxanes and blends thereof. Particularly preferred as the styrene-containing graft copolymer (B) is the so-called ABS resin. Core-substituted styrenes are understood to mean nuclear-alkylated styrenes, such as styrenes. For example, p-methylstyrene.

The preferred average particle size of the rubber is 0.05 up to 4 μm, about the impact resistance and to improve the appearance of the moldings.

The styrene-containing graft copolymers of component (B) can by means of conventional Process for the preparation of copolymers are produced, in particular Emulsion, suspension, solution or bulk polymerization. Preferred process for the preparation of the graft copolymer (B) is the emulsion or bulk polymerization process.

(C) styrene-containing copolymers

The styrene-containing copolymers of component (C) used in the present invention are those prepared from: (1) 50 to 95% by weight of styrene, α-methylstyrene, nucleus-substituted styrene, methyl methacrylate or a mixture thereof (C-1 ), and (2) 50 to 5% by weight of acrylonitrile, C ₁ -C ₈ -alkyl methacrylate, C ₁ -C ₈ -alkyl acrylate or a mixture thereof (C-2).

at a specific example of a styrene-containing copolymer it is SAN (styrene / acrylonitrile) resin, which is made by copolymerization of styrene and acrylonitrile is obtained. In the copolymerization 60 to 90 wt .-% styrene and 40 to 10 wt .-% acrylonitrile used.

The styrene-containing copolymer of component (C) can by means of conventional Copolymerization be prepared, in particular by means of Suspension or block polymerization.

(D-1) Mixture of Alkyl-Substituted Monophosphate Esters

wobei R eine Alkylgruppe ausgewählt aus t-Butyl-, Isopropyl-, Isobutyl-, Isoamyl-, t-Amyl ist und N 0 oder eine ganze Zahl von 1 bis 3 ist.The thermoplastic resin compositions of the present invention contain as a flame retardant a mixture of alkyl-substituted monophosphate esters (D-1) and a phosphate ester compound (D-2). Component (D-1) is a mixture of alkyl-substituted monophosphate esters of the following formula (I)

wherein R is an alkyl group selected from t-butyl, isopropyl, isobutyl, isoamyl, t-amyl and N is 0 or an integer from 1 to 3.

Preferably Component (D-1) is a mixture of alkyl-substituted ones Monophosphate esters containing from 1 to 20% by weight of trialkylphenyl phosphate (N = 3), 10 to 50% by weight of dialkylphenylmonophenyl phosphate (N = 2), 15 to 60% by weight of monoalkylphenyldiphenyl phosphate (N = 1) and less as 2% triphenyl phosphate (N = 0). In the preferred Substituents R are t-butyl and isopropyl radicals. The strongest preferred substituent R is t-butyl. A mixture of the t-butylphenyl phosphate ester mixture and the isopropylphenyl phosphate ester mixture is also preferred.

(D-2) phosphate ester

wobei R₁, R₂, R₄ und R₅ unabhängig voneinander eine halogenfreie Phenylgruppe oder C₁-C₄-alkylierte Arylgruppen sind,
R₃ eine Arylengruppe ist und
M 0 bis 5 ist.The phosphate esters of the invention have the following formula (II).

wherein R ₁ , R ₂ , R ₄ and R _{5 are} independently a halogen-free phenyl group or C ₁ -C ₄ -alkylated aryl groups,
R _{3 is} an arylene group and
M is 0 to 5.

at of the formula, the compound with M equal to 0 is a common one monomeric phosphate ester and the compound in which M is greater than 0 is an oligomeric phosphate compound. This means that the flame retardant Phosphate-based agent used in the thermoplastic Resin compositions according to the invention is usable, compounds according to formula (II) with values for M is from 0 to 5.

Preferred substituents R ₁ , R ₂ , R ₄ and R ₅ are independently one of cresyl, phenyl, xylenyl, propylphenyl, butylphenyl and their brominated or chlorinated derivatives. R ₃ is derived from diphenols, for example selected from bisphenol A, resorcinol or hydroquinone. Examples of preferred phosphate esters are phosphate esters such as triphenyl phosphate, tri (2,6-dimethylphenyl) phosphate, tri (4-methylphenyl) phosphate, tricresyl phosphate, diphenylcresyl phosphate, tri (isopropylphenyl) phosphate, trixylenyl phosphate, xylenyldiphenyl phosphate, an oligomeric phosphorus compound thereof, or mixtures of these compounds.

The thermoplastic according to the invention Resin compositions contain a mixture of (D-1) and (D-2) as a flame retardant. The weight ratios of (D-1) and (D-2) can be varied within a wide range. Preferably, the weight ratio of (D-1) to (D-2) between 100: 0 and 5:95, more preferably between 80:20 and 5:95, the strongest preferably between 55:45 and 15:85.

(E) Fluorinated polyolefin

preferred fluorinated polyolefins (E) are polytetrafluoroethylene, polyvinylidene fluoride, Tetrafluoroethylene / vinylidene fluoride copolymer and tetrafluoroethylene / hexafluoropropylene copolymer. These fluorinated polyolefins can alone or in mixtures with two or more other fluorinated ones Polyolefins are used. These polymers can be prepared by known methods be prepared, for example by means of polymerization of Tetrafluoroethylene in an aqueous medium with a free-radical-forming catalyst.

The Use of the fluorinated polyolefins sets the flow viscosity of the thermoplastic Resin composition and increases the shrinkage coefficient the composition in that during the Extruding a fibrillar Network is formed, whereby the drop of the melting resin decreases or prevented.

The fluorinated polyolefins can be used in the form of powder or emulsion. Fluorinated polyolefins in the form of an emulsion show good dispersibility, they do however, complicates the manufacturing process. That is why it is desired To use fluorinated polyolefins in powder form, which is uniform in total resin be dispersed and can form a fibrillar network.

at the fluorinated polyolefin used for the inventive use is suitable, it is polytetrafluoroethylene. polytetrafluoroethylene with an average particle size of 0.05 to 1000 microns is to Mixing suitable.

0 to 2.0 parts by weight of a fluorinated polyolefin polymer to 100 parts by weight of the base resin (A) + (B) + (C) are mixed.

Usual additives

In addition to the aforementioned Ingredients can the thermoplastic invention Resin Compositions One or more other conventional additives contain. For example, inorganic fillers, thermal stabilizers, Antioxidants, light stabilizers, plasticizers, pigments, dyes as well as mold release agents added become. The content of these conventional additives can be from 0 to 50 parts by weight, based on 100 parts by weight of the base resin (A) + (B) + (C).

The thermoplastic resin compositions are by means of conventional Production techniques for the production of resin compositions prepared, for example, by mixing the ingredients including the various additives and melt spinning with extruders in pellet form.

Description of the preferred embodiments

The illustrate the following examples - best practice included - the Procedures to carry out the invention. They are not listed to the scope of the invention as defined in the appended claims is, in what way to restrict. For all percentages this is% by weight, unless stated otherwise.

The The following ingredients were used in the following examples:

(A) polycarbonate

polycarbonate Bisphenol A type with a molecular weight (weight average) of 20,000 was used.

(B) Styrene-containing graft copolymer (ABS)

45 Parts by weight of a butadiene powder latex, 36 parts by weight of styrene, 14 Parts by weight of acrylonitrile and 150 parts by weight of deionized water were mixed, 1.0 parts by weight of potassium oleate, 0.4 parts by weight of cumene hydroperoxide and 0.3 parts by weight of a mercaptan based chain transfer agent were the mixed solution added. The resulting solution was at 75 ° C for 5 hours held to produce a graft ABS (g-ABS) latex. To the obtained Graft copolymer was added 1% sulfuric acid solution to ABS resin in powder form.

(C) Styrene-containing copolymer (SAN)

a mixed solution of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile and 120 parts by weight Deionized water was 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight tricalcium phosphate added. By suspension polymerization, Washing, dehydration and drying of the resulting product was a SAN copolymer produced. A SAN copolymer in powder form was receive.

(D-1) Mixture of t-butyl substituted Monophosphate esters

A Mixture of t-butyl-substituted monophosphate esters with 0.5% by weight Triphenyl phosphate, 33.2% by weight of diphenyl (t-butylphenyl) phosphate, 49.5 wt .-% phenyl-di (t-butylphenyl) phosphate and 12.5 wt .-% of tri (t-butylphenyl) phosphate was used.

(D-21) phosphate ester monomer

triphenyl (TPP) from Daihachi Co. of Japan was used.

(D-22) phosphate ester oligomer

resorcinol (RDP) with an average M value of 1.3 according to formula (II) was used.

(E) Fluorinated polyolefin

polytetrafluoroethylene with an average particle size of 10 to 50 μm was used.

Examples 1-4 and Comparative Examples 1-4

eight various thermoplastic resin compositions were known from mentioned above Ingredients in the in Table 1 below Quantity produced; the properties of these compositions are also shown in Table 1. The displayed components were mixed with an antioxidant and a Thermostabilisa tor and compounded in a twin-screw extruder (L / D 29, ø = 45). The extrudates obtained were pelletized, test pieces of which were pellets at a temperature of 220 ° C up to 280 ° C injection molded and then at 23 ° C, 50% RH held before measuring the properties.

The thermoplastic resin compositions of Examples 1 to 4 were those containing a mixture of t-butyl substituted monophosphate esters (D-1) and a phosphate ester monomer (D-21) or a phosphate ester oligomer (D-22). The thermoplastic resin compositions of Comparative Examples 1-4 were those having the same compositions as the composition of Example 1, but containing as the flame retardant only a monophosphate ester compound, an oligomeric phosphate ester compound, and both. Table 1 Examples Comparative Examples Example no. 1 2 3 4 1 2 3 4 Compositions (parts by weight) (A) polycarbonated 80 80 80 80 80 80 80 80 (B) Graft copolymer (g-ABS) 10 10 10 10 10 10 10 10 (C) SAN 10 10 10 10 10 10 10 10 (D-1) Mixture of t-butyl substituted monophosphates 7 3 7 3 - - - - (D-21) TPP 3 7 - - 10 - 7 3 (D-22) RDP - - 3 7 - 10 3 7 (E) fluorinated polyolefin (7AJ) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 properties Heat resistance (VST, ° C) ⁽¹⁾ 100 97 103 102 93 99 96 97 Crack number ⁽²⁾ 3 7 2 6 31 24 19 13 Total length of cracks (mm) ⁽³⁾ 13.5 35.4 11.3 33.7 235.5 194.7 150.5 89.3

INVESTIGATIONS

• (1) The heat resistance was according to ASTM D306 certainly.
• (2) Determined by measuring the number of cracks after storage in an oven at a temperature of 80 ° C for 24 hours after injection molding test pieces by means of a box-shaped Form was formed.
• (3) Determined by measuring the total length of cracks after storage in an oven at a temperature of 80 ° C for 24 hours after injection molding test pieces by means of a box-shaped Form was formed.

Examples 5 - 11 and Comparative Examples 5 - 8

Thermoplastic resin compositions having a composition shown in Table 2 and Table 3 were prepared by the same procedures as Examples 1 to 4, and the measured properties are also shown in Table 2 and Table 3. Table 2 Examples Example no. 5 6 7 8th 9 10 11 Compositions (parts by weight) (A) polycarbonate 80 80 80 80 80 80 80 (B) Graft copolymer (g-ABS) 10 10 10 10 10 10 10 (C) SAN 10 10 10 10 10 10 10 (D-1) Mixture of t-butyl substituted monophosphates 10 8th 8th 6 6 4 4 (D-21) TPP - 2 - 4 - 6 - (D-22) RDP - - 2 - 4 - 6 (E) fluorinated polyolefin (7AJ) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 properties Heat resistance (VST, ° C) 105 103 104 101 103 98 102 Number of cracks 1 3 2 6 5 11 7 Total length of cracks 5.3 13.5 11.3 33.7 29.6 53.1 36.7 Table 3 Comparative Examples Example no. 5 6 7 8th Compositions (parts by weight) (A) polycarbonate 80 80 80 80 (B) Graft copolymer (g-ABS) 10 10 10 10 (C) SAN 10 10 10 10 (D-1) Mixture of t-butyl substituted monophosphate esters - - - - (D-21) TPP 8th 2 6 4 (D-22) RDP 2 8th 4 6 (E) fluorinated polyolefin (7AJ) 0.4 0.4 0.4 0.4 properties Heat resistance (VST, ° C) 95 99 97 96 Rißzahl 28 18 25 23 Total length of cracks 124.3 103.2 117.6 110.8

As shown in Tables 1 and 2, Examples 1 to 4 and 5 to 11 a reinforced heat resistance as well as a drastic reduction in the number and length of the Cracks. In contrast, Comparative Examples 1 to 4 and 5 to 8 have poor heat resistance and an increased Number and length the cracks. As can be seen from the result of Tables 1, 2 and 3 can, showed the thermoplastic according to the invention Resin compositions containing as flame retardant a mixture alkyl-substituted monophosphate ester and a monomeric phosphate ester or an oligomeric phosphate ester, a decided higher Belastungsrißbeständigkeit as well as improved heat resistance towards those the comparative example with only the monomeric phosphate ester (Comparative Example 1), only the oligomeric phosphate ester (Comparative Example 2) or a mixture of monomeric and oligomeric phosphate ester (Comparative Examples 3 to 8).

Consequently, show the results that the Belastungsrißbeständigkeit and the heat resistance the thermoplastic invention Resin compositions substantially by a combination of flame retardant Means comprising a mixture of alkyl-substituted monophosphate esters and containing a phosphate ester compound is improved.

Claims (13)

A thermoplastic resin composition comprising (A) 40 to 95 parts by weight of a halogen-free thermoplastic polycarbonate; (B) 5 to 50 parts by weight of a styrene-containing graft copolymer prepared by grafting (B-1) to (B-2) (B-1) 5 to 95% by weight, based on (B), of styrene , α-methylstyrene, nucleus-substituted styrene, methyl methacrylate or a mixture thereof (B-2) 95 to 5% by weight, based on (B), of a rubber having a glass transition temperature (Tg) below -10 ° C and selected from A group consisting of butadiene, acrylic, ethylene / propylene, styrene / butadiene, acrylonitrile / butadiene, butadiene / styrene rubbers, polyisoprene, EPDM rubber, polyorganosiloxane and mixtures thereof; (D) 5 to 20 parts by weight, based on 100 parts by weight of (A) + (B), comprising (D-1) a mixture of alkyl-substituted monophosphate esters of the formula (I)

wherein R is an alkyl group selected from t-butyl, isopropyl, isobutyl, isoamyl, t-amyl groups, and N is 0 or an integer of 1 to 3. Thermoplastic resin composition according to claim 1, wherein (B-1) is composed of (B-1.1) 50 to 100% by weight Styrene, α-methylstyrene, nuclear substituted styrene, methyl methacrylate or a mixture of it, as well (B-1.2) 50 to 0% by weight of acrylonitrile, methacrylonitrile, C1-C8 alkyl methacrylate, C1-C8 alkyl acrylate, alkyl acrylate, maleic anhydride, N-substituted maleimide or a mixture thereof. Thermoplastic resin composition according to claim 1 or 2, where further containing 0 to 30 parts by weight of (C), in which (C) is a styrene-containing copolymer prepared from (C-1) From 50 to 95% by weight of styrene, α-methylstyrene, nuclear substituted styrene, methyl methacrylate or a mixture thereof and (C-2) 50 to 5% by weight of acrylonitrile, C1-C8-alkyl methacrylate, C1-C8 alkyl acrylate or a mixture thereof. A thermoplastic resin composition according to any one of claims 1 to 3, wherein (D), based on 100 parts by weight of (A) + (B) + (C), between 100 to 5% by weight of (D-1) and (D -2) 0 to 95 wt .-% of a phosphate ester of the formula (II)

wherein R ₁ , R ₂ , R ₄ and R _{5 are} independently cresyl, phenyl, xylenyl, propylphenyl, butylphenyl groups or brominated or chlorinated derivatives thereof, R _{3 is} an arylene group and M is 0-5. Thermoplastic resin composition according to any one of claims 1 to 4, further comprising a fluorinated polyolefin polymer (E) in in an amount of 0 to 2 parts by weight, based on 100 parts by weight (A) + (B) + (C) is included. Thermoplastic resin composition according to any one of claims 1 to 5, wherein the component (D-1) is a mixture which is 1 to 20 wt .-% of the alkyl-substituted monophosphate ester with a Value for N from 3.10 to 50% by weight of the alkyl-substituted monophosphate ester with a value for N from 2.15 to 60% by weight of the alkyl-substituted monophosphate ester with a value for N of 1 and less than 2 weight percent triphenyl phosphate. Thermoplastic resin composition according to any one of claims 1 to 5, wherein the weight ratio from (D-1) to (D-2) is between 80:20 and 5:95. Thermoplastic resin composition according to a the claims 1 to 5, wherein the weight ratio from (D-1) to (D-2) is between 55:45 and 15:85. Thermoplastic resin composition according to a the claims 1 to 5, wherein the alkyl group (R) is t-butyl. Thermoplastic resin composition according to a the claims 1 to 5, wherein the alkyl group (R) is isopropyl. Thermoplastic resin composition according to a the claims 1 to 5, wherein the component (D-1) is a mixture of mixed t-butyl substituted Monophosphate ester and mixed isopropyl substituted monophosphate ester is. Thermoplastic resin composition according to A after one of the claims 1 to 6, wherein the resin composition further comprises at least one Additive includes, which consists of the group consisting of inorganic fillers, Glass fibers, carbon fibers, thermal stabilizers, antioxidants, light stabilizers, plasticizers, Mold release agents, pigments and dyes is selected. Thermoplastic resin composition according to claim 6, wherein the component (D-1) is a composition of mixed t-butyl substituted Monophosphate ester comprising 1 to 20% by weight of tri (t-butylphenyl) phosphate, 10 to 50% by weight of di (t-butylphenyl) phenyl phosphate, 15 to 60% by weight Diphenyl (t-butylphenyl) phosphate and less than 2 wt .-% triphenyl phosphate includes.