DE19539443B4 - Flame retardant thermoplastic resin molding compounds - Google Patents

Abstract

Flame retardant thermoplastic resin compounds consisting of
A) 40 to 100 parts by weight of one or more halogen-free thermoplastic ter- or multipolymers
a) 10 to 90% by weight of styrene and / or a styrene derivative,
b) 5 to 50% by weight of at least one monomer selected from acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride, N-phenylmaleimide,
c) 5 to 40% by weight of hydroxyethyl methacrylate and / or hydroxypropyl methacrylate,
B) 10 to 60 parts by weight of ammonium polyphosphate,
C) 0 to 40 parts by weight of at least one further polymer component and
D) 0 to 20 parts by weight of at least one nitrogenous compound.

Description

Flame retardant plastics are becoming increasingly popular used, e.g. For casing of electrical and electronic equipment, Parts for Electrical installations (sockets, switch housings) and parts for electrical heating.

Because when using halogen Additives corrosive combustion gases are formed in the event of fire there is a need for flame-retardant halogen-free Plastics.

The present invention relates to thermoplastic, flame-retardant halogen-free resin molding compounds based on styrene copolymers with high hardness or high modulus of elasticity.

Thermoplastic molding compositions based on styrene copolymers with halogen-free flame retardant equipment are known and, for example, in DE-OS 3 920 995 and the literature cited there.

The molding compositions generally contain as a means of achieving flame retardant additives from the group of low molecular weight nitrogen-containing or phosphorus-containing compounds in relative terms high proportions. Since such connections are usually a If they do not have a plasticizing effect, they are halogen-free flame retardant Molding compounds with high hardness or high modulus of elasticity.

Object of the present invention is to such resin molding compounds based on polymeric components without losses with hardness or modulus of elasticity while largely maintaining the other properties provide.

Under flame-retardant resin molding compounds are products to be understood that according to the underwriter Laboratories UL-94 fire test classification classifications V0 and achieve V1.

• A) 40 bis 100 Gew.-Teilen, bevorzugt 45 bis 95 Gew.-Teilen und besonders bevorzugt 50 bis 90 Gew.-Teilen eines oder mehrerer halogenfreier thermoplastischer Ter- oder Multipolymerisate aus a) 10 bis 90 Gew.-%, vorzugsweise 20 bis 80 Gew.-% Styrol und/oder einem Styrolderivat, b) 5 bis 50 Gew.-%, vorzugsweise 10 bis 40 Gew.-%, mindestens eines Monomeren ausgewählt aus Acrylnitril, Methacrylnitril, Methylmethacrylat, Maleinsäureanhydrid, N-Phenylmaleinimid, c) 5 bis 40 Gew.-%, vorzugsweise 10 bis 35 Gew.-%, Hydroxyethylmethacrylat und/oder Hydroxypropylmethacrylat,
• B) 10 bis 60 Gew.-Teilen, bevorzugt 15 bis 50 Gew.-Teilen und besonders bevorzugt 20 bis 40 Gew.-Teilen Ammoniumpolyphosphat,
• C) 0 bis 40 Gew.-Teilen, bevorzugt 0 bis 30 Gew.-Teilen und besonders bevorzugt bis 25 Gew.-Teilen mindestens einer weiteren Polymerkomponente und
• D) 0 bis 20 Gew.-Teilen, bevorzugt 0 bis 15 Gew.-Teilen und besonders bevorzugt 0 bis 12,5 Gew.-Teilen mindestens einer stickstoffhaltigen Verbindung.

Molding compositions according to the invention which meet the requirements described above consist of

• A) 40 to 100 parts by weight, preferably 45 to 95 parts by weight and particularly preferably 50 to 90 parts by weight of one or more halogen-free thermoplastic ter- or multipolymers of a) 10 to 90% by weight, preferably 20 up to 80% by weight of styrene and / or a styrene derivative, b) 5 to 50% by weight, preferably 10 to 40% by weight, of at least one monomer selected from acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride, N-phenylmaleimide, c ) 5 to 40% by weight, preferably 10 to 35% by weight, hydroxyethyl methacrylate and / or hydroxypropyl methacrylate,
• B) 10 to 60 parts by weight, preferably 15 to 50 parts by weight and particularly preferably 20 to 40 parts by weight of ammonium polyphosphate,
• C) 0 to 40 parts by weight, preferably 0 to 30 parts by weight and particularly preferably up to 25 parts by weight of at least one further polymer component and
• D) 0 to 20 parts by weight, preferably 0 to 15 parts by weight and particularly preferably 0 to 12.5 parts by weight of at least one nitrogen-containing compound.

Halogen free thermoplastic resins A) are those that consist of monomer combinations of at least one Styrene derivative, at least one other monomer selected from Acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride or N-phenylmaleimide and at least one containing hydroxyl groups Monomers selected made up of hydroxyethyl methacrylate and hydroxypropyl methacrylate are.

Preferred styrene derivatives are unsubstituted styrene, nucleus-substituted styrenes (such as p-methylstyrene) and α-methylstyrene used. additionally can the thermoplastic resin component A) other halogen-free monomers included in a small amount (maximum 15% by weight).

Examples of such monomers are vinyl acetate and esters of acrylic acid or methacrylic acid with 1 to 8 carbon atoms in the alcohol component (e.g. butyl acrylate, 2-ethylhexyl acrylate).

Examples of thermoplastic resins A) are Styrene / acrylonitrile / hydroxyethyl methacrylate polymers, styrene / methyl methacrylate / hydroxyethyl methacrylate polymers, α-methylstyrene / acrylonitrile / hydroxyethyl methacrylate polymers, Styrene / acrylonitrile / hydroxy propyl methacrylate polymers.

The preparation of the polymers can according to all common Polymerization processes (e.g. solution polymerization, Bulk polymerization, emulsion polymerization, suspension polymerization) respectively; can do this if necessary molecular weight regulators (e.g. mercaptans, dimeric α-methylstyrene) be used.

The molecular weights of the polymerization A) can be varied within wide limits; products with weight average molecular weights ( M _w ) from about 40,000 to 150,000, particularly preferably from about 50,000 to 120,000.

Component B) is used in the molding compositions according to the invention Ammonium polyphosphate used. Ammonium polyphosphate is preferred with one enough high molecular weight used (> 4,000), so that one preferably low water solubility is ensured.

The resin molding compositions according to the invention can also be used additional contain halogen-free polymer components (component C).

Examples of such polymer components are graft rubbers of the ABS type (produced by copolymerization of styrene / acrylonitrile mixtures in the presence of polybutadiene) and of the MBS type (produced by copolymerization of methyl methacrylate / styrene mixtures in the presence of polybutadiene), of the AES type (produced by copolymerization of styrene / acrylonitrile mixtures in the presence of EPDM rubber), of the ASA type (produced by copolymerization of styrene / acrylonitrile mixtures) in the presence of acrylate rubber); Rubbers such as ethylene / vinyl acetate copolymers or nitrile rubbers (copolymers of butadiene and acrylonitrile, in particular those products which are additionally modified by built-in acid groups); Resin components such as, for example, vinyl polymer resins (for example styrene / acrylonitrile copolymers, polymethyl methacrylate, α-methylstyrene / acrylonitrile copolymers, methyl methacrylate / acrylonitrile copolymers, methyl methacrylate / styrene copolymers) or polycondensates (for example bisphenol A polycarbonates, polyethylene terephthalates), polybutyl amides, polybutyl amides, polybutylene amides

In addition, the resin molding compositions according to the invention contain nitrogenous compounds (component D). Examples for such Compounds are triazine derivatives such as Melamine, melamine salts, cyanurates.

The mixtures according to the invention containing components A), B), optionally C) and D) and optionally the usual Additives such as lubricants, stabilizers, pigments, mold release agents, Antistatic agents, fillers such as. Glass fibers are made by using the ingredients in a known manner simultaneously or successively at room temperature or at higher Temperature mixed and then at 150 ° C to 300 ° C in common units such as internal kneaders, Extruders or twin-screw extruders melt-compounded or melt-extruded.

The molding compositions according to the invention can Manufacture of molded articles any type can be used, with usual processing methods, e.g. Injection molding or Extrusion, can be used.

Examples

Components used:

Thermoplastic Components A)

• A1: Polymer prepared by emulsion polymerization of a monomer mixture composed of 64 parts by weight of styrene, 21 parts by weight of acrylonitrile and 15 parts by weight of hydroxyethyl methacrylate L value = 111 (L value = η _spec. / C at c = 5 g / l in DMF at 25 ° C)
• A2: polymer produced by emulsion polymerization of a Monomer mixture of 63.75 parts by weight of styrene, 21.25 parts by weight Methyl methacrylate and 15 parts by weight of hydroxyethyl methacrylate L value = 91
• A3: Polymer prepared by emulsion polymerization of a Monomer mixture of 53 parts by weight of styrene, 17 parts by weight of acrylonitrile and 30 parts by weight of hydroxyethyl methacrylate L value = 98
• A4: polymer produced by emulsion polymerization of a Monomer mixture of 52.5 parts by weight of styrene and 17.5 parts by weight Methyl methacrylate and 30 parts by weight of hydroxyethyl methacrylate L value = 88
• B1: Ammonium polyphosphate: Hostaflam ^® 423 (Hoechst AG)
• B2: Ammonium polyphosphate: Budit ^® 365 (Chemische Fabrik Budenheim)
• C1: Polymer produced by radical solution polymerization a monomer mixture of 72 parts by weight of styrene and 28 parts by weight acrylonitrile L value = 80
• D1: Melamine cyanurate (3V Sigma)
• E: triphenyl phosphate (Disflamoll ^® TP, Bayer AG)

The components were in the in Table 1 parts by weight mixed in a kneader. The exams took place at 200 to 220 ° C pressed Specimens.

The following values were determined:
Fire behavior according to UL regulations on vertically clamped 3.2 mm test bars,
Heat resistance according to Vicat B (DIN 53 460) in ° C,
Impact strength a _n according to DIN 53 453 in kJ / m ² ,
Shore D hardness (DIN 53 505).

The measured values are summarized in Table 2.

From this it can be seen that only the Molding compositions according to the invention a cheap one Combination of good flame resistance and high hardness without significant influence on the others Have properties.

Table 2: Data of the molding compounds tested

Claims (3)

flame-retardant thermoplastic resin molding compositions consisting of A) 40 to 100 Parts by weight of one or more halogen-free thermoplastic Ter- or multipolymerizates a) 10 to 90 wt .-% styrene and / or a styrene derivative, b) at least 5 to 50% by weight of a monomer selected from acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride, N-phenyl, c) 5 to 40 wt .-% hydroxyethyl methacrylate and / or hydroxypropyl methacrylate, B) 10 to 60 parts by weight ammonium polyphosphate, C) 0 to 40 parts by weight of at least one further polymer component and D) 0 to 20 parts by weight at least a nitrogenous compound. flame-retardant Thermoplastic resin molding compositions according to claim 1, consisting of A) 45 to 95 parts by weight of one or more halogen-free thermoplastic Ter- or multipolymerizates a) 20 to 80 wt .-% styrene and / or a styrene derivative, b) at least 10 to 40% by weight of a monomer selected from acrylonitrile, methacrylonitrile, methyl methacrylate, maleic anhydride, N-phenyl, c) 10 to 35 wt .-% hydroxyethyl methacrylate and / or hydroxypropyl methacrylate, B) 15 to 50 parts by weight ammonium polyphosphate, C) 0 to 30 parts by weight of at least one further polymer component and D) 0 to 15 parts by weight at least a nitrogenous compound. Use of the molding compositions according to claims 1 and 2 for the production of molded parts.