DE1941189B2 - FLAME RESISTANT MODIFIED POLYAMIDES - Google Patents

Description

The pure polyamides, such as polyhexamethylene adipamide or polycaprolactam, are relatively heavy flammable substances. This reaction to fire changes with the incorporation of inorganic ones Fillers or mineral fibers. *>

Of course, the flammability is increased by adding flammable polymers such as polyethylene, Polypropylene, polyethylene terephthalate or phenoxy resins increased very much, and the more so, the more the proportion of flammable polymers is higher.

Polyamides containing block graft polymers, as described in the German patents 1131 883, 11 22 696, 11 38 922, 11 50 525, 11 49 170, 11 65 264 as well as in the patent applications DT-AS 1176 842, 16 45 198 and 1900 179. are relatively easy flammable molding compounds that no longer extinguish themselves.

It is known. Self-extinguishing equip polymers having relatively low melting points below 200 ⁰ C, such as polyethylene, polystyrene, polymethacrylic esters, and polyurethanes, by the addition of halogen-containing substance in combination with antimony derivatives (French Patent 13 71 629, German Patent 11 23 823). In the case of polyamides, the addition of brominated hydrocarbons causes a deterioration in the appearance, the physical properties and often a deterioration in the reaction to fire, as is shown in various comparative examples. The cause is to be found in the relatively high melting temperatures of the polyamides and the decomposition of the brominated hydrocarbons that occurs in the process.

The much more stable chlorinated hydrocarbons improve the non-flammability of the polyamides not unless relatively large amounts of 20 to 40% are added, although the good physics see Properties of the polyamides are lost.

The same also applies to very stable, perbrominated aryl compounds. Compounds containing hydrogen bromide Substances that form hydrogen bromide in the polyamide melt are very destructive Effect on the polyamides, so that any improvements in flame retardancy are worthless.

It has surprisingly been found that filler-containing polyamide molding compounds or block graft polymers can be used containing polyamides can be made flame-retardant if you add 2 to 15 percent by weight, based on the total mixture of a strongly brominated phenyl ether and 2 to 15 percent by weight Antimony trioxide or an antimonyl compound very homogeneously into the melt of the polyamide molding compounds to be finished kneads. Care must be taken that the strongly brominated phenyl ether is free from any Amounts of hydrogen bromide. This kneading can be done in conventional disk kneaders and screw presses at temperatures of about 10 to 50 ° C above the Melting point of the polyamide molding compounds to be finished.

Polyamides containing block graft polymers are molding compounds made from polylactams such as polycaprotectam, Polycaprylic lactam or polylaurolactam or polycondensates from dicarboxylic acids and diamines, such as polyhexamethylene adipamide or polyhexamethylene sebacamide with polyolefins such as polyethylene, polypropylene or ethylene copolymers with vinyl acetate, Methacrylic esters, acrylic esters or acrylonitrile are to be understood, furthermore molding compositions made from the aforementioned Polyamides with saturated polyesters, such as polyethylene terephthalate or with polyacetals, in particular high molecular weight polyformaldehyde as well as with epoxy resins and phenoxy resins, made from Alkyl or arylalkylene oxides or haloalkyl alkylene oxides, in particular from epichlorohydrin and bisphenols such as 2,2- (4,4'-dioxide-diphenyl) propane or 4,4'-dihydroxy diphenyl ether.

Filler-containing polyamide molding compounds are homo-polyamides, Polyamides containing mixed polyamides and block graft polymers from the starting materials listed with 10 to 40 percent by weight of inorganic fillers such as precipitated silica, aluminum hydroxide, Clay gel, kaolin, chalk, glass and asbestos fibers.

Flame-retardant substances within the meaning of the invention are halogenated, in particular brominated phenyl ethers such as pentabromodiphenyl ether, octabromodiphenyl ether, 1,2-dibromopropyl tribromophenyl ether or pentabron-2,3-dibromopropyl ether in conjunction with half to double the amount by weight of antimony trioxide, antimony III) hydroxide, sodium antimonite (NaSbO. '); Antimonyl chloride (SbOCl); Antimonyl potassium tartrate (emetic tartar) or complex antimony oxalates such as NaSb (CzOi) ₂ .

In order to achieve a self-extinguishing effect, additives of 4 to 30 percent by weight of all are flame retardant Connections, based on the total amount required. Polyamide molding compounds require the smallest amount of additives with a relatively high content of carbonamide groups and a low proportion of inorganic fillers and hydrocarbon-containing copolymers or graft polymers. Particularly beneficial for the incorporation of the flame-retardant additives are solid, finely powdered substances such. B. the octabromo-diphenyl ether in conjunction with antimony trioxide. Liquid or waxy brominated phenyl ethers are more difficult to mix with the granulated polyamide molding compounds, and they are also difficult to mix dose.

According to the invention, the components, that is, the granulated polyamides or block graft polymers containing polyamides with the fillers, possibly with the alloy components and the flame-retardant additives mixed in a paddle mixer at room temperature, then fed to a heated extruder via a metering device.

In this device, it is advantageous to use twin-screw extruders with mutually meshing Screws, the thermoplastic components are melted, all components by one intensive kneading finely divided, any volatile components removed through a degassing nozzle and the Melt extruded in the form of strands or strips, quenched in water and then after removal of the

adhering moisture wound up or granulated. 5 parts

The components can of course also be 6 parts

are fed separately to the kneading device. This is particularly recommended for larger additions of 90 parts liquid components, which are expediently transferred via a metering pump synchronously to the melt in the extruder a hole in the housing can be metered.

According to the described, inventive 5 parts

driving you get flame retardant organic materials, 5 parts

especially in the electrical sector and wherever a Self-extinguishing or flame resistance is required, can be used. 92 pieces

The added flame retardants may be 3 parts

the high level of properties of the raw materials, the 5 parts

Color or the long-term behavior of those treated with it Polyamide molding compounds do not noticeably change, no FaJI in a negative way for 87 parts. 6 parts

The added flame retardants may exceed 7 parts

In addition, the tools do not sweat out or be easily extracted when deforming in injection molding machines attack or even irritate 80 parts of the human skin or the mucous membranes.

For the reasons mentioned, the known perchlorinated substances such as chlorinated paraffins or highly chlorinated alkyl or aryl esters of phosphoric or phosphorous acid.

Examples

The parts given in the examples are 8 parts

Parts by weight. 30 12 parts

example 1

A polyamide containing block graft polymer, consisting of 90 parts of polyhexamethylene adipamide and 10 parts of polyethylene, is kneaded with 8 parts of 84 parts of pentabromodiphenyl ether and 12 parts of antimony trioxide in a single-screw extruder. One extru- ⁷ parts

Serving, in water quenched 2.5 to 3.0 mm thick ⁹ parts

The strand does not burn if you hold it in a gas flame for 3 to 5 seconds. The one through prolonged exposure to flames Burning strand extinguishes by itself within 10 4 ° 85 parts seconds after removal from the flame.

Pentabromo diphenyl ether +
Antimony trioxide

of a 6-polyamide containing block graft polymers according to German Patent 11 22 696 with a gross composition of 90 parts of PA 6 and 10 parts of PE +
Octabromodiphenylether +
Antimony trioxide or 5 parts of antimony (III) hydroxide

Polycaprolactam with 25% glass fiber +

Pentabromo-phenyl-tribromo-ethylene-ether

Antimonyl chloride

Polycaprolactam with 35% glass fibers
Penlabromo-phenyl-tribromo-phenyl-ether
Antimony trioxide or 7 parts antimonyl chloride

of a polyamide containing block graft polymers according to German patent application P 16 94 472, consisting of 60 parts of polyhexamethylene adipamide, 10 parts of an ethylene copolymer with 7% butyl acrylate, 10 parts of a phenoxy resin of 2,2- (4,4 ' -Dioxide-diphenyl) -propane and epichlorohydrin and 20 parts of kaolin (A 4)
Pentabromo diphenyl ether
Antimonyl potassium tartrate or 12 parts of antimony trioxide or 12 parts of sodium dioxalatoantimonite

of the modified PA 66 A 4 + described above

Octabromodiphenylether +
Antimonyl potassium tartrate or 9 parts sodium dioxalato antimonite

Example 2

Α parts of those listed in the following table Block graft polymers containing polyamides or filler-containing polyamides, which after flaming continued to burn by themselves, various brominated phenyl ethers were made with B parts and various brominated phenyl ethers with C parts of various antimony compounds equipped to be self-extinguishing by adding the additives as in Example 1 described, incorporated into the polyamides via the melt in an extruder. The exam was done according to the standard method of ASTM-D 635 - 56 T. A test rod with the dimensions of 0.05 inches = 1.27 mm χ 0.5 in. = 1.7 cm χ 5 in. = 12.7 cm comes with an approximately 2.5 cm high discolored gas flame of a Bunsen burner flamed for 30 seconds. The test material was as Designated flame-retardant if, after removing the test rod, the flame is within 20 Seconds went off by itself and after a double exposure to flame within 30 seconds.

Recipes for flame retardant polyamides

89 parts of a polycaprolactam containing block graft polymer with the product composition 90% PA 6 and 10% polyethylene +

of the PA66 setting A4 containing block graft polymers with 7.5 parts of pentabromo-phenyl-2,3-dibromopropyl ether +
Parts of antimony (III) hydroxide or 5 parts of sodium antimonite

Parts of a 6-polyamide containing block graft polymers according to German patent application P 19 00 179, consisting of 90 parts of polycaprolactam and 10 parts of polyethylene terephthalate (A 5) +
Share octabromo-diphenyl ether +

Parts of antimony trioxide or 6 parts of antimony trihydroxide or 4 parts of antimonyl chloride + 2 parts of sodium antomonite

Parts of the Blockpfrop ^r polymers containing PA 6 (A 5) +

Parts of tribromophenyl-2,3-dibromopropyl ether +

Parts of antimony trioxide or 4 parts of antimony trioxide and 4 parts of antimonyl chloride

Parts of a block graft polymer containing! 2-polyamides (A 6) (poly-laurin-lactam) according to German patent 11 50 525 from 10 parts of high molecular weight polyformaldehyde and 90 parts of polylaurolactam, mixed with 15 parts of glass fibers +

10 parts of pentabromo-phenyl-tribromo-ethyl-ether +
IO parts of antimony trioxide or 10 parts of antimony trihydroxide

75 parts of the previously described fiberglass-filled

12-PA / POM setting (A 6)
8 parts of petabromo-phenyl ^ -dibromopropylether +
Yl parts of antimony trihydroxide

90 parts of a glass fiber reinforced 6/10 polyamide containing block graft polymers with the Composition 75 parts of polyhexa-methylene-sebacamide (6/10-PA) (A 7) and 5 parts of polypropylene + 20 parts of glass fibers added one with

5 parts octabromo-diphenyl ether and
5 parts of antimony trioid

90 parts of the previously described compound A 7 were mixed with

5 parts of pentabromophenyl-2,3-dibromopropyl ether
and

2 parts antimonyl potassium tartrate and

3 parts of antimony trioxide

Comparative examples

88 parts of a 6-polyamide (polycaprolactam) containing block graft polymers 90 parts of PA 6 (polycaprolactam) + 10 parts of polyethylene (A 1) were mixed with

7 parts of tris (2,3-dibromopropyl) phosphate and

5 parts of antimony trioxide

This setting was self-extinguishing, but severely embrittled and post-extrusion discolored brownish.

The halogenated compounds mentioned in the following comparative examples did not cause any self-extinguishing effects Finishing of the polyamides containing block graft polymers.

1. Recipe

90 pieces

5 parts
5 parts

90 parts A 1 +

5 parts octabromo-diphenyl +

5 parts of antimony trioxide

90 parts A 1 +

5 parts of hexabromo-cyclo-dodecane +

5 parts of antimony trioxide

90 parts A 1 +

5 parts of 2,2- (3,3 ', 5,5'-tetrabromo-4,4'-dioxi-diphenyl) -

propane

5 parts of antimony trioxide

90 parts A 1 + 5 parts 3,3 \ 5,5'-tetrabromo-4,4'-dioMi-diphenyl-me-

than 5 parts of antimony trioxide

90 parts of A1 + 5 parts of tetrabromophthalic anhydride 5 parts of antimony trioxide (the addition of tetrabromophthalic anhydride causes the material to expand considerably).

90 parts A 1 + 5 parts hexachloro-endomethylene-tetrahydrophthalic acid (HET acid) 5Te; '' Antimony trioxide (this setting has been discolored intensely black).

20th

30th

35

40

of the PA-6 containing block graft polymers and having a gross composition of 90 parts of polycaprolactam and 10 parts of polyethylene (A 1) + pentabromodiphenyl +
Antimony trioxide

90 parts A 1 +

5 parts of ammonium chloride

5 parts of antimony trioxide

90 parts A 1 +

5 parts of ammonium bromide

5 parts of antimony trioxide

90 parts A 1 +

5 parts of tribromo-trichlorobenzene

5 parts of antimony trioxide

90 parts A 1 +

5 parts of bromophenol

5 parts of antimony trioxide

90 parts A 1 +

5 parts of dichloroethyl phosphite

5 parts of antimony trioxide

90 parts A 1 +

5 parts of trichloroethyl phosphate

5 parts of antimony trioxide

90 parts A 1 +

5 parts of tris-chlorocresyl phosphate

5 parts of antimony trioxide

90 parts A 1 +

5 parts of tris-bromocresyl phosphate

5 parts of antimony trioxide

90 parts A 1 +

5 parts chlorinated paraffin

5 parts of antimony trioxide

55 In the recipes listed for flame-retardant polyamide settings, replacing antimony trioxide with the same amount of borax worsened the fire behavior.

Claims (1)

Claim: Use of a mixture of 2 to 15 percent by weight, based on the total mixture, a highly brominated phenyl ether and 2 to 15 percent by weight of an antimony trioxide or antimonyl compound for the flame-retardant finishing of filler-containing polyamide molding compounds or of polyamines containing block graft polymers> o the.