JPH0761659B2 - Flame-retardant polyamide moldings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a component in the electronic and electrical fields requiring high flame retardancy.

[Prior Art] Since high flame retardancy is required in the electronic and electrical fields, flame retarded resin is usually used. In particular, flame-retardant nylon 66 is praised for its good moldability and high heat resistance. One of the methods for making nylon 66 flame-retardant is to add a halogen-based flame retardant. Conventionally, a cyclooctadiene adduct of hexachlorocyclopentadiene has been used as a flame retardant, but there is a problem that it causes partial thermal decomposition during molding, leading to discoloration of the molded product and deterioration of mechanical properties. Recently, a polymer type brominated flame retardant has been developed and proposed as an improvement over these drawbacks. Particularly, nylon 66 includes brominated polystyrene (JP-A-51-47034, JP-A-51-47044, JP-A-53-9656) or brominated polyphenylene oxide (JP-B-56-6100). Gazette, Japanese Patent Publication No. 60-41093
No. gazette) is suitable. Of these two types, the former is more excellent than the latter in terms of discoloration due to heat deterioration during molding and deterioration of mechanical properties, and has been put to practical use in many cases.

[Problems to be Solved by the Invention] In recent years, electronic / electrical parts have been rapidly becoming lighter, thinner, shorter, and smaller with the technical progress thereof, and thin and small products which have never existed before have been developed and put into practical use. .

In such a movement, a polyamide composition using brominated polystyrene as a flame retardant is insufficient in mechanical strength of the thin wall portion, particularly when a molded product having a weld portion in a thin wall portion of 0.8 mm or less is injection-molded. It turns out that there is a problem of doing.

This has not been experienced with conventional, normal thick products.

[Means for Solving Problems] The inventors of the present invention have made earnest studies on this new problem, and as a result, found that a composition composed of brominated polyphenylene oxide and polyamide is a material that can address the problem. Heading out, the present invention was reached.

That is, the present invention is as follows.

0 to 1 to 100 parts by weight of a composition consisting of 50 to 95% by weight of polyamide, 5 to 35% by weight of optionally branched brominated polyphenylene oxide, and 0 to 15% by weight of metal oxide.
A molded product obtained by injection molding a flame-retardant polyamide resin composition containing 00 parts by weight of a reinforcing agent, having a thin-walled portion having a wall thickness of 0.8 mm or less, and a welded portion is present in the thin-walled portion. Flame-retardant polyamide molded product that does.

The polyamide referred to in the present invention is a polyamide containing an aliphatic linear polyamide as a main component. Polyamide obtained by condensation polymerization of aliphatic dicarboxylic acid and aliphatic diamine,
A polyamide obtained by condensation polymerization of an aliphatic aminocarboxylic acid, an aliphatic polyamide obtained by ring-opening polymerization of a lactam, a copolymer thereof, a polymer blend, or a weld strength of a thin portion in the present invention is not reduced. Polyamides other than the above in amounts within the range, such as aromatic dicarboxylic acids, aromatic diamines, alicyclic dicarboxylic acids, alicyclic diamines, etc., may be copolymerized or polymer blended. Specific examples include the following, but the invention is not limited thereto. For example nylon 66, nylon 46, nylon 610, nylon 612, nylon 6, nylon 1
1, Nylon 12, and copolymers or polymer blends thereof, or those in which hexaethylene terephthalamide, hexamethylene isophthalamide, cyclohexyl adipamide, etc. are copolymerized or polymer blended therein.
Among these nylons, particularly nylon 66, nylon 6 and copolymers or polymer blends thereof, the effect of the present invention tends to be remarkably exhibited. Nylon 66, nylon 46, copolymers containing these as the main components, and polymer blends have high heat resistance and are therefore important for solder resistance, especially for surface mount materials.

The amount of polyamide added is 50 to 95% by weight. If it is less than 50% by weight, the mechanical strength of the thin welded part is significantly reduced,
If it exceeds 95% by weight, flame retardancy is lacking.

The brominated polyphenylene oxide referred to in the present invention is a compound having a structure represented by the following general formula and functions as a flame retardant.

In the formula, m is an integer of 5 to 500, n is 0 or 1 or 2, l is an integer of 0 to 500, 5 ≦ m + l ≦ 500, Br is at the ortho or para position with respect to —O—, and Y Is It is a side chain having the following structural formula, and is attached at the position ortho to the main chain —O—. The end of the main chain (M is hydrogen or a monovalent metal), and the end of the side chain is Is.

The flame retardant can be produced by polymerizing tribromophenol. It may be produced by polymerizing a metal salt of tribromophenol.

The flame retardant contains at least 60% by weight bromine.
It is preferable to contain 62 to 66% by weight of bromine.

The amount of flame retardant added is 5 to 35% by weight, preferably 15 to
25% by weight. If it is less than 5% by weight, the flame-retardant effect is not sufficient, and if it exceeds 35% by weight, the mechanical strength of the thin weld portion is remarkably lowered.

In addition to the above flame retardant, it is effective to supplementally add a metal oxide having a flame retardant effect. By doing so, the amount of the flame retardant added can be reduced. Examples of the metal oxide that can be used include antimony compounds such as antimony trioxide and sodium antimonate, zinc oxide, iron oxide, tin oxide, calcium oxide, magnesium oxide, aluminum oxide, copper oxide and titanium oxide. Zinc borate is also known as an effective compound. The amount of the metal oxide added is 0 to 15% by weight, preferably about 3 to 9% by weight. Too much blending is not preferable because the mechanical strength of the entire composition decreases.

It is desirable to strengthen the compositions of the present invention with a reinforcing agent. This is because the rigidity of the non-reinforced polyamide is insufficient because the electronic and electric parts are thin. In addition, the reinforced material has less dimensional change due to water absorption and tends to have a higher heat distortion temperature. As the reinforcing agent, a well-known nylon reinforcing agent / filler can be used. Examples thereof include glass fibers, carbon fibers, fibrous reinforcing agents such as potassium titanate, and inorganic fillers such as wollastonite, kaolin, calcined kaolin, talc, mica, graphite and glass beads. Especially glass fiber reinforcement is preferable. The amount of these reinforcing agents added is
The amount is 0 to 100 parts by weight, preferably 5 to 45 parts by weight, and more preferably 15 to 30 parts by weight, based on 100 parts by weight of the composition comprising polyamide, brominated polyphenylene oxide and flame retardant aid.

If the amount of the reinforcing agent is too small, the effect will be insufficient, and if the amount of the reinforcing agent is too large, the fluidity at the time of molding will be deteriorated and the surface of the molded product will be roughened or short shots will occur.

The composition of the present invention may contain known additives to polyamide. Olefinic polymers as toughening agents or anti-drip agents, eg ethylene ionomers, acid modified
EP rubber, acid-modified styrene-based polymer and the like may be added as long as the effects of the present invention are not impaired. Copper compounds, halogen-metal salts, hindered phenols, sulfur-containing compounds, amine compounds, etc. as heat stabilizers; stearic acid metal salts, ethylenebisstearylamide, as lubricants
Montanic acid ester, metal salt of montanic acid, polyethylene glycol, colorant such as mineral oil, plasticizer, ultraviolet absorber,
An antistatic agent or the like can be added.

The method for producing the composition of the present invention can be carried out by a known method and is not particularly limited. For example, a general method is to triblend a polyamide, a flame retardant, a flame retardant aid, a reinforcing agent, and other additives, and melt-knead them using an extruder.
It is preferable to improve the dispersion of brominated polyphenylene oxide, which is a flame retardant, in terms of flame retardancy, mechanical properties, and the like. In particular, those having a dispersed particle diameter of 1 μm or less have good physical properties. For this purpose, it is effective to use a twin-screw extruder. A method in which a polyamide, a flame retardant, and in some cases, a flame retardant auxiliary agent are melt-kneaded in a twin-screw extruder and a reinforcing agent is side-fed brings a good physical property effect.

The molded article of the present invention has a thin portion having a thickness of 0.8 mm or less,
A molded product having a welded portion in the thin portion. The composition of the present invention is uniquely excellent in such molded articles. This effect is more remarkable in the molded product having a thin portion of 0.4 mm or less.

[Effects of the Invention] According to the present invention, a molded product that meets the needs for lighter, thinner, shorter, and smaller electronic and electric parts and has a thin weld portion with high strength can be manufactured by injection molding with high productivity.

[Examples] The effects of the present invention will be described below with reference to Examples.

Examples 1 to 3, Comparative Examples 1 to 6 Nylon 66 (Leona 1300S) as pellets and flame retardant
Brominated polyphenylene oxide (Great Lakes
Made, PO64P), brominated polystyrene (Ferro Corporation
Made of 68PB), antimony trioxide and glass fiber
Melt kneading and blending in the proportions shown in 1 using an extruder,
Flame retardant and thick by molding the reticle with an injection molding machine
Tensile strength of normal part and weld part with differently shaped pieces
Was evaluated. The results are shown in Table 1. From this result
When using Riphenylene oxide, brominated polystyrene
The weld strength of the thin wall (0.8 mm or less) is more specific than
It turns out that it is excellent. And this is the flame retardant aid
The same applies in the presence of agents and glass fibers
I also understand.

Examples 4 to 6 The compositions shown in Table 2 were evaluated in the same manner as in Example 1 by extrusion kneading, pelletizing, and injection molding. The results are shown in Table 2.
Both show excellent properties.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining a test piece for measuring the strength of a welded portion, and the unit of dimensions in the figure is mm. 1 ... Spray, 2 ... Runner, 3 ... Test piece, 4 ...
… Weld section.

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Claims (1)

[Claims] 1. 0 to 100 parts by weight of a composition comprising 50 to 95% by weight of polyamide, 5 to 35% by weight of optionally branched brominated polyphenylene oxide, and 0 to 15% by weight of metal oxide. A molded article obtained by injection-molding a flame-retardant polyamide resin composition containing 100 parts by weight of a reinforcing agent, having a thin-walled portion having a wall thickness of 0.8 mm or less, and a welded portion is present in the thin-walled portion. Flame-retardant polyamide molded product that does.