JPH05320503A - Flame-retardant polyamide resin composition - Google Patents

Abstract

PURPOSE:To provide a flame-retardant polyamide resin composition which comprises a specific crystalline polyamide resin, a specific polybrominated styrene and an auxiliary flame retardant thus shows excellent flame retardancy and heat resistance and gives moldings of good surface appearance. CONSTITUTION:The objective resin composition comprises (A) 100 pts.wt. of a crystalline polyamide resin which is constituted with the recurring units of formula I to formula III (R is an aliphatic group of 6 to 18C; R<1> is an aliphatic group of 4 to 18C or m-phenylene group; (n) is an integer of 5 to 18) and contains the units of formula I or formulas I and II, as essential units, and has a melting point higher than 270 deg.C, (B) 0.5 to 60 pts.wt. of polybromostyrene which is prepared from brominated styrene, has the unit of formula IV as the major component, 1X10<3> to 30X10<4> number-average molecular weight and 2X10<3> to 120X10<4> weight-average molecular weight, and (C) 1 to 10 pts.wt. of an auxiliary flame retarant selected from antimont oxide, sodium antimonate, tin oxide, iron oxide, zinc oxide and zinc borate preferably anhydrous sodium antimonate, and, when needed, fillers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyamide resin composition having excellent stability when melted, and more specifically, it has high heat resistance such as solder resistance and is decomposed and deteriorated during melt molding. The present invention relates to a flame-retardant polyamide resin composition having no melt stability and good melt stability.

[0002]

2. Description of the Related Art Copolyamide prepared by copolymerizing hexamethylene terephthalamide and hexamethylene isophthalamide, copolyamide prepared by copolymerizing hexamethylene terephthalamide and hexamethylene adipamide, or hexa It is known that a copolyamide obtained by copolymerizing methylene terephthalamide and caproamide has good heat resistance and moldability (JP-A-60-
163927, JP-A-60-206827, JP-A-61-159422, and JP-A-61-2.
No. 83653).

In recent years, underwriters laboratories standard U.
High flame retardancy based on the L-94 standard is required, and various halogen-based flame retardants have been proposed for this.

Conventionally, as a method for making a polyamide flame-retardant, it has been known to blend an organic halogen compound like other synthetic resins (Japanese Patent Laid-Open Nos. 48-90338 and 51-39739). Bulletin).

It is known to blend brominated polystyrene into a polyamide as a flame retardant, and further blend a metal oxide as a flame retardant aid (JP-A-51-1403).
JP-A-51-4703, JP-A-51-47044
Publication).

A composition comprising polyamide and brominated polyphenylene ether (Japanese Patent Laid-Open No. 54-116054).
(Japanese Patent Application Laid-Open No. JP-A-2004) or a composition as described above, and attempts to improve the composition by adding additives (JP-A-58-84854, JP-A-62-223260, JP-A-1-1).
No. 38264) has been proposed.

[0007]

However, also in the technique of blending brominated polystyrene as a flame retardant, the processing temperature must be increased when the melting point of polyamide is high, which leads to deterioration of mechanical properties during molding retention and color tone. The actual situation is that the deterioration becomes large (Japanese Patent Laid-Open No. 51-1403 and Japanese Patent Laid-Open No. 51-403).
-4703, JP-A-51-47044).

Similarly, regarding flame retardants such as tribromoaniline, perchloropentacyclodecane, and decabromobiphenyl ether, thermal stability is not said to be good, and extrusion molding and injection are carried out under relatively high temperature conditions. In a molding process such as molding, it is not preferable because it is decomposed and the desired flame retardancy is not obtained, and further the physical properties of the molded product are significantly deteriorated and the working environment is contaminated.

Further, among organic halogen compounds, there are some organic halogen compounds which, upon combustion, thermally decompose to generate hydrogen halide, which accelerates the decomposition of amide bonds and makes the polyamide flammable. JP-A-48-90338 and JP-A-51-39739).

On the other hand, when the glass fiber is not mixed, the molded product showing flame retardancy equivalent to V-2 in the UL-94 standard is less likely to drop the melt by mixing the glass fiber. On the other hand, since the glass fiber acts like a wick, it continuously burns, resulting in UL-94.
The standard V-2 may not be maintained in some cases.

In consideration of the above circumstances, the present inventors have found that a flame-retardant polyamide resin composition having a high degree of heat resistance and flame retardancy, an extremely small loss on heating and a good appearance of a molded article. Earnestly studied in order to obtain.

[0012]

As a result of studies to solve the above problems, the present inventors have solved all the problems by combining a specific polyamide with a specific flame retardant, a flame retardant aid, a filler and the like. The inventors have found what can be done and have reached the present invention.

That is, the present invention provides (A) the following (I) to (I
Iterative component of II)

[Chemical 5]

[Chemical 6]

[Chemical 7] (In the formula, R is an aliphatic group having 6 to 18 carbon atoms, R'is an aliphatic group having 4 to 18 carbon atoms or an isophthalic group, and n is 5 to 1
Represents an integer of 8. ), (I) or (I)
And (II) as essential components, and melting point (T
crystalline polyamide resin 100 having m) of 270 ° C. or higher
Based on parts by weight, the following structural unit produced from (B) brominated styrene monomer

[Chemical 8] Having a number average molecular weight (Mn) of 1 × 10 5 as a main constituent
³ to 30 × 10 ⁴ , weight average molecular weight (Mw) of 2 × 10
Polybrominated styrene 0.5 to ^{3 to} 120 × 10 ⁴
60 parts by weight and (C) 1 to 10 parts by weight of at least one flame retardant aid selected from antimony oxide, sodium antimonate, tin oxide, iron oxide, zinc oxide, zinc borate. Flame-retardant polyamide resin composition.

The crystalline polyamide resin used in the present invention is (I) an aliphatic alkylene terephthalamide unit synthesized from an aliphatic alkylenediamine having 6 to 18 carbon atoms and terephthalic acid, and (II) having 6 to 18 carbon atoms. Aliphatic alkylene isophthalamide unit synthesized from aliphatic alkylene diamine and isophthalic acid, or 6 to 18 carbon atoms
Of the aliphatic alkylenediamine of (4) and an aliphatic alkylenedicarboxylic acid having 4 to 18 carbon atoms, (III) lactam, or an aliphatic aminocarboxylic acid component unit having 5 to 18 carbon atoms, (I) or , (I) and (I
It is a condensate containing I) as an essential component.

Specific examples of the aliphatic alkylenediamine having 6 to 18 carbon atoms include 1,6-diaminohexane, 1,
7-diaminoheptane, 1,8-diaminooctane,
1,9-diaminononane, 1,10-diaminodecane,
1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane , 1,18-diaminooctadecane and the like.

Specific examples of the aliphatic alkylenedicarboxylic acid having 4 to 18 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and praciline. Acid, tetradecanedioic acid, pentadecanedioic acid, octadecanedioic acid and the like.

Specific examples of lactams include ε-caprolactam, ζ-enanthlactam, η-capryllactam and ω-laurolactam.

Specific examples of the aliphatic aminocarboxylic acid having 5 to 18 carbon atoms include 6-aminocaproic acid and 11
-Aminoundecanoic acid, 12-aminododecanoic acid and the like. The crystalline polyamide resin of the present invention contains (I) or (I) and (II) as an essential component, and
A crystalline polyamide resin having a melting point (Tm) of 270 ° C. or higher, (I) may be alone, or (I) /
The binary copolymer polyamide of (II) or (I) / (III) or the ternary copolymer polyamide of (I) / (II) / (III) may be used.

The degree of polymerization of the crystalline polyamide resin used here is not particularly limited, and usually the relative viscosity (1 g of polymer is dissolved in 100 ml of 98% concentrated sulfuric acid and measured at 25 ° C., the same applies hereinafter) is 1. Those in 5 to 5.0 can be arbitrarily used.

The flame retardant used in the present invention has a number average molecular weight (Mn) of 1 × 10 ³ to 30 ×, which has the structural unit produced from brominated styrene monomer as a main constituent.
10 ⁴ , weight average molecular weight (Mw) is 2 × 10 ^{3 to} 120
It is a polybrominated styrene of × 10 ⁴ .

In general, a brominated polystyrene produced by radically or anionically polymerizing a styrene monomer and brominating the obtained polystyrene is blended, and the brominated polystyrene has a mechanical property during molding retention. In the present invention, it is essential to use polybrominated styrene obtained by polymerizing a brominated styrene monomer, because the deterioration and deterioration of color tone are large.

The polybrominated styrene is usually produced by radical polymerization or anionic polymerization, preferably radical polymerization.

The polybrominated styrene represented by the above general formula and used in the present invention preferably contains dibrominated styrene units in an amount of 60% by weight or more, and particularly preferably 70% by weight or more. .. It is polybrominated styrene obtained by copolymerizing 40% by weight or less, preferably 30% by weight or less of monobrominated styrene and / or tribrominated styrene in addition to dibrominated styrene.

The Mn of this polybrominated styrene is 1 × 10.
³ to 30 × 10 ⁴ , Mw is 2 × 10 ^{3 to} 120 × 1
0 ⁴ , preferably Mn of 1 × 10 ⁴ to 30 × 10 ⁴ , M
w is 2 × 10 ^{4 to} 120 × 10 ⁴ , particularly preferably Mn
Is 1 × 10 ⁴ to 15 × 10 ⁴ , and Mw is 2 × 10 ^{4 to} 60.
It is × 10 ⁴ .

The Mw / Mn ratio is preferably 1.5 to 5.0, and particularly preferably 2.0 to 4.0.

If the Mn is less than 1 × 10 ³ or the Mw is less than 2 × 10 ³ , the mechanical properties of the molded product and the solder heat resistance are deteriorated, which is not preferable. On the other hand, Mn is 30 × 1
When it is larger than 0 ⁴ or Mw is larger than 120 × 10 ⁴ , the composition of the present invention has poor fluidity, which is not preferable.

The polybrominated styrene preferably has an apparent density of 1.0 g / cm ³ or more, a solid density of 1.1 g / cm ³ or more, and an apparent density of 1.1 g / cm ³ or more, a solid density of 1.2 g / cm ^3. cm ³ or more is particularly preferable.

Further, the polybrominated styrene has an average diameter of 20 μm or less, preferably 10 μm in the polyamide resin composition.
It is preferably dispersed below.

The number average molecular weight is a value measured by gel permeation chromatography and is a relative value based on polystyrene molecular weight.

The amount of polybrominated styrene added is 0.5 to 60 parts by weight, preferably 1 to 20 parts by weight, particularly preferably 2 to 100 parts by weight of the polyamide resin.
15 parts by weight. If it is less than 0.5 part by weight, the flame retardant effect is insufficient, and if it is more than 60 parts by weight, mechanical and thermal properties are deteriorated, which is not preferable.

In the polyamide resin composition of the present invention, in addition to the flame retardant, at least one flame retardant auxiliary selected from antimony oxide, sodium antimonate, tin oxide, iron oxide, zinc oxide and zinc borate is used. In particular, sodium antimonate antimonate, particularly, substantially anhydrous sodium antimonate heat-treated at a high temperature of 550 ° C. or higher is preferable.

The amount of the flame retardant aid of the present invention added is 1 to 1.
It is 0 parts by weight, preferably 2 to 8 parts by weight.

In the present invention, various fillers can be added. The amount of the filler is 0 to 200 parts by weight with respect to 100 parts by weight of the polyamide resin, and the glass fiber, potassium titanate fiber, gypsum fiber, brass fiber, stainless fiber, steel fiber, ceramic fiber, boron whisker fiber, Mica, talc, silica, calcium carbonate,
Examples thereof include glass beads, glass flakes, glass microballoons, clay, wollastonite, titanium oxide, and other fibrous, powdery, granular, or plate-like inorganic fillers and other polymer fibers (carbon fibers).

Among the above fillers, glass fiber is preferably used. The glass fiber can be selected and used from long fiber type, short fiber type chopped strand, milled fiber, etc., but the average fiber diameter of the glass fiber is not limited to the surface appearance of the molded product and the point of improving the moldability. From the viewpoint of flame retardancy, 3 or more and less than 15 μm, particularly 3 or more and less than 11 μm, and more preferably 3 or more and less than 8 μm are preferable.

The length of the glass fiber is 30 or more and 10 ⁴
It is less than μm, particularly 1,000 or more and less than 4,000 μm.

If the average fiber diameter is larger than 15 μm, the moldability is deteriorated, the surface appearance is deteriorated, and the flame retardancy is not preferable either. The amount of the filler added is preferably 5 to 200 parts by weight, and particularly preferably 15 to 150 parts by weight, based on 100 parts by weight of the polyamide resin.

The glass fiber may be coated or bundled with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or a coupling agent such as a silane-based or titanate-based coupling agent. , And may be treated with other surface treatment agents.

The composition of the present invention contains an antioxidant and a heat stabilizer (eg, hindered phenol type, hydroquinone type, phosphite type and substitution products thereof, iodine, etc.) within a range not impairing the object of the present invention. Copper oxide, potassium iodide, etc., UV absorbers (eg resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, hindered amine-based, etc.), lubricants and mold release agents (montanic acid and its salts, its esters, its half esters) , Stearyl alcohol, stearamide and polyethylene wax), dyes (eg nigrosine) and pigments (eg cadmium sulfide, phthalocyanine, carbon black etc.), colorants including plasticizers, antistatic agents and other usual additives and other Add a thermoplastic resin It is possible to impart the characteristics.

In addition to the flame retardant of the present invention, a flame retardant such as brominated polycarbonate, brominated polyphenylene ether, brominated epoxy polymer, brominated polystyrene, or oligomer or phosphorus compound may be added together.

The polyamide resin composition of the present invention is preferably melt-kneaded, and a known method can be used for melt-kneading. For example, a Banbury mixer, rubber rolls, kneader, single-screw or twin-screw extruder, etc. can be used to melt-knead at a temperature of 200 to 370 ° C. to obtain a composition.

[0041]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Each evaluation was measured according to the method described below.

(1) Vertical Burning Test The test was carried out according to the UL-94 standard as shown below.

The upper end of the test piece is clamped, the test piece is set vertically, and a predetermined flame is applied to the test piece for 10 seconds to separate the test piece, and the burning time (first time) of the test piece is measured. Immediately after digestion, a flame is applied from the lower end for 10 seconds and then removed, and the burning time (second time) of the test piece is measured. 5 operations in total
Perform on one piece to obtain a total of 10 data.

Of the 10 data, the maximum value is M and the total is T. If M is 10 seconds or less and T is 50 seconds or less, the test piece does not burn up to the clamp, the melt falls, and if the cotton below is not ignited, it is equivalent to V-0. M is 30 seconds or less, T is 2
In 50 seconds or less, the test piece did not burn up to the clamp, the melt fell, and if the lower cotton was not ignited, it was equivalent to V-1. M
Is 30 seconds or less and T is 250 seconds or less, the test piece does not burn up to the clamp, the melt falls, and the cotton below is ignited, which is equivalent to V-2.

(2) Appearance of molded product A combustion test piece was injection-molded, and the surface of the molded piece was rough, air bubbles,
I saw the color tone. The results are shown by the following symbols. ◯: Glossy and smooth surface. Δ: The surface is smooth although the gloss is reduced. X: There is no gloss and the surface is rough.

(3) Loss on heating Using a TG / DTA-200 type manufactured by Seiko Denshi Kogyo Co., Ltd., a heating rate of 20 ° C./min and N _{2 of} 70 ml / mi.
The loss on heating at 380 ° C. was measured by n.

○: 1.0 wt% or less △: 1.0 to 3.0 wt% ×: 3.0 wt% or more

(4) Melting Point (Tm) Using DSC (PERKIN-ELMER type 7), 8 to 10 mg of a sample was measured at a temperature rising rate of 20 ° C./min and the temperature showing the maximum value of the melting curve was calculated as (Tm). -1). 8 to 10 mg of sample is heated at a heating rate of 20 ° C / min
Heated at (Tm-1) + 20 ° C for 5 minutes, then
After cooling to 30 ° C. at a temperature decreasing rate of 20 ° C./min, holding for 5 minutes, heating again at a temperature rising rate of 20 ° C./min (T
m-1) Heat to + 20 ° C. The temperature showing the maximum value of the melting curve at this time was defined as (Tm).

Examples 1 to 12 Copolymerization ratio of hexamethylene terephthalamide and hexamethylene adipamide (hereinafter referred to as 6T / 66) is 65/35% by weight, hexamethylene terephthalamide and caproamide. The copolymerization ratio of the copolymerized polyamide (hereinafter referred to as 6T / 6) is 75/25.
% By weight, a copolyamide composed of hexamethylene terephthalamide and hexamethylene isophthalamide (hereinafter referred to as 6
T / 6I) copolymerization ratio of 65/35% by weight, dodecamethylene terephthalamide (hereinafter referred to as 12T),
The copolymerization ratio of hexamethylene terephthalamide, hexamethylene isophthalamide and aminododecanoic acid (hereinafter referred to as 6T / 6I / 12) is 69.
/ 18/13% by weight, and the copolymerization ratio of octamethylene terephthalamide and hexamethylene isophthalamide (hereinafter referred to as 8T / 6I) is 80/2.
0% by weight of 6 levels of polyamide and copolyamide pellets, length 3 mm, glass fiber chopped strands 13 μm in diameter, dibrominated styrene 80 as flame retardant
Polybrominated styrene having a number average molecular weight of 10 × 10 ⁴ and a weight average molecular weight of 30 × 10 ⁴ , obtained by polymerizing a monomer containing 15% by weight, 15% by weight of monobrominated styrene and 5% by weight of tribrominated styrene. , Antimony trioxide as a flame retardant aid, and soda antimonate were mixed in the proportions shown in Table 1, and then a cylinder temperature condition of 260 to 335 ° C. was obtained using a vent type twin screw extruder of 30 mmφ. And melt mixed. The mixture was molded by an injection molding machine to prepare a test piece.

Table 1 shows the evaluation results of the obtained test pieces.

These compositions were excellent in heat resistance, flame retardancy and appearance of molded products.

[0053]

[Table 1]

Comparative Examples 1 to 8 The polyamides and copolyamides used in the examples, glass fibers and antimony trioxide were used, and brominated polystyrene, brominated polycarbonate, perchlorocyclopentadecane and brominated epoxy were used as flame retardants. Table 2 shows the results of the test pieces prepared and evaluated in the same manner as in 1 to 12.

The one using brominated polycarbonate as the flame retardant is (6T / 66 = 65 /
35, 6T / 6 = 75/25, 6T / 6I = 65/35
(% By weight of copolyamide) A test piece having excellent thermal decomposition and foaming could not be obtained. (Comparative Examples 1, 2, and 3) Those using perchlorocyclopentadecane (12T, 6T / 6I / 12 = 69) when the temperature during melt mixing was high.
(18/13 wt% copolyamide) Pellets with excellent thermal decomposition could not be obtained. (Comparative Examples 5 and 6) In the case of using brominated epoxy, thickening due to gelation was remarkable at the stage of melt mixing, and good pellets could not be obtained. (Comparative Example 7) The weight loss on heating was 3.0 for those using brominated polystyrene.
It was not less than wt%, and the desired physical properties were not obtained.
(Comparative Example 4) Polybrominated styrene was used in an amount of 0.5 parts by weight or less based on the copolyamide, which was a level unacceptable to the V-0 standard, and the desired physical properties were not obtained. (Comparative Example 8)

[Table 2]

[0056]

INDUSTRIAL APPLICABILITY The flame-retardant polyamide resin composition of the present invention makes it possible to obtain an injection-molded article having high heat resistance, flame retardancy, and a good molding surface appearance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C08L 25:18) 9166-4J

Claims (1)

[Claims] (A) The following repeating components (I) to (III): [Chemical 2] [Chemical 3] (In the formula, R is an aliphatic group having 6 to 18 carbon atoms, R'is an aliphatic group having 4 to 18 carbon atoms or a metaphenylene group, and n is 5
Represents an integer of -18. ), (I) or,
Crystalline polyamide resin 1 containing (I) and (II) as essential components and having a melting point (Tm) of 270 ° C. or higher.
Based on 100 parts by weight, (B) the following structural unit prepared from brominated styrene monomer: Having a number average molecular weight (Mn) of 1 × 10 5 as a main constituent
³ to 30 × 10 ⁴ , weight average molecular weight (Mw) of 2 × 10
Polybrominated styrene 0.5 to ^{3 to} 120 × 10 ⁴
60 parts by weight and (C) 1 to 10 parts by weight of at least one flame retardant aid selected from antimony oxide, sodium antimonate, tin oxide, iron oxide, zinc oxide and zinc borate. Flame-retardant polyamide resin composition.