JPH06145508A - Flame-retardant polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition giving a molding prevented from both having a silver surface and decreasing in whiteness by mixing a specific polyamide resin, melamine cyanurate, and an organophosphorus compound in respective given amounts. CONSTITUTION:The composition comprises 100 pts.wt. polyamide resin in which 50-90% of the terminals have been aminated (e.g., nylon 66), 1-20 pts.wt. melamine cyanurate, and 0.001-1 pt.wt. organophosphorus compound, preferably at least one of a tris(alkylaryl) phosphite represented by formula I wherein R1 is an alkyl and R2 and R3 each is H or an alkyl, a pentaerythritol phosphite represented by formula II wherein R1 and R2 each is an alkyl, and an alkylenebis(alkylaryl) alkyl phosphite represented by formula III wherein R1 is an alkylene and R2 and R3 each is an alkyl.

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 excellent in the appearance of molded articles. Specifically, the present invention is flame-retardant and does not generate silver during molding,
Moreover, the present invention relates to a polyamide resin in which the color tone of the molded product is white and the appearance is excellent.

[0002]

2. Description of the Related Art Polyamide resins are used in the fields of automobile parts, electronic / electrical parts, mechanical parts, etc. due to their excellent mechanical properties, molding processability, chemical resistance and the like.

Of these, flame-retardant polyamide resins are widely used in fields requiring a high degree of flame-retardant property such as electronic and electrical parts, and it is difficult to blend melamine cyanurate in them. Flammable polyamide resins are known (Japanese Patent Laid-Open Nos. 53-125459 and 53-31).
759). This polyamide resin is an excellent resin composition having sufficient flame retardancy.

[0004]

However, these flame-retardant polyamide resins have the problems of appearance of silver on the surface of the molded product due to severe heat history during molding and poor whiteness. If the molding temperature is lowered in order to suppress the generation of silver on the surface of the molded product, it is difficult to obtain a molded product having a small thickness due to insufficient fluidity.

Further, it is already known to mix an inorganic phosphorus compound with a flame-retardant polyamide resin containing melamine cyanurate for the purpose of preventing reduction in whiteness at the time of molding (JP-A-3-76756). Issue). According to this method, reduction in whiteness can be prevented, but there is a problem that silver generation increases due to the addition of the inorganic phosphorus compound.

[0006]

Therefore, as a result of diligent studies on the above problems, the present inventors have found that the terminal amino group ratio is 5
It has been found that, by blending 0 to 90% of a polyamide resin with a specific organic phosphorus compound, it is possible to simultaneously suppress generation of silver on the surface of a molded article and prevent whiteness from decreasing, and complete the present invention. Came to.

That is, the present invention is: a polyamide resin 1 having a terminal amino group ratio of 50 to 90%.
(1) Melamine cyanurate 1 to 100 parts by weight
20 parts by weight and (2) organophosphorus compound 0.001
It is to provide a flame-retardant polyamide resin composition containing 1 to 1 part by weight. Also,

The organic phosphorus compound is represented by the following formula (1);

[Chemical 4]

(Wherein R ₁ represents an alkyl group, and R ₂ and R ₃ represent H or an alkyl group), and a tris (alkyl-aryl) phosphite and / or the following formula (2);

[Chemical 5]

(In the formula, R ₁ and R ₂ are alkyl groups and may be the same or different) and pentaerythritol phosphite and / or the following formula (3);

[Chemical 6]

(Wherein R ₁ is alkylene, R ₂ and R ₃
Is an alkyl group and may be the same or different), and is also an alkylenebis (alkyl-aryl) alkylphosphite.

The present invention will be described in more detail below. Examples of the polyamide resin applied to the composition of the present invention include polymers of ε-caprolactam, aminocaproic acid, enanthlactam, 7-aminopeptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid and the like.

Further, diamines such as hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine and metaxylenediamine,
Polymers obtained by polycondensation with dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid and glutaric acid, or copolymers thereof, or polymers or copolymers thereof All polyamide resins such as a mixture of

Polyamide resins which are particularly useful in the present invention include nylon 46, nylon 610 and nylon 61.
2. Polyamide resin such as nylon 66, nylon 66 / 6T copolymer, nylon 66/6 copolymer, etc., which is molded at a relatively high temperature.

The degree of polymerization of the polyamide resin used here is not particularly limited, and one having a sulfuric acid relative viscosity within the range of 1.5 to 4.5 can be arbitrarily used according to JIS K-6180 method. You can

The terminal amino group ratio is determined by measuring the concentrations of terminal amino groups and terminal carboxyl groups of the polyamide resin,
It is defined by the following formula 1.

[Equation 1]

Here, the terminal amino group ratio of the polyamide resin used is preferably in the range of 50 to 90%, and more preferably the terminal amino group ratio is 60 to 85%.

When the terminal amino group ratio is lower than 50%, the desired effect cannot be obtained, and when the terminal amino group ratio is 90% or more, the polymerization of polyamide is inhibited. The method of preparing the polyamide resin in the range of the terminal amino group ratio of 50 to 90% can be easily carried out by adding a compound of monoamine or diamine and its derivative.

As the compounds of monoamine and diamine,
Methylamine, ethylamine, propylamine, hexamethylenediamine, tetramethylenediamine, undecamethylenediamine, dodecamethylenediamine, m-xylenediamine, p-xylenediamine and their derivatives may be used alone or in combination of two or more.

These terminal amino group ratio regulators may be added at any stage before, during or after the polymerization. The melamine cyanurate (1) used in the present invention is an equimolar reaction product of melamine and cyanuric acid, and for example, an aqueous solution of melamine and an aqueous solution of cyanuric acid are mixed to obtain 90 to 1
A precipitate obtained by stirring at a temperature of about 00 ° C., filtering and drying the reaction product, and then finely pulverized may be used.

Further, some of the amino groups or hydroxyl groups in melamine cyanurate may be substituted with other substituents. The amount of melamine cyanurate used is 1 to 20 parts by weight, preferably 3 to 100 parts by weight, based on 100 parts by weight of the polyamide resin.
12 parts by weight.

If the amount used is too small, less than 1 part by weight, the effect of flame retardancy is small, and conversely, if the amount exceeds 20 parts by weight, the flame retardancy obtained is difficult to improve. The method of blending melamine cyanurate with the polyamide resin is
Any known method can be applied, but industrially, a method of melt mixing with a polyamide resin using an extruder or the like is preferable.

Examples of the organic phosphorus compound (2) include tris (alkyl-aryl) phosphites and / or pentaerythritol phosphite and / or alkylenebis (alkyl-aryl) alkylphosphites.

Examples of tris (alkyl-aryl) phosphites include tris (2,4-di-methylphenyl) phosphite, tris (2,4-di-ethylphenyl) phosphite and tris (2,4-). Examples thereof include di-propylphenyl) phosphite, and tris (2,4-di-t-butylphenyl) phosphite commercially available as “IRGAFOS168” from Nippon Ciba Geigy Co., Ltd.

Examples of the phosphite ester of pentaerythritol include bis (2,4,6-tri-methylphenyl) pentaerythritol-di-phosphite and bis (2,6-di-ethyl-4-methylphenyl). ) Pentaerythritol-di-phosphite, bis (2,6-di-propyl-4-methylphenyl) pentaerythritol-di-phosphite, and commercially available from Asahi Denka Co., Ltd. as "Adeka Stab PEP-36". Examples thereof include bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite.

Examples of the alkylenebis (alkyl-aryl) alkylphosphites include 2,2-methylenebis (4,6-di-propylphenyl) propylphosphite and 2,2-methylenebis (4,6-di-propyl). Phenyl) octyl phosphite, 2,2-ethylenebis (4,6-di-propylphenyl) octylphosphite, 2,2-methylenebis (4,6-di-methylphenyl) octylphosphite, and Asahi Denka Kogyo ( stock)
2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, which is commercially available as "Adeka Stab HP-10".

These organophosphorus compounds may be used alone or in combination with 100 parts by weight of polyamide resin in an amount of 0.001 to 0.001.
It is preferable to use 1 part by weight, preferably 0.01 to 0.8 part by weight.

The amount of the organic phosphorus compound compounded is 0.001
If the amount is less than 1 part by weight, it is not effective in preventing the whiteness from lowering. As a method of blending the organic phosphorus compound with the polyamide resin, various methods can be used at an arbitrary stage before molding.

For example, a method of dry blending with polyamide resin pellets or powder, a method of melt blending after dry blending with an extruder or the like to form pellets, a high concentration of an organophosphorus compound by melt mixing with an extruder or the like, and mastering Examples thereof include a method of blending as pellets.

The flame-retardant polyamide resin of the present invention contains various kinds of lubricants, antistatic agents, copper-based heat stabilizers, phenol-based stabilizers, ultraviolet absorbers, reinforcing agents, etc. to the extent that the effects of the present invention are not impaired. Additives can be added.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The flammability in the examples shows the result of the vertical burning test of UL-94 standard, and the silver length shows the molded product shown in FIG. 1 with a PS40E injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. at a cylinder temperature of 265. ℃, mold temperature 80 ℃, measuring stroke 60mm, cushion amount 13mm, injection speed 40%,
Molding was performed under the conditions of an injection pressure of 35%, an injection time of 10 seconds, a cooling time of 20 seconds, and a dwell time of 2 seconds, and the maximum value of the silver length generated at the flow front end of the molded product was measured.

As the test pieces for the flammability test and the whiteness measurement, a PS40E molded product of 5 × 1/2 × 1/16 inch was used.
Using a molding machine, cylinder temperature 265 ° C, mold temperature 80
Molding was carried out under conditions of ℃, measuring stroke 65 mm, cushion amount 10 mm, injection speed 40%, injection output 35%, injection time 10 seconds, cooling time 20 seconds, and rest time 2 seconds.

The whiteness was measured by measuring the Hunter whiteness using a color difference meter ND-1001DP manufactured by Nippon Denshoku Industries Co., Ltd. The higher the Hunter whiteness value, the whiter the color tone of the molded product.

(Examples 1 to 7) Hexamethylenediamine adipate was polymerized by adding a predetermined amount of hexamethylenediamine as a terminal amino group ratio adjusting agent, and the terminal amino group ratios were 64%, 75% and 83%, respectively. % Nylon 66 resin was obtained.

Further, these nylon 66 resins were blended with a predetermined amount of melamine cyanurate commercially available as "MC-White" from Nissan Chemical Industries, Ltd., and then melt-mixed with an extruder to obtain flame retardance. Nylon 66 resin pellets were obtained. The flame-retardant nylon 66 resin pellets were dry-blended with an organophosphorus compound, injection-molded, and subjected to silver length, Hunter whiteness and combustion test to obtain the results shown in Tables 1 and 2 below.

[0036]

[Table 1]

[0037]

[Table 2]

Comparative Example 1 Hexamethylenediamine adipate was added and polymerized with a predetermined amount of adipic acid as a terminal amino group ratio adjusting agent to obtain a nylon 66 resin having a terminal amino group ratio of 27%.

Furthermore, MC- is added to these nylon 66 resins.
After blending a predetermined amount of white, the same operation as in Examples 1 to 6 was carried out to obtain pellets of flame-retardant nylon 66 resin, and silver length, Hunter whiteness and combustion test were conducted in the same manner as in Examples 1 to 6. .

(Comparative Examples 2 to 3) The pellets of the flame-retardant nylon 66 resin obtained in Comparative Example 1 were dry-blended with an organophosphorus compound, and the same operations and tests as in Examples 1 to 6 were carried out.

(Comparative Example 4) The same flame-retardant nylon 66 resin pellets as in Example 1 were obtained, and the same silver length, Hunter whiteness and combustion test were conducted without adding an organophosphorus compound.

(Comparative Example 5) Flame-retardant nylon 6 of Comparative Example 4
After dry blending 6 resin pellets with sodium hypophosphite, the same silver length, Hunter whiteness and combustion test were conducted.

(Examples 8 to 9) 5 parts by weight of ε-caprolactam was added to 100 parts by weight of hexamethylenediamine adipate, and a predetermined amount of hexamethylenediamine was added as a terminal amino group ratio adjusting agent. Addition polymerization,
A 66/6 copolymer having a terminal amino group ratio of 63% was obtained.

Further, a predetermined amount of MC-white was blended with this copolymer, and the same procedure as in Example 1 was carried out to obtain pellets of flame-retardant nylon 66 resin. After dry blending an organic phosphorus compound thereto, the same operations and tests as in Examples 1 to 6 were performed.

(Comparative Examples 6 to 7) 5 parts by weight of ε-caprolactam was added to 100 parts by weight of hexamethylenediamine adipate, and a predetermined amount of adipic acid was added and polymerized as a terminal amino group ratio adjusting agent. A 66/6 copolymer having a terminal amino group ratio of 29% was obtained.

After blending a predetermined amount of MC-white with this copolymer, the same silver length, Hunter whiteness and burning test as in Comparative Examples 1 and 2 were conducted.

(Comparative Example 8) The same silver length, Hunter whiteness and burning test were carried out as in Example 7, except that the organophosphorus compound was not added.

[0048]

From the results shown in Table 1, the ratio of terminal amino groups was 50.
-90% polyamide resin, melamine cyanurate containing flame-retardant polyamide resin, only when a specific organophosphorus compound is blended to achieve the suppression of silver generation on the surface of the molded product and the reduction of whiteness at the same time It is clear that it is possible.

[Brief description of drawings]

FIG. 1 is a schematic view showing a silver length of each molded product test piece used in a vertical combustion test in Examples.

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[Procedure amendment]

[Submission date] February 9, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

The amino group in melamine cyanurate
Or, some of the hydroxyl groups are replaced by other substituents
You may stay. The amount of melamine cyanurate used is 1 to 20 parts by weight, preferably 3 to 12 parts by weight, based on 100 parts by weight of the polyamide resin.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

[0036]

[Table 1]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

[0037]

[Table 2]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

Furthermore, MC- is added to these nylon 66 resins.
After a predetermined amount of blending the white, the same operation as in Example 1 to 7 to obtain a pellet of the flame-retardant nylon 66 resin, Silver length in the same manner as in Example 1 to 7 were subjected to Hunter whiteness and combustion test .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction content]

Comparative Examples 2 to 3 After the organic phosphorus compound was dry blended with the pellets of the flame-retardant nylon 66 resin obtained in Comparative Example 1, the same operations and tests as in Examples 1 to 7 were performed.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

Further, a predetermined amount of MC-white was blended with this copolymer, and the same procedure as in Example 1 was carried out to obtain pellets of flame-retardant nylon 66 resin. After the organic phosphorus compound was dry-blended to this, the same operations and tests as in Examples 1 to 7 were performed.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction content]

Comparative Example 8 The same silver length, Hunter whiteness and combustion test were carried out as in Example 8 without adding the organophosphorus compound.

Claims (2)

[Claims] (1) 1 to 20 parts by weight of melamine cyanurate and (2) 0.001 to 1 parts by weight of an organophosphorus compound with respect to 100 parts by weight of a polyamide resin having a terminal amino group ratio of 50 to 90%. A flame-retardant polyamide resin composition containing a part. 2. An organic phosphorus compound is represented by the following formula (1); (In the formula, R ₁ represents an alkyl group, R ₂ and R ₃ represent H or an alkyl group) and / or tris (alkyl-aryl) phosphite and the following formula (2); (In the formula, R ₁ and R ₂ are alkyl groups and may be the same or different), and phosphite ester of pentaerythritol and / or the following formula (3); (Wherein R ₁ is alkylene, R ₂ and R ₃ are alkyl groups, and may be the same or different), and are alkylenebis (alkyl-aryl) alkylphosphites. The flame-retardant polyamide resin composition according to claim 1.