JPH0718179A - Flame retardant polyamide resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition capable of simultaneously achieving the improvement in heat resistance, prevention of deterioration in whiteness and excellent molding processability in molding only when a polyamide resin containing melamine cyanurate is blended with a specific phosphorus-based compound, a specified phenolic compound and a metallic salt of a >=22C aliphatic carboxylic acid. CONSTITUTION:This flame retardant polyamide resin composition contains 100 pts.wt. polyamide resin, (1) 1-20 pts.wt. melamine cyanurate, (2) 0.001-5 pts.wt. phosphorus-based compound, (3) 0.001-1 pt.wt. phenolic compound and (4) 0.02-0.5 pt.wt. metallic salt of a >=22C aliphatic carboxylic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant polyamide resin composition having excellent moldability. More specifically, the present invention relates to a polyamide resin composition which is flame-retardant, has good heat resistance, and exhibits excellent productivity during injection molding.

[0002]

2. Description of the Related Art Polyamide resins are used in the fields of automobile parts, electric / electronic parts, etc. due to their excellent mechanical properties, moldability and chemical resistance. Of these, flame-retardant polyamide resins are widely used in fields requiring high flame-retardant properties such as electrical and electronic parts, and among them flame-retardant polyamide resins containing melamine cyanurate. Are known (Japanese Patent Laid-Open Nos. 53-125459 and 53-31759). This polyamide resin is an excellent resin composition having sufficient flame retardancy.

[0003]

However, these flame-retardant polyamide resins have a problem of poor appearance in which the whiteness of the surface of a molded product is lowered due to a severe heat history during molding. Further, a flame-retardant polyamide resin containing an inorganic phosphorus compound and melamine cyanurate for the purpose of preventing a decrease in whiteness at the time of molding is already known (JP-A-3-76756).
Issue). According to this method, it is possible to prevent a decrease in whiteness, but there is a problem that the heat resistance is not sufficient and the moldability is poor.

[0004]

Therefore, as a result of intensive investigations by the present inventors, a specific phosphorus compound, a specific phenolic compound, and a metal salt of an aliphatic carboxylic acid having 22 or more carbon atoms are mixed in a polyamide resin. By doing so, they have found that improvement in heat resistance, prevention of whiteness reduction during molding, and excellent moldability can be achieved at the same time, and the present invention has been achieved.

That is, the present invention relates to 100 parts by weight of polyamide resin, (1) 1 to 20 parts by weight of melamine cyanurate (2) 0.001 to 5 parts by weight of phosphorus compound (3) 0.001 of phenolic compound To 1 part by weight (4) Metal salt of aliphatic carboxylic acid having 22 or more carbon atoms
It is intended to provide a flame-retardant polyamide resin composition containing 0.02 to 0.5 part by weight. Also,

Specifically, the phosphorus compound is a metal salt of hypophosphorous acid and / or the following formula (1);

[Chemical 5]

(In the formula, R ₁ is an alkyl group, and R _1
2 , R ₃ represents H or an alkyl group) and / or tris (alkyl-aryl) phosphite represented by the formula (2);

[Chemical 6]

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

[Chemical 7]

(Wherein R ₁ is alkylene and R ₁ is
There is also provided a flame-retardant polyamide resin composition, which is an alkylenebis (alkyl-aryl) alkylphosphite represented by ₂ and R ₃ are alkyl groups and may be the same or different. It is also characterized in that the phenolic compound is a hindered phenol represented by the following formula (4).

[Chemical 8]

[In the formula, R ₁ and R ₂ are alkyl groups and may be the same or different. And A is -NH,
-NHC _m H _2m (wherein m represents an integer of 2 to 8) represents a group selected from the group consisting of. ]

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, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanedioic acid,
All polyamide resins such as polymers obtained by polycondensing dicarboxylic acids such as glutaric acid, copolymers thereof, and mixtures of these polymers or copolymers can be mentioned.

As the polyamide resin used in the present invention, nylon 46, nylon 610, nylon 612,
Nylon 66, Nylon 66 / 6T, Nylon 66/6
A polyamide resin that is molded at a relatively high temperature such as a copolymer is desirable. The degree of polymerization of the polyamide resin used here is not particularly limited, and those having a relative viscosity of JIS K-6180 sulfuric acid of 1.5 to 4.5 can be arbitrarily used.

The melamine cyanurate used in the present invention is an equimolar reaction product of melamine and cyanuric acid. For example, an aqueous solution of melamine and an aqueous solution of cyanuric acid are mixed at a temperature of about 90 to 100 ° C. It is possible to use a finely pulverized product after filtering and drying the precipitate formed by the reaction by stirring. Further, some of the amino groups or hydroxyl groups in melamine cyanurate may be substituted with other substituents. Of course, a commercially available product can be used as it is or after being crushed.

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. If the amount used is too small, the effect as flame retardancy is small, and conversely if the amount is too large, the flame retardancy obtained is not further improved. Any known method can be applied to blend the melamine cyanurate into the polyamide resin, but industrially, a method of melt-mixing the polyamide resin with an extruder or the like is preferable.

The phosphorus compounds used in the present invention include metal salts of hypophosphorous acid and / or tris (alkyl-aryl) phosphites and / or phosphite esters of pentaerythritol and / or alkylenebis ( Alkyl-aryl) alkyl phosphites are useful.

Examples of metal salts of hypophosphite include potassium hypophosphite, sodium hypophosphite, calcium hypophosphite, barium hypophosphite, manganese hypophosphite, magnesium hypophosphite, hypophosphite. Aluminum phosphate etc. are mentioned.

Examples of tris (alkyl-aryl) phosphites include tris (2,4-di-methylphenyl) phosphite, tris (2,4-di-ethylphenyl) phosphite, tris (2,4-). Examples include di-propylphenyl) phosphite and tris (2,4-di-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

Asahi Denka Kogyo Co., Ltd. ADEKA STAB PEP
Bis (2,6-di-t-4 marketed as -36
-Methylphenyl) pentaerythritol-di-phosphite and the like.

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) octyl phosphite, and Adekastab HP- from Asahi Denka Co., Ltd.
2,2-methylenebis (4, which is commercially available as
6-di-t-butylphenyl) octyl phosphite sulphide and the like can be mentioned.

The amount of the phosphorus compound used in the present invention is 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, alone or in combination with 100 parts by weight of the polyamide resin. If the amount used is too small, the effect of preventing a decrease in whiteness during molding is small, and conversely if the amount is too large, the effect of preventing a decrease in whiteness obtained is not further improved.

As a method for incorporating the phosphorus compound into the polyamide resin, various methods can be used at an arbitrary stage before molding. For example, a method of dry blending with pellets or powder of a polyamide resin, a method of melt blending after dry blending with an extruder or the like to form pellets, a high concentration phosphorus compound is melt mixed with an extruder or the like and blended as a master pellet. And the like.

Examples of the phenolic compounds used in the present invention include N, N'-hexamethylenebis (3,3)
5-di-methyl-4-hydroxy-hydrocinnamamide), N, N'-hexamethylene bis (3,5-di-ethyl-4-hydroxy-hydrocinnamamide), and

IRGANO from Japan Ciba-Geigy Co., Ltd.
X1098 commercially available N, N'-hexamethylenebis (3,5-di-t-4-hydroxy-hydrocinnamide) and IRGANOX MD1024 commercially available N, N'-bis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and the like.

The amount of the phenolic compound used in the present invention is 0.0 based on 100 parts by weight of the polyamide resin.
The amount is 01 to 1 part by weight, preferably 0.01 to 0.8 part by weight. If the amount used is too small, the heat resistance effect is difficult to obtain, and conversely, if the amount is too large, the heat resistance effect obtained is not further improved.

As a method of blending the phenolic 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 method of melt blending a high-concentration phenolic compound with an extruder or the like, and blending as a master pellet Etc.

Specific examples of the metal salt of an aliphatic carboxylic acid having 22 or more carbon atoms used in the present invention include metal salts such as behenic acid, lignoceric acid, cerotic acid, montanic acid, and melissic acid. Industrial sodium montanate and HOSTAL commercially available as HostalubNaV101 from Hoechst Japan KK
Examples thereof include industrial calcium montanate marketed as UBCaV102.

The amount of the metal salt of an aliphatic carboxylic acid having 22 or more carbon atoms used in the present invention is 100% polyamide resin.
The amount is 0.02 to 0.5 part by weight, preferably 0.04 to 0.3 part by weight. If the amount used is too small, the effect of improving the moldability is small, and conversely if the amount is too large, the effect of improving the moldability obtained is not improved.

As a method of blending a metal salt of an aliphatic carboxylic acid having 22 or more carbon atoms into a polyamide resin, the effect of the present invention becomes more effective by adhering it to the pellet surface. Therefore, a dry blend using a blender or the like. The method of blending, the method of blending with a blended oil such as mineral oil or polyethylene glycol, or the method of coating the pellet surface is preferable.

The flame-retardant polyamide resin of the present invention may contain additives such as a lubricant, an antistatic agent, a copper-based stabilizer, and a reinforcing agent to the extent that the effects of the present invention are not impaired.

[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. <Measurement method> Plasticization time: The plasticization time is based on ASTM-D790. The molded product of the tensile test is PS manufactured by Nissei Plastic Industry Co., Ltd.
Cylinder temperature 265 using -40E injection molding machine
Molding under conditions of ℃, mold temperature 80 ℃, measuring stroke 60 mm, cushion amount 13 mm, injection speed 40%, injection pressure 35%, injection time 10 seconds, cooling time 20 seconds, pause 2 seconds,
The average value and the deviation value of the plasticizing time from the 31st shot to the 40th shot from the start of molding were measured. The smaller the average value and the deviation value of the plasticizing time, the better the moldability.

Mold release force: The mold release force was the cup-shaped molded product shown in FIG. 1 using an IS90B injection molding machine manufactured by Toshiba Machine Industry Co., Ltd., with a cylinder temperature of 265 ° C. and a mold temperature of 80 ° C.
Measuring stroke 33mm, injection speed 50%, injection pressure 3
Molding was performed under the conditions of 15 kg / cm ² , injection time of 5 seconds, cooling time of 10 seconds, and rest of 2 seconds, and the average value of the releasing force from the 31st shot to the 35th shot from the start of molding was measured. Note that the smaller the average value of the releasing force is, the better the moldability is.

Heat resistance: The heat resistance was evaluated by allowing the molded product molded in the plasticity evaluation to stand in a hot air oven whose temperature was adjusted to 150 ° C. for 5 days, and conducting a tensile test according to ASTM-D790. The comparison was made by the retention rate of tensile strength.
The higher the retention rate of tensile strength, the better the heat resistance.

Whiteness: 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, the whiter the color tone of the molded product.

(Example 1) Various additives shown in Table 1 were blended in predetermined amounts and then melt-mixed using an extruder to obtain pellets of a flame-retardant polyamide resin. The pellets were dry-blended with a metal salt of an aliphatic carboxylic acid having a carbon number of C22 or more, and then injection-molded to evaluate the plasticizing time, release force, tensile strength, and Hunter whiteness.

Comparative Examples 1 and 2 After the flame retardant polyamide resin pellets obtained in Example 1 were dry-blended with a metal salt of an aliphatic carboxylic acid having a C21 or less, the same evaluation as in Example 1 was carried out. .

Comparative Example 3 The same evaluation as in Example 1 was carried out without dry blending the metal salt of the aliphatic carboxylic acid to the pellets of the flame-retardant polyamide resin obtained in Comparative Example 1.

(Examples 2 to 4) After pellets of flame-retardant polyamide resin obtained by the same procedure as in Example 1 were dry-blended while changing the amount and type of the metal salt of C22 or more aliphatic carboxylic acid used. The same evaluation as in Example 1 was performed.

(Examples 5 to 9) After obtaining pellets of a flame-retardant polyamide resin having different amounts and types of phosphorus compounds used in the same manner as in Example 1, the same evaluation as in Example 1 was performed. .

(Examples 10 to 12) Pellets of flame-retardant polyamide resin having different amounts and types of phenolic compounds used were obtained in the same manner as in Example 1, and the same evaluation as in Example 1 was performed. .

Comparative Examples 4 to 6 After obtaining pellets of a flame-retardant polyamide resin containing no additive, the same evaluation as in Example 1 was carried out.

[0042]

[Table 1]

[0043]

[Table 2]

Ny. 66; Asahi Kasei Co., Ltd. 1200-011 Melamine cyanurate; Mitsubishi Petrochemical Co., Ltd. MCA
-CO Irganox 1098, Irgafos 168; Nippon Ciba Geigy KK Adeka Stab PEP-36, Adeka Stab HP-10;
Asahi Denka Kogyo Co., Ltd. Hostalub Nav101, Hostalub
Cav101; manufactured by Hoechst Japan Ltd.

[0045]

From the results shown in Tables 1 and 2, only when a specific phosphorus compound, a specific phenol compound and a metal salt of an aliphatic carboxylic acid having a carbon number of C22 or more are blended with a polyamide resin containing melamine cyanurate, It is clear that improvement of heat resistance, prevention of whiteness reduction during molding, and excellent moldability are achieved at the same time.

[Brief description of drawings]

FIG. 1 shows a drawing of a mold for evaluating a releasing force of the present invention.

[Explanation of symbols] 1 nozzle of injection molding machine 2 sprue runer 3 molded product (cup shape) 4 eject turbine 5 ejector plate 6 pressure sensor 7 knockout rod 8 cavity 9 core 10 release force recording

Claims (3)

[Claims] 1. To 100 parts by weight of polyamide resin, (1) melamine cyanurate 1 to 20 parts by weight (2) phosphorus compound 0.001 to 5 parts by weight (3) phenolic compound 0.001 to 1 parts by weight Part (4) Metal salt of aliphatic carboxylic acid having 22 or more carbon atoms
A flame-retardant polyamide resin composition containing 0.02 to 0.5 part by weight. 2. The phosphorus compound is a metal salt of hypophosphorous acid and / or the following formula (1); (In the formula, R ₁ is an alkyl group, and R ₂ and R ₃ are H
Or tris (alkyl-, which represents an alkyl group)
Aryl) phosphites and / or the following formula (2); (Wherein R ₁ and R ₂ are alkyl groups and may be the same or different) and / or phosphite ester of pentaerythritol and / or the following formula (3); Where R ₁ is alkylene and R ₂ and R ₃
Is an alkyl group, which may be the same or different) and is an alkylenebis (alkyl-aryl) alkyl phosphite represented by the formula 1. The flame-retardant polyamide resin composition according to claim 1. . 3. The flame-retardant polyamide resin composition according to claim 1, wherein the phenolic compound is a hindered phenol represented by the following formula (4). [Chemical 4] [In the formula, R ₁ and R ₂ are alkyl groups and may be the same or different. And A is -NH, -NHC _m H
_2m represents a group selected from the group consisting of _2m (m represents an integer from 2 to 8). ]