JP2018177874A - Polyamide resin composition and molded body obtained by molding the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition which can simultaneously satisfy high flowability and low metal corrosion while maintaining reflow heat resistance and flame retardancy.SOLUTION: A thermoplastic resin composition contains semi-aromatic polyamide (A) having a melting point of 280-320°C, aliphatic polyamide (B), phosphinic acid metal salt (C) of 5-39 mass% and a reinforcement material (D) of 5-60 mass%, where contents of the semi-aromatic polyamide (A) and the aliphatic polyamide (B) are 30-85 mass%, a mass ratio (A/B) of the semi-aromatic polyamide (A) to the aliphatic polyamide (B) is 90/10 to 40/60, a flow length in a mold with a thickness of 0.5 mm when a heater temperature is set at 320°C in injection molding is 100 mm or more, and a resin temperature when injected on such a condition that a flow length of 100 mm is obtained with the mold with the thickness of 0.5 mm at 320°C is 330°C or lower.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polyamide resin composition having flame retardancy.

  Polyamide is excellent in heat resistance and mechanical properties, and is used as a component material of many electric and electronic parts and parts around an automobile engine.

  Among these parts, polyamides constituting electric and electronic parts are required to have a high degree of flame retardancy. As a method of imparting flame retardancy to polyamide, a method of using a flame retardant is usually performed. In recent years, halogen-based flame retardants have been avoided from the rise of environmental awareness, and non-halogen-based flame retardants are generally used.

  Further, mounting of electric and electronic components is mainly performed by surface mounting, and in the reflow process, polyamides constituting the components are exposed to a high temperature of about 260 ° C. or so. Therefore, there are many cases where it is necessary to use a heat-resistant polyamide having a melting point of 270 ° C. or higher, which has reflow heat resistance, as the polyamide. As the heat-resistant polyamide having a melting point of 270 ° C. or higher, semiaromatic polyamide, polyamide 46 and the like are generally used.

  For example, Patent Document 1 discloses a semi-aromatic polyamide resin composition using a metal salt of phosphinate as a non-halogen flame retardant, and the flame retardant standard UL94 V for a 1/32 inch (0.79 mm) molded article It is disclosed to satisfy the -0 standard and to have reflow heat resistance and fluidity at a thickness of 0.5 mm.

However, electric and electronic parts tend to be miniaturized year by year, and thinner wall performance is required. In particular, with regard to flame retardancy and fluidity, generally, the thinner the wall, the lower the performance, and their improvement is strongly desired.
In addition, since heat-resistant polyamide has a high processing temperature due to its high melting point, heat-resistant polyamide resin compositions containing metal salts of phosphinic acids can be used for screws and dies of extruders and screws and dies of molding machines during melt processing. And other metal corrosion problems such as severe wear of metal parts.

  Thus, in designing a heat-resistant polyamide suitable for electric and electronic parts, it is very important to satisfy all the performances of reflow heat resistance, flame retardancy, fluidity, and low metal corrosiveness.

For these problems, Patent Document 2 discloses a material using a specific semiaromatic polyamide and a specific aliphatic polyamide in a weight ratio of 75/25 to 98/2. This material has a molding temperature of 340 ° C. and requires high temperature molding. Since the metal corrosiveness increases as the temperature increases, in this material, it is necessary to lower the forming temperature to reduce the metal corrosiveness, but if the forming temperature is lowered, the fluidity is significantly impaired. There is a problem that molding processing becomes difficult.
Further, Patent Document 3 discloses a material using a specific semiaromatic polyamide and a specific aliphatic polyamide in a weight ratio of 50/50 to 75/25. This material has improved fluidity as compared to the material disclosed in Patent Document 2, but metal corrosion has not been sufficiently reduced.

  It is important not only to lower the set temperature at the time of molding processing but also to lower the actual temperature of the resin composition, in order to reduce metal corrosion. Generally, the thinner the molding, the faster it needs to be molded. The resin composition tends to rise in temperature due to shear heat generation as it flows through the thin-walled part at high speed, and tends to become higher than the set temperature, so it is difficult to sufficiently reduce metal corrosion in forming thin-walled moldings. there were.

International Publication No. 2008/126381 Japanese Patent Application Publication No. 2014-517102 Japanese Patent Application Publication No. 2014-521765

  The present invention solves the above-mentioned problems in a flame retardant polyamide resin composition, and a polyamide capable of simultaneously satisfying high fluidity and low metal corrosion while maintaining reflow heat resistance and flame retardancy. It aims at providing a resin composition.

  As a result of intensive studies to solve the above problems, the present inventors contain semi-aromatic polyamide and aliphatic polyamide in a specific ratio, contain a specific amount of a specific flame retardant, and further inject Reflow heat resistance and flame retardancy by designing the thermoplastic resin composition so that it has high fluidity at processing temperature setting of 320 ° C in molding and resin temperature immediately after injection at 330 ° C setting becomes 330 ° C or less It has been found that the material has high flowability and low metal corrosion resistance, and reaches the present invention. That is, the gist of the present invention is as follows.

(1) Semi-aromatic polyamide (A), aliphatic polyamide (B), phosphinate metal salt (C) 5 to 39% by mass, reinforcing material (D) 5 to 60% by mass having a melting point of 280 to 320 ° C. Containing 30 to 85% by mass of the semiaromatic polyamide (A) and the aliphatic polyamide (B), and the mass ratio (A / B) of the semiaromatic polyamide (A) to the aliphatic polyamide (B) ) Is 90/10 to 40/60, and the flow length in a mold with a thickness of 0.5 mm at a heater temperature of 320 ° C. in injection molding is 100 mm or more, and the thickness 0.5 mm at a temperature of 320 ° C. A thermoplastic resin composition characterized by having a resin temperature of 330 ° C. or less when injected under injection conditions that can obtain a flow length of 100 mm with a metal mold.
(2) The polyamide resin composition according to (1), wherein the metal salt of phosphinic acid (C) is a compound represented by the following general formula (I) or (II).
(Wherein, R ¹ , R ² , R ⁴ and R ⁵ each independently represent a linear or branched alkyl group having 1 to 16 carbon atoms or a phenyl group. R ³ represents a linear or branched group. Represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an aryl alkylene group, or an alkyl arylene group, M represents a calcium ion, an aluminum ion, a magnesium ion or a zinc ion m Is 2 or 3. n, a, b are integers satisfying the formula 2 × b = n × a.)
(3) The polyamide resin composition according to (1) or (2), further comprising 0.01 to 5% by mass of a hydrazine compound having a hindered phenol structure.
(4) A molded article obtained by molding the polyamide resin composition according to any one of (1) to (3).

  According to the present invention, it is possible to provide a thermoplastic resin composition which is excellent in fluidity and low metal corrosion resistance in addition to excellent reflow heat resistance and flame resistance. Moreover, since the thermoplastic resin composition of the present invention is excellent in fluidity, it is possible to suppress an increase in temperature of the resin composition due to shear heat generation when molding a thin-walled molded product, and as a result, thin-wall molding Also in molding of the body, metal corrosion can be sufficiently reduced.

It is a figure which shows the apparatus for evaluating metal corrosiveness.

Hereinafter, the present invention will be described in detail.
The polyamide resin composition of the present invention contains a semiaromatic polyamide (A), an aliphatic polyamide (B), a metal phosphinate (C), and a reinforcing material (D).

The semiaromatic polyamide (A) constituting the polyamide resin composition of the present invention contains a dicarboxylic acid component and a diamine component as constituent components, contains an aromatic dicarboxylic acid in the dicarboxylic acid component, and is aliphatic in the diamine component It contains a diamine.
The dicarboxylic acid component constituting the semi-aromatic polyamide (A) preferably contains terephthalic acid (T), and the content of terephthalic acid is 95 mol% or more in the dicarboxylic acid component from the viewpoint of heat resistance. It is preferably present, and more preferably 100 mol%.
When the dicarboxylic acid component of the semi-aromatic polyamide (A) contains a dicarboxylic acid other than terephthalic acid, as the dicarboxylic acid other than terephthalic acid, an aromatic dicarboxylic acid component such as phthalic acid, isophthalic acid or naphthalene dicarboxylic acid, Aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc. Alicyclic acids such as cyclohexanedicarboxylic acid The formula dicarboxylic acid is mentioned. The amount of dicarboxylic acid other than terephthalic acid is preferably 5 mol% or less based on the total number of moles of the raw material monomers, and it is more preferably substantially free.

The diamine component in the semiaromatic polyamide (A) is preferably an aliphatic diamine having 8 to 12 carbon atoms from the viewpoint of heat resistance and processability. Examples of aliphatic diamines having 8 to 12 carbon atoms include 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine Among these, 1,10-decanediamine is preferable because of its high versatility. These may be used alone or in combination, but it is preferable to use them alone from the viewpoint of improving the mechanical properties.
When the diamine component of the semiaromatic polyamide (A) contains other diamines other than the aliphatic diamine component having 8 to 12 carbon atoms, examples of the other diamine include 1,2-ethanediamine, 1, 3 Propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15 -Aliphatic diamine components such as pentadecane diamine, alicyclic diamines such as cyclohexane diamine, and aromatic diamines such as xylylene diamine and phenylene diamine. The other diamine other than the aliphatic diamine component having 8 to 12 carbon atoms is preferably 5 mol% or less with respect to the total number of moles of the raw material monomer, and it is more preferable that the content not be substantially contained.

  The semi-aromatic polyamide (A) may contain, if necessary, lactams such as caprolactam and laurolactam, ω-aminocarboxylic acids such as aminocaproic acid and 11-aminoundecanoic acid.

  In the present invention, specific examples of the semiaromatic polyamide (A) include polyamide 4T, polyamide 8T, polyamide 9T, polyamide 10T, polyamide 11T, and polyamide 12T.

In the present invention, the semiaromatic polyamide (A) preferably has a monocarboxylic acid component as a component. A molded product obtained from a resin composition containing a semiaromatic polyamide (A) having aliphatic monocarboxylic acid as a constituent component and an aliphatic polyamide (B) has heat resistance in the surface layer portion of the molded product susceptible to heat. Since the highly semi-aromatic polyamide (A) tends to be the main component, blisters are less likely to occur in the reflow process.
The content of the monocarboxylic acid component is preferably 0.3 to 4.0 mol%, preferably 0.3 to 3.0 mol%, with respect to all the monomer components constituting the semi-aromatic polyamide (A). Some are more preferable, 0.3 to 2.5 mol% is more preferable, and 0.8 to 2.5 mol% is particularly preferable. By containing the monocarboxylic acid component within the above range, the molecular weight distribution at the time of polymerization can be reduced, the releasability at the time of molding can be improved, and the amount of gas generated at the time of molding can be suppressed. Be able to On the other hand, when the content of the monocarboxylic acid component exceeds the above range, mechanical properties and flame retardancy may be reduced. In the present invention, the content of the monocarboxylic acid means the ratio of the residue of the monocarboxylic acid in the semi-aromatic polyamide (A), that is, the monocarboxylic acid from which the terminal hydroxyl group has been eliminated.

  The semiaromatic polyamide (A) preferably contains, as a monocarboxylic acid component, a monocarboxylic acid having a molecular weight of 140 or more, and more preferably a monocarboxylic acid having a molecular weight of 170 or more. When the molecular weight of the monocarboxylic acid is 140 or more, the releasability is improved, the amount of gas generated can be suppressed at the temperature at the time of molding, and the molding flowability can also be improved.

  Examples of the monocarboxylic acid component include aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids. Among them, the amount of gas generated from polyamide-derived components is reduced to reduce mold stains and release. Aliphatic monocarboxylic acids are preferred because they can improve moldability.

Examples of aliphatic monocarboxylic acids having a molecular weight of 140 or more include caprylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid. Among them, stearic acid is preferable because of its high versatility.
Examples of alicyclic monocarboxylic acids having a molecular weight of 140 or more include 4-ethylcyclohexanecarboxylic acid, 4-hexylcyclohexanecarboxylic acid, and 4-laurylcyclohexanecarboxylic acid.
Examples of aromatic monocarboxylic acids having a molecular weight of 140 or more include 4-ethylbenzoic acid, 4-hexylbenzoic acid, 4-laurylbenzoic acid, 1-naphthoic acid, 2-naphthoic acid and derivatives thereof .

  The monocarboxylic acid components may be used alone or in combination. Further, a monocarboxylic acid having a molecular weight of 140 or more and a monocarboxylic acid having a molecular weight of less than 140 may be used in combination. In the present invention, the molecular weight of monocarboxylic acid refers to the molecular weight of monocarboxylic acid as a raw material.

  The melting point of the semi-aromatic polyamide (A) is required to be 280 to 320 ° C, preferably 290 to 320 ° C, and more preferably 300 to 320 ° C. When the melting point of the semiaromatic polyamide (A) is less than 280 ° C., the resin composition has a reduced reflow heat resistance. When the melting point of the semiaromatic polyamide (A) exceeds 320 ° C., the temperature of the resin composition at injection molding may exceed 330 ° C., and metal corrosion may increase.

  In the present invention, the semi-aromatic polyamide (A) preferably has a melt flow rate (MFR) of 1 to 200 g / 10 min, more preferably 10 to 150 g / 10 min, and 20 to 120 g / 10. More preferably, it is minutes. MFR can be used as an index of molding fluidity, and the higher the value of MFR, the higher the fluidity. When the MFR of the semiaromatic polyamide (A) exceeds 200 g / 10 min, the resulting resin composition may have reduced mechanical properties, and the MFR of the semiaromatic polyamide (A) is less than 1 g / 10 min If so, the flowability is extremely low, and melt processing may not be possible at a molding temperature of about 320 ° C.

  The higher the crystallinity of the semi-aromatic polyamide resin (A), the higher the crystallinity of the molded product obtained, and the heat resistance, the reflow heat resistance, the mechanical strength, and the low water absorption are further improved. It is preferable that the group polyamide (A) has the degree of crystallinity controlled in a specific range. In the present invention, the heat of crystal fusion (ΔH) measured using a differential scanning calorimeter (DSC) is used as an index of crystallinity, and ΔH of the semiaromatic polyamide resin (A) is 50 J / g or more. Is preferably 55 J / g or more. When ΔH is less than 50 J / g, the semi-aromatic polyamide resin (A) can not sufficiently enhance the crystallinity, and the resulting molded product may generate blisters in the reflow step.

  The semiaromatic polyamide (A) can be produced using a conventionally known method of heat polymerization or solution polymerization. The heat polymerization method is preferably used from the industrially advantageous point. The heat polymerization method is a method comprising a step (i) of obtaining a reaction product from a dicarboxylic acid component, a diamine component and a monocarboxylic acid component, and a step (ii) of polymerizing the obtained reaction product It can be mentioned.

  In the step (i), for example, the dicarboxylic acid powder and the monocarboxylic acid are mixed and heated in advance to a temperature not lower than the melting point of diamine and not higher than the melting point of dicarboxylic acid, and the dicarboxylic acid powder at this temperature and the monocarboxylic acid In addition, there is a method of adding a diamine substantially without containing water so as to maintain the state of powder of dicarboxylic acid. Alternatively, as another method, a suspension of molten diamine and solid dicarboxylic acid is stirred and mixed to obtain a mixture, and then at a temperature less than the melting point of the semiaromatic polyamide finally formed. And a reaction of forming a salt by the reaction of a dicarboxylic acid, a diamine and a monocarboxylic acid, and a reaction of forming a low polymer by polymerization of the formed salt to obtain a mixture of a salt and a low polymer. In this case, crushing may be carried out while the reaction is being carried out, or crushing may be carried out after being taken out once after the reaction. As the step (i), the former in which the control of the shape of the reaction product is easy is preferable.

  In step (ii), for example, the reaction product obtained in step (i) is subjected to solid phase polymerization at a temperature lower than the melting point of the semiaromatic polyamide to be finally produced, and is polymerized to a predetermined molecular weight And semiaromatic polyamides. The solid phase polymerization is preferably performed in a stream of inert gas such as nitrogen at a polymerization temperature of 180 to 270 ° C. and a reaction time of 0.5 to 10 hours.

  The reaction apparatus of step (i) and step (ii) is not particularly limited, and a known apparatus may be used. Step (i) and step (ii) may be performed in the same device or in different devices.

  In the production of the semi-aromatic polyamide (A), a polymerization catalyst may be used to enhance the efficiency of the polymerization. The polymerization catalyst includes, for example, phosphoric acid, phosphorous acid, hypophosphorous acid or salts thereof. In general, the addition amount of the polymerization catalyst is preferably 2 mol% or less based on all the monomers constituting the semi-aromatic polyamide (A).

  The aliphatic polyamide (B) constituting the polyamide resin composition of the present invention is a polyamide which does not contain an aromatic component in its main chain, and, for example, poly .epsilon.-capramide (polyamide 6), polytetramethylene adipamide ( Polyamide 46), polyhexamethylene adipamide (polyamide 66), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), porunde Examples thereof include canamide (polyamide 11), polydodecanamide (polyamide 12), and a polyamide copolymer containing at least two different polyamide components of these, or a mixture of these. Among them, polyamide 6 and polyamide 66 are preferable from the viewpoint of fluidity and economy.

  The relative viscosity of the aliphatic polyamide (B) is not particularly limited, and may be appropriately set according to the purpose. For example, in order to obtain a resin composition which can be easily molded, the aliphatic polyamide (B) preferably has a relative viscosity of 1.9 to 4.0, and 2.0 to 3.5. More preferable. If the relative viscosity of the aliphatic polyamide (B) is less than 1.9, depending on the molded product, the toughness may be insufficient, which may lead to a decrease in mechanical properties. In addition, when the relative viscosity of the aliphatic polyamide (B) exceeds 4.0, the resin composition becomes difficult to form and process, and the resulting molded article may have a poor appearance.

The total content of the semiaromatic polyamide (A) and the aliphatic polyamide (B) in the polyamide resin composition of the present invention needs to be 30 to 85% by mass, and is 35 to 80% by mass. Is preferable, and 40 to 75% by mass is more preferable. When the total content of the semiaromatic polyamide (A) and the aliphatic polyamide (B) is less than 30% by mass, the resin composition may have a decrease in fluidity, and when it exceeds 85% by mass, it is difficult The flammability may decrease.
The mass ratio (A / B) of the semiaromatic polyamide (A) to the aliphatic polyamide (B) needs to be 90/10 to 40/60, and is 85/15 to 45/55. Preferably, it is 80/20 to 48/52. When the proportion of the semiaromatic polyamide (A) exceeds 90% by mass, that is, the proportion of the aliphatic polyamide (B) is less than 10% by mass, the resin composition has a reduced fluidity, and it is at the time of injection molding The temperature may exceed 330 ° C. and metal corrosion may increase. On the other hand, when the proportion of the semiaromatic polyamide (A) is less than 40% by mass, that is, the proportion of the aliphatic polyamide (B) exceeds 60% by mass, the reflow heat resistance of the resin composition may decrease.

The polyamide resin composition of the present invention contains metal phosphinate (C).
The content of the metal salt of phosphinic acid (C) in the resin composition needs to be 5 to 39% by mass, preferably 8 to 25% by mass, and further preferably 15 to 25% by mass. preferable. When the content of the metal phosphinate (C) is less than 5% by mass, it becomes difficult to impart the required flame retardancy to the resin composition. On the other hand, when the content of the metal salt of phosphinic acid (C) exceeds 30% by mass, the resin composition is excellent in flame retardancy, but on the other hand, the metal corrosiveness increases and melt kneading may become difficult. Also, the resulting molded body may have insufficient mechanical properties.

  Examples of the metal phosphinate (C) of the present invention include metal phosphinates represented by the following general formula (I) and metal diphosphinates represented by the general formula (II).

In the formula, R ¹ , R ² , R ⁴ and R ⁵ are each independently required to be a linear or branched alkyl group having 1 to 16 carbon atoms or a phenyl group, and having 1 to 8 carbon atoms Alkyl group or phenyl group is preferable, and methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-pentyl group, n-octyl group, phenyl group Is more preferable, and an ethyl group is more preferable. R ¹ and R ² and R ⁴ and R ⁵ may form a ring with each other.
R ³ is required to be a linear or branched C 1 to C 10 alkylene group, a C ⁶ to C 10 arylene group, an aryl alkylene group, or an alkyl arylene group. Examples of the linear or branched alkylene group having 1 to 10 carbon atoms include methylene, ethylene, n-propylene, isopropylene, isopropylidene, n-butylene, tert-butylene and n- Examples include pentylene group, n-octylene group and n-dodecylene group. As a C6-C10 arylene group, a phenylene group and a naphthylene group are mentioned, for example. As an alkyl arylene group, a methyl phenylene group, an ethyl phenylene group, a tert- butyl phenylene group, a methyl naphthylene group, an ethyl napthylene group, a tert- butyl napthylene group is mentioned, for example. As an aryl alkylene group, a phenyl methylene group, phenyl ethylene group, phenyl propylene group, phenyl butylene group is mentioned, for example.
M represents a metal ion. Examples of the metal ion include calcium ion, aluminum ion, magnesium ion and zinc ion. Aluminum ion and zinc ion are preferable, and aluminum ion is more preferable.
m and n represent the valence of the metal ion. m is 2 or 3; a represents the number of metal ions, b represents the number of diphosphinate ions, and n, a and b are integers that satisfy the relational expression “2 × b = n × a”.

  Phosphinic acid metal salts and diphosphinic acid metal salts are prepared in aqueous solution using the corresponding phosphinic acids and diphosphinic acids and metal carbonates, metal hydroxides or metal oxides, respectively, and are usually present as monomers. Depending on the reaction conditions, they may be present in the form of polymeric phosphinates with a degree of condensation of 1 to 3.

  As specific examples of the phosphinate represented by the above general formula (I), for example, calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, ethyl methyl phosphine Magnesium acid, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, methyl-n-propyl phosphine Magnesium, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, methyl phenylphosphinate calcium Arm, magnesium methylphenyl phosphinate, aluminum methylphenyl phosphinate, methyl phenyl phosphinate, zinc, calcium diphenyl phosphinate, magnesium diphenyl phosphinate, aluminum diphenyl phosphinic acid, diphenyl phosphinic acid zinc. Among them, aluminum diethylphosphinate and zinc diethylphosphinate are preferable, and aluminum diethylphosphinate is more preferable, because they are excellent in the balance of flame retardancy and electrical characteristics.

  Moreover, as a diphosphinic acid used for manufacture of a diphosphinic acid salt, methane di (methyl phosphinic acid) and benzene 1, 4- di (methyl phosphinic acid) are mentioned, for example.

  Specific examples of the diphosphinic acid salt represented by the above general formula (II) include, for example, calcium methanedi (methylphosphinate), magnesium methanedi (methylphosphinate), aluminum methanedi (methylphosphinate), methanedi (methylphosphinic acid) ) Zinc, Benzene-1,4-di (methylphosphinate), Benzene-1,4-di (methylphosphinate) magnesium, Benzene-1,4-di (methylphosphinate) aluminum, Benzene-1,4 -Di (methylphosphinic acid) zinc is mentioned. Among these, aluminum methanedi (methylphosphinate) and zinc methanedi (methylphosphinate) are preferable because they are excellent in the flame retardancy and the balance of the electrical characteristics.

  Specific examples of the phosphinic acid metal salt (C) include "Exolit OP1230", "Exolit OP1240", "Exolit OP1312" and "Exolit OP1314" and "Exolit OP1400" manufactured by Clariant.

The polyamide resin composition of the present invention contains a reinforcing material (D).
As a reinforcement (D), a fibrous reinforcement is mentioned.
Examples of fibrous reinforcement include glass fiber, carbon fiber, boron fiber, asbestos fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, aramid fiber, polybenzoxazole fiber, kenaf fiber, bamboo fiber, hemp fiber, bagasse fiber And high strength polyethylene fibers, alumina fibers, silicon carbide fibers, potassium titanate fibers, brass fibers, stainless steel fibers, steel fibers, ceramic fibers and basalt fibers. Among them, glass fibers, carbon fibers, and aramid fibers are preferable because they are highly effective in improving mechanical properties, have heat resistance that can withstand heating temperatures during melt kneading with polyamide, and are easy to obtain. Specific trade names of glass fiber include, for example, “CS3G225S” manufactured by Nittobo Co., Ltd. and “T-781H” manufactured by Nippon Electric Glass Co., Ltd. Examples of specific trade names of carbon fiber include, for example, Toho Tenax Company-made "HTA-C6-NR" is mentioned. The fibrous reinforcing materials may be used alone or in combination.

  The fiber length and the fiber diameter of the fibrous reinforcing material are not particularly limited, but the fiber length is preferably 0.1 to 7 mm, and more preferably 0.5 to 6 mm. By setting the fiber length of the fibrous reinforcing material to 0.1 to 7 mm, the resin composition can be reinforced without adversely affecting moldability. The fiber diameter is preferably 3 to 20 μm, and more preferably 5 to 13 μm. By setting the fiber diameter to 3 to 20 μm, the resin composition can be efficiently reinforced without breakage at the time of melt-kneading. Examples of the cross-sectional shape include, for example, a circle, a rectangle, an ellipse, and other modified cross-sections. Among them, the circle is preferable.

  As the reinforcing material (D), in addition to the fibrous reinforcing material, a needle-like reinforcing material or a plate-like reinforcing material may be used. In particular, by using a fibrous reinforcing material in combination with a needle-like reinforcing material or a plate-like reinforcing material, it is possible to reduce the warpage of the molded body or to improve the drip resistance at the time of the flame retardancy test. As the needle-like reinforcing material, wollastonite, potassium titanate whisker, zinc oxide whisker, magnesium sulfate whisker and the like can be mentioned. The plate-like reinforcing material may, for example, be talc, mica or glass flakes.

  The content of the reinforcing material (D) in the resin composition is required to be 5 to 60% by mass, more preferably 10 to 50% by mass, in order to realize sufficient mechanical strength. It is more preferable that it is 20-40 mass%. When the content of the reinforcing material (D) is less than 5% by mass, the improvement effect of the mechanical properties may be small, and the flame retardance may be reduced. On the other hand, when the content of the reinforcing material (D) exceeds 60% by mass, the resin composition is saturated with the effect of improving mechanical properties, and further improvement effect can not be expected, and the fluidity is extremely high. It may be difficult to obtain a shaped body because of the decrease.

  The polyamide resin composition of the present invention may further contain a flame retardant auxiliary. Examples of the flame retardant auxiliary include nitrogen flame retardants, nitrogen-phosphorus flame retardants, and inorganic flame retardants.

  The polyamide resin composition of the present invention preferably contains a hydrazine compound having a hindered phenol structure. Hydrazine compounds having a hindered phenol structure have both a hindered phenol structure having an effect of capturing a peroxy radical and a hydrazine structure that chelates a metal ion. Specifically, a compound represented by the following formula (III) can be mentioned.

  By combining the phosphinic acid metal salt (C) with a hydrazine compound having a hindered phenol structure, the flame retardancy of the polyamide can be dramatically improved. Therefore, the compounding quantity of a phosphinic acid metal salt (C) can be reduced, and the metal corrosiveness which is a subject of the polyamide resin composition containing a phosphinic acid metal salt can be suppressed.

  As a specific commodity of the hydrazine type compound having a hindered phenol structure, for example, “CDA-10” manufactured by Adeka Co., Ltd., “IRGANOX MD 1024” manufactured by BFASF, etc. may be mentioned.

  The content of the hydrazine compound having a hindered phenol structure in the resin composition is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and 0.1 to 2 More preferably, it is mass%. If the content of the hydrazine-based compound having a hindered phenol structure is less than 0.01% by mass, the effect of improving the flame retardant efficiency can not be obtained, while if the content exceeds 5% by mass, the flame retardant efficiency is increased. Not only is no further improvement effect expected, but the resulting molded body may have insufficient mechanical strength.

  The polyamide resin composition of the present invention may further contain a flame retardant auxiliary. Examples of the flame retardant auxiliary include nitrogen flame retardants, nitrogen-phosphorus flame retardants, and inorganic flame retardants.

  Examples of nitrogen-based flame retardants include melamine-based compounds, cyanuric acid or salts of isocyanuric acid and melamine compounds, and the like. Specific examples of melamine compounds include melamine, melamine derivatives, compounds having a similar structure to melamine, condensates of melamine, etc. Specifically, melamine, ammelide, ammeline, formoguanamine, guanylmelamine, cyano Compounds having a triazine skeleton such as melamine, benzoguanamine, acetoguanamine, succino guanamine, melam, melem, meton, melon and the like, sulfates thereof, melamine resins and the like can be mentioned. The cyanuric acid or a salt of isocyanuric acid and a melamine compound is an equimolar reaction product of cyanuric acids or isocyanuric acids and a melamine compound.

As a nitrogen-phosphorus flame retardant, the adduct (melamine adduct) formed from melamine or its condensation product and a phosphorus compound, a phosphazene compound can be mentioned, for example.
Examples of the phosphorus compound constituting the melamine adduct include phosphoric acid, orthophosphoric acid, phosphonic acid, phosphinic acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, polyphosphoric acid and the like. Specific examples of melamine adducts include melamine phosphates, melamine pyrophosphates, dimelamine pyrophosphates, melamine polyphosphates, melem polyphosphates, melam polyphosphates, among which melamine polyphosphates are preferred. The number of phosphorus is preferably 2 or more, more preferably 10 or more.
Specific commercial products of phosphazene compounds include, for example, "Ravitor FP-100" manufactured by Fushimi Pharmaceutical Co., Ltd., "Ravitor FP-110", "SPS-100" manufactured by Otsuka Chemical Co., Ltd., and "SPB-100". .

  Examples of inorganic flame retardants include metal hydroxides such as magnesium hydroxide and calcium hydroxide, phosphates such as zinc borate and aluminum phosphate, phosphites such as aluminum phosphite, and calcium hypophosphite And hypophosphites such as calcium aluminate. These inorganic flame retardants may be blended for the purpose of improving flame retardancy and reducing metal corrosiveness.

  The polyamide resin composition of the present invention can be made further excellent in stability and moldability by containing a phosphorus-based antioxidant.

  The phosphorus-based antioxidant may be either an inorganic compound or an organic compound. Examples of phosphorus antioxidants include inorganic phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, sodium phosphite, calcium phosphite, magnesium phosphite, manganese phosphite, etc., tri Phenyl phosphite, trioctadecyl phosphite, tridecyl phosphite, torinylphenyl phosphite, diphenyl isodecyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite (" Adekastab PEP-36 "), bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (" Adecastab PEP-24G "), tris (2,4-di-tert-butylphenyl) phosphite, Distearyl pentaerythritol Phosphite ("Adecastab PEP-8"), Bis (nonylphenyl) pentaerythritol diphosphite ("Adecastab PEP-4C"), 1,1'-biphenyl-4,4'-diyl bis [phosphorous acid bis (2 , 4-Di-tert-butylphenyl)], tetrakis (2,4-di-tert-butylphenyl) 4,4′-biphenylene-di-phosphonite (“Fostanox P-EPQ”), tetra (tridecyl-4) Organic phosphorus compounds such as 4,4'-isopropylidene diphenyl diphosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite etc. Phosphorus-based antioxidants are used alone It may be used together.

  The phosphorus-based antioxidant is likely to be uniformly mixed with the metal phosphinate (C), and can prevent decomposition, thereby improving the flame retardancy. Further, the phosphorus-based antioxidant can prevent the decomposition and the molecular weight reduction of the semiaromatic polyamide (A) and the aliphatic polyamide (B), and can improve the operability, the moldability and the mechanical properties at the time of melt processing .

  The polyamide resin composition of the present invention may further contain other additives such as a stabilizer, a colorant, an antistatic agent, a carbonization inhibitor and the like, as necessary. Examples of the colorant include pigments such as titanium oxide, zinc oxide and carbon black, and dyes such as nigrosine. Examples of the stabilizer include hindered phenol-based antioxidants, sulfur-based antioxidants, light stabilizers, heat stabilizers made of copper compounds, and heat stabilizers made of alcohols. The carbonization inhibitor is an additive for improving the tracking resistance, and examples thereof include inorganic substances such as metal hydroxides and metal salts of boric acid, and the above-mentioned heat stabilizers.

  The method for producing the resin composition of the present invention is not particularly limited, but semi-aromatic polyamide (A), aliphatic polyamide (B), metal salt of phosphinate (C), reinforcing material (D), and if necessary The other additive etc. which are added are mixed, and the method of melt-kneading is preferable. Examples of the melt-kneading method include a method using a batch type kneader such as Brabender, a Banbury mixer, a Henschel mixer, a helical rotor, a roll, a single screw extruder, a twin screw extruder, and the like. The melt-kneading temperature is selected from the range where the semi-aromatic polyamide (A) and the aliphatic polyamide (B) melt and do not decompose. If the melt-kneading temperature is too high, not only the semi-aromatic polyamide (A) or aliphatic polyamide (B) decomposes, but also the metal phosphinate (C) may decompose, so the semi-aromatic polyamide It is preferable that they are (Tm-20 degreeC)-(Tm + 50 degreeC), if melting | fusing point of (A) is set to Tm.

  As a method of processing the polyamide resin composition of the present invention into various shapes, there are a method of extruding the molten mixture into strands and a pellet shape, a hot cut and an underwater cut of the molten mixture to form pellets, A method of extruding and cutting into a sheet shape, and a method of extruding and crushing into a block shape into a powder shape can be mentioned.

Examples of the molding method of the polyamide resin composition of the present invention include an injection molding method, an extrusion molding method, a blow molding method and a sinter molding method. Molding is preferred.
The injection molding machine is not particularly limited, and examples thereof include a screw in-line injection molding machine and a plunger injection molding machine. The polyamide resin composition heated and melted in the cylinder of the injection molding machine is measured shot by shot, injected in the molten state into the mold, cooled and solidified in a predetermined shape, and then molded from the mold as a molded body Taken out. The heater set temperature at the time of injection molding is preferably equal to or higher than the melting point (Tm) of the semiaromatic polyamide (A), but molding is preferably performed at 320 ° C. or less in order to suppress metal corrosion.
When the polyamide resin composition is heated and melted, it is preferable to use a polyamide resin composition pellet sufficiently dried. When the polyamide resin composition pellet contains a large amount of water, it may foam in the cylinder of the injection molding machine and it may be difficult to obtain an optimum molded body. The moisture content of the polyamide resin composition pellet used for injection molding is preferably less than 0.3 parts by mass and more preferably less than 0.1 parts by mass with respect to 100 parts by mass of the polyamide resin composition.

The polyamide resin composition of the present invention is excellent in reflow heat resistance and flame retardancy, has high fluidity, can suppress metal corrosion and can form thin-walled products, and can be used for automobile parts, electric and electronic parts, and miscellaneous goods. It can be used as a molding for a wide range of applications such as civil engineering and construction supplies.
Examples of automobile parts include thermostat covers, IGBT module members for inverters, insulator members, exhaust finishers, power device casings, ECU casings, ECU connectors, insulating materials for motors and coils, and covering materials for cables. Examples of electric and electronic parts include connectors, LED reflectors, switches, sensors, sockets, capacitors, jacks, fuse holders, relays, coil bobbins, breakers, electromagnetic switches, holders, plugs, and casings of electric devices such as portable personal computers. Parts, resistors, ICs, LED housings can be mentioned. Among them, the polyamide resin composition of the present invention can be suitably used for electric and electronic parts since it is particularly excellent in flame retardancy.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples.

1. Measurement Method Physical properties of the polyamide and the polyamide resin composition were measured by the following method.

(1) Melting point and heat of fusion Using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), the temperature is raised to 350 ° C. at a heating rate of 20 ° C./min, and then held at 350 ° C. for 5 minutes. The temperature is lowered to 25 ° C at 25 ° C / min and kept at 25 ° C for 5 minutes, then the top of the endothermic peak when the temperature is raised again at a heating rate of 20 ° C / min is taken as the melting point (Tm). did.

(2) Melt flow rate (MFR)
According to JIS K 7210, (melting point + 15 ° C), it measured at a load of 1.2 kgf.
MFR can be used as an index of molding fluidity, and the higher the value of MFR, the higher the fluidity.

(3) Liquidity (bar flow length)
A polyamide resin composition is set to a cylinder temperature of 320 ° C. and a mold temperature of 140 ° C. using an injection molding machine (ROBOSHOT S2000i manufactured by FANUC Co., Ltd.), clamping force 100 tons, injection pressure 150 MPa, injection speed 300 mm / A dedicated mold of one side one-point gate was attached to the end of the cylinder and molding was performed under the conditions of second and injection time of 5 seconds, and the bar flow flow length was measured. The dedicated mold has a shape capable of collecting an L-shaped compact having a thickness of 0.5 mm and a width of 20 mm, and has a gate at the upper center of the L-shape, and the flow length is 150 mm at maximum.
In the present invention, the bar flow flow length is preferably 100 mm or more.

(4) Reflow heat resistance The polyamide resin composition was injection molded using a injection molding machine (J35AD manufactured by Japan Steel Works, Ltd.) at a cylinder temperature of 320 ° C. and a mold temperature of 140 ° C. to obtain 20 mm × 20 mm × 0. A 5 mm test piece was produced. The test pieces obtained were subjected to moisture absorption treatment at 85 ° C. × 85% RH for 168 hours, and then heated at 150 ° C. for 1 minute in an infrared heating reflow furnace at a rate of 100 ° C./minute The temperature was raised to 260 ° C. and held for 10 seconds.
The case where there was no change in the appearance of the test piece was evaluated as ○, and the case where blisters occurred in the appearance or the case where the test piece melted was evaluated as x.

(5) Flame retardancy The polyamide resin composition was injection molded using a injection molding machine (J35AD manufactured by Japan Steel Works, Ltd.) at a cylinder temperature of 320 ° C. and a mold temperature of 140 ° C., 5 inches (127 mm) × A test piece of 1/2 inch (12.7 mm) x 1/127 inch (0.5 mm) was produced. Using the obtained test pieces, the flame retardancy was evaluated in accordance with the standards of UL94 (standard defined by Under Writers Laboratories Inc., USA) shown in Table 1. When the evaluation result did not reach V-2, it was regarded as "not V-2."
The shorter the total afterflame time, the better the flame retardancy.

(6) Metal corrosiveness As shown in FIG. 1, a die (D) is attached to a twin-screw kneading extruder (EX) (Ikegai Corporation PCM 30), and a metal plate (MP) (material used as steel material for ordinary extruders) SUS630, 20 × 10 mm, thickness 5 mm, weight 7.8 g) was attached to the upper and lower sides of the flow path (R) of the molten resin, a gap of 1 mm was provided, and the molten resin was in contact over 10 mm wide and 20 mm long . A total of 25 kg of the polyamide resin composition was extruded into the gap under the conditions of an extruder barrel temperature of 330 ° C. and a discharge of 7 kg / h. After extrusion, the metal plate (MP) was removed, and left in a furnace at 500 ° C. for 10 hours. After removing the adhered resin, the mass was measured, and metal corrosion was measured by mass change before and after extrusion. The greater the change in weight, the greater the metal corrosion. In the present invention, the weight change rate is preferably 0.40% or less.

(7) Resin composition temperature at molding The polyamide resin composition was set to a cylinder temperature of 320 ° C. and a mold temperature of 140 ° C. using an injection molding machine (ROBOSHOT S2000i manufactured by FANUC Co., Ltd.) and a clamping force of 100 tons. A mold for exclusive use of a one-sided one-point gate was attached to the end of the cylinder under the conditions of an injection speed pressure of 200 MPa and an injection time of 5 seconds, and molding was performed to measure the bar flow flow length. The dedicated mold has a shape capable of collecting an L-shaped compact having a thickness of 0.5 mm and a width of 20 mm, and has a gate at the upper center of the L-shape, and the flow length is 150 mm at maximum.
The molding was started under the condition of 10 mm / sec injection speed, and the molding was performed while increasing the injection speed by 10 mm / sec every shot, and the nozzle was backed under the injection speed condition where the bar flow length exceeded 100 mm. It injected in the state and measured the temperature of the resin composition which came out of the nozzle by the contact-type thermometer rapidly. In the present invention, it is preferable that the temperature of the resin composition is 330 ° C. or less, since the resin composition which is susceptible to shear heat generation at the time of injection increases the temperature and mold corrosion is likely to occur.

2. Raw Materials Raw materials used in Examples and Comparative Examples are shown below.

(1) Semi-aromatic polyamide (A)
・ Semi-aromatic polyamide (A-1)
4.70 kg of powdered terephthalic acid (TPA) as a dicarboxylic acid component, 0.32 kg of stearic acid (STA) as a monocarboxylic acid component, 9.3 g of sodium hypophosphite monohydrate as a polymerization catalyst, The reactor was placed in a ribbon blender type reactor and heated to 170 ° C. with stirring at a rotation speed of 30 rpm under a nitrogen blanket. Thereafter, while maintaining the temperature at 170 ° C. and the rotation speed at 30 rpm, using a liquid feeder, 2.98 kg of 1,10-decanediamine (DDA) heated to 100 ° C. as a diamine component, 2 The reaction product was obtained by continuous addition (continuous liquid injection method) over 5 hours. The molar ratio of the raw material monomers is TPA: DDA: STA = 48.5: 49.6: 1.9 (the equivalent ratio of the functional groups of the raw material monomers is TPA: DDA: STA = 49.0: 50.0). : 1.0).
Subsequently, the obtained reaction product was polymerized by heating in the same reactor under a nitrogen stream at 250 ° C. and a rotation number of 30 rpm for 8 hours to produce a polyamide powder.
Thereafter, the obtained polyamide powder is formed into strands using a twin-screw kneader, and the strands are passed through a water bath to cool and solidify, which is cut with a pelletizer to obtain semiaromatic polyamide (A-1) pellets. The

・ Semi-aromatic polyamide (A-2) to (A-8)
Semiaromatic polyamides (A-2) to (A-8) were obtained in the same manner as the semiaromatic polyamide (A-1) except that the resin composition was changed as shown in Table 1.

  The resin compositions and the characteristic values of the above semiaromatic polyamides (A-1) to (A-8) are shown in Table 2.

(2) Aliphatic polyamide (B)
-Polyamide 66 (Reona 1200 manufactured by Asahi Kasei Chemicals Co., Ltd.), relative viscosity 2.45
(3) Phosphinic acid metal salt (C)
-Diethylphosphinate aluminum (manufactured by Clariant Exolit OP 1230)
(4) Inorganic Reinforcement (D)
D-1: Glass fiber (Asahi Fiber Glass Co., Ltd., 03JAFT692), average fiber diameter 10 μm, average fiber length 3 mm
・ D-2: Talc (Micro Ace K-1 manufactured by Nippon Talc Co., Ltd.), average particle diameter 8 μm

Example 1
35 parts by mass of semi-aromatic polyamide (A-1), 15 parts by mass of aliphatic polyamide (B), and 20 parts by mass of metal phosphinate (C) are preblended, and a loss-in-weight type continuous quantitative supply device (manufactured by Kubota Corporation) Measure using CE-W-1 type), supply to main feed port of twin screw extruder TEM26SS type (TEM26SS type made by Toshiba Machine Co., Ltd.) with screw diameter 26 mm, L / D 50, and melt kneading The On the way, 30 parts by mass of the reinforcing material (D-1) was supplied from the side feeder and further kneading was performed. After being drawn from the die in the shape of a strand, it was cooled and solidified through a water bath, and it was cut with a pelletizer to obtain polyamide resin composition pellets. The barrel temperature setting of the extruder was (melting point −5 to + 15 ° C.), screw rotation speed 250 rpm, and discharge amount 25 kg / h.

Examples 2 to 17 and Comparative Examples 1 to 5, 7 and 8
An operation was performed in the same manner as in Example 1 except that the composition of the polyamide resin composition was changed as shown in Table 3, to obtain polyamide resin composition pellets.

Comparative example 6
An attempt was made to obtain polyamide resin composition pellets by performing the same operation as in Example 1 except that the composition of the polyamide resin composition was changed as shown in Table 3, but the content of the reinforcing material was too large. It was not possible to obtain pellets of the polyamide resin composition.

  Various evaluation tests were conducted using the obtained polyamide resin composition pellets. The results are shown in Table 3.

Since the resin compositions of Examples 1 to 17 satisfy the requirements of the present invention, the flowability, the reflow heat resistance, the flame retardancy, and the low metal corrosiveness were all good results.
The resin composition of Comparative Example 1 was too low in the content ratio of the aliphatic polyamide and low in fluidity, and the temperature at the time of molding exceeded 330 ° C., so that the metal corrosion was large.
The resin composition of Comparative Example 2 was poor in reflow heat resistance because the content ratio of the aliphatic polyamide was too large.
The resin composition of Comparative Example 3 was inferior in flame retardancy because the content of the flame retardant was too small.
The resin composition of Comparative Example 4 had a large content of the flame retardant, and was therefore high in metal corrosion.
The resin composition of Comparative Example 5 was inferior in flame retardance because it did not contain a reinforcing material.
In the resin composition of Comparative Example 7, the melting point of the semi-aromatic polyamide is high, and the temperature at the time of molding exceeds 330 ° C., so that the metal corrosiveness is large.
The resin composition of Comparative Example 8 was inferior in reflow heat resistance because the melting point of the semiaromatic polyamide was too low.

EX: Twin-screw kneading extruder D: Dice MP: Metal plate R: Flow path of molten resin

Claims (4)

  Containing semi-aromatic polyamide (A) having melting point of 280 to 320 ° C., aliphatic polyamide (B), 5 to 39% by mass of metal phosphinate (C) and 5 to 60% by mass of reinforcing material (D), The content of the semiaromatic polyamide (A) and the aliphatic polyamide (B) is 30 to 85% by mass, and the mass ratio (A / B) of the semiaromatic polyamide (A) to the aliphatic polyamide (B) is It is 90/10 to 40/60, and the flow length in the mold of 0.5 mm in thickness at the heater temperature setting of 320 ° C in injection molding is 100 mm or more, and the mold of 0.5 mm in thickness at the setting of 320 ° C. A thermoplastic resin composition characterized by having a resin temperature of 330 ° C. or less when injected under the injection conditions which give a flow length of 100 mm. The polyamide resin composition according to claim 1, wherein the metal salt of phosphinic acid (C) is a compound represented by the following general formula (I) or (II).
(Wherein, R ¹ , R ² , R ⁴ and R ⁵ each independently represent a linear or branched alkyl group having 1 to 16 carbon atoms or a phenyl group. R ³ represents a linear or branched group. Represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an aryl alkylene group, or an alkyl arylene group, M represents a calcium ion, an aluminum ion, a magnesium ion or a zinc ion m Is 2 or 3. n, a, b are integers satisfying the formula 2 × b = n × a.)   The polyamide resin composition according to claim 1 or 2, further comprising 0.01 to 5% by mass of a hydrazine compound having a hindered phenol structure.   The molded object characterized by shape | molding the polyamide resin composition in any one of Claims 1-3.