JP2013199570A - Polyamide resin composition and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition that is excellent in solder heat resistance and gives a molded product having excellent reflectance before and after aging.SOLUTION: A polyamide resin composition comprises: (A) 100 pts.wt. of a polyamide resin comprising a diamine unit that consists of paraxylylenediamine and a dicarboxylic acid unit that contains 70 mol% or more of a 6-18C linear aliphatic dicarboxylic acid; (B) 15-100 pts.wt. of at least one selected from an inorganic filler and a reinforcing material; and 10-100 pts.wt. of a white pigment. The polyamide resin composition further contains an antioxidant, an alkali metal hydroxide, and an alkaline earth hydroxide.

Description

  The present invention relates to a polyamide resin composition and a molded article using the same.

In recent years, new light sources such as light-emitting diodes (LEDs) and organic ELs have been increasing in demand as lighting, display elements and the like by taking advantage of low power and long life. In particular, LEDs are used in various applications such as mobile communication devices such as mobile phones, displays, automobile console panels, traffic lights, and other household appliances. Such electrical and electronic equipment products are increasingly becoming lighter, thinner, and smaller due to demands for design and portability.
Surface mounting technology (SMT) has become widespread as a key technology for realizing such miniaturization, and is used in many electrical and electronic equipment products. As a result, the mounting density of the electronic substrate has been dramatically improved, and a light, thin, and small size that has not been realized in the past has been achieved.

  When SMT is applied, in order to heat and solder the entire component mounted on the electronic substrate, the material can only be used if it can withstand the soldering temperature (230 to 240 ° C.). A polyamide resin composition is known as a material that can be used for such applications (for example, Patent Document 1).

Japanese Patent Laid-Open No. 2004-075994

The LED is no exception, and heat resistance to withstand SMT is required. The LED is generally composed of a semiconductor part that emits light, a lead wire, a reflector that also serves as a housing, and a transparent sealing agent that seals the semiconductor. Of these, the reflector part has been commercialized with various materials such as ceramics and heat-resistant plastics, but ceramics are more productive, while heat-resistant plastics are used in the injection molding process, the thermosetting process of the sealant, and the actual usage environment. In addition, a decrease in light reflectance due to discoloration is a problem.
The present invention is to solve such a conventional problem, and to provide a polyamide resin composition that has a heat resistance that can withstand SMT and that provides a molded article having excellent reflectance.

  Under such circumstances, as a result of intensive studies by the inventor of the present application, a polyamide comprising a diamine unit comprising paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms. The present inventors have found that the above problems can be solved by blending a specific amount of at least one selected from inorganic fillers and reinforcing materials and a white pigment into the resin, and have completed the present invention.

Specifically, the above problem has been solved by the following means <1>, preferably <2> to <11>.
<1> (A) 100 parts by weight of a polyamide resin composed of a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
(D) A polyamide resin composition containing 0.1 to 15 parts by weight of an antioxidant.
<2> (A) 100 parts by weight of a polyamide resin composed of a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
A polyamide resin composition comprising 0.1 to 20 parts by weight of at least one selected from (E) alkali metal hydroxides and (F) alkaline earth metal hydroxides.
<3> (A) 100 parts by weight of a polyamide resin composed of a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
(D) 0.1 to 15 parts by weight of an antioxidant and (E) at least one selected from 0.1 to 20 parts by weight selected from alkali metal hydroxides and (F) alkaline earth metal hydroxides Polyamide resin composition.
<4> (B) The inorganic filler and reinforcing material include at least one selected from glass fiber, wollastonite, calcium carbonate, talc and mica, according to any one of <1> to <3>. Polyamide resin composition.
<5> (C) The polyamide resin according to any one of <1> to <4>, wherein the white pigment includes at least one selected from titanium oxide, zinc oxide, zinc sulfide, barium sulfide, and potassium titanate. Composition.
<6> (D) The antioxidant is at least one selected from phenolic antioxidants, phosphorus antioxidants, aromatic amine antioxidants, sulfur antioxidants, and imidazole antioxidants. The polyamide resin composition according to any one of <1> and <3> to <5>.
<7> (C) The polyamide resin composition according to any one of <1> to <6>, wherein the white pigment is titanium oxide surface-treated with an inorganic material and / or an organic material.
<8> (D) The antioxidant is at least one selected from a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and an imidazole-based antioxidant, <1>, <1 The polyamide resin composition according to any one of 3> to <5> and <7>.
<9> (D) The polyamide resin composition according to any one of <1> and <3> to <8>, wherein at least one of the antioxidants is a phenolic antioxidant.
<10> (D) at least one of the antioxidants is N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), <1> and The polyamide resin composition according to any one of <3> to <8>.
<11> (A) The polyamide resin composition according to any one of <1> to <10>, wherein the polyamide resin has a melting point of 280 ° C. or higher.
<12> (A) The polyamide resin composition according to any one of <1> to <11>, wherein the dicarboxylic acid unit of the polyamide resin is sebacic acid.
<13> A molded product obtained by molding the polyamide resin composition according to any one of <1> to <12>.
<14> The molded article according to <13>, which is for a light emitting diode.

  According to the present invention, it has become possible to provide a polyamide resin composition that provides a molded article having excellent solder heat resistance and excellent reflectance before and after aging.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. Unless otherwise specified, the reflectance in the present invention refers to the reflectance at a wavelength of 450 nm.

The polyamide resin composition of the present invention comprises (A) 100 parts by weight of a polyamide resin consisting of a diamine unit consisting of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms. (B) at least one selected from 15 to 100 parts by weight selected from inorganic fillers and reinforcing materials, and (C) 10 to 100 parts by weight of a white pigment, and (A) 100 parts by weight of polyamide resin, (D) 0.1 to 15 parts by weight of an antioxidant and / or (E) at least one selected from alkali metal hydroxides and (F) alkaline earth metal hydroxides from 0.1 to 20 It is preferable that a weight part is included.
Hereinafter, these components will be described in detail.

<(A) Polyamide resin>
The polyamide resin used in the present invention is characterized by comprising a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms. (A) The polyamide resin may be only one type or two or more types.

  (A) The raw material dicarboxylic acid component used for the polyamide resin contains 70 to 6 mol% of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms, more preferably 80 mol% or more, and 90 mol% or more. Particularly preferred is 100 mol%. The polyamide resin obtained by adjusting the straight chain aliphatic dicarboxylic acid having 6 to 18 carbon atoms to 70 mol% or more exhibits fluidity at the time of melt processing, high crystallinity, low water absorption, heat resistance, chemical resistance, It can be suitably used for various applications as a polyamide resin excellent in molding processability and dimensional stability. When the concentration of the straight-chain aliphatic dicarboxylic acid having 6 to 18 carbon atoms in the raw material dicarboxylic acid component is less than 70 mol%, the heat resistance, chemical resistance and molding processability are deteriorated.

  Examples of the linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, Examples include hexadecanedioic acid. Among them, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid are preferable, sebacic acid and azelaic acid are more preferable, and sebacic acid is particularly preferable. If an aliphatic dicarboxylic acid having 5 or less carbon atoms is used in place of these, the melting point and boiling point of the dicarboxylic acid are low, so that the reaction molar ratio of the diamine and the dicarboxylic acid collapses during the polycondensation reaction. This is not preferable because the mechanical properties and thermal stability of the resulting polyamide resin are lowered. Further, when an aliphatic dicarboxylic acid having 19 or more carbon atoms is used, a polyamide resin having stable properties can be obtained, but this is not preferable because the melting point is greatly lowered and heat resistance cannot be obtained.

  As raw material dicarboxylic acids other than straight chain aliphatic dicarboxylic acids having 6 to 18 carbon atoms, malonic acid, succinic acid, 2-methyladipic acid, trimethyladipic acid, 2,2-dimethylglutaric acid, 2,4-dimethylglutaric acid 3,3-dimethylglutaric acid, 3,3-diethylsuccinic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, 2, Examples thereof include, but are not limited to, 6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, or a mixture thereof.

  The (A) polyamide resin used in the present invention is a fat such as ε-caprolactam or laurolactam, aminocaproic acid, aminoundecanoic acid or the like as long as the effects of the present invention are not impaired, in addition to the diamine component and dicarboxylic acid component. Group aminocarboxylic acids can also be used as copolymerization components. However, it is preferable that these components are 3 mol% or less of the whole.

The (A) polyamide resin used in the present invention preferably has a melting point of 280 ° C. or higher, more preferably 280 to 320 ° C. By setting it as such a range, it exists in the tendency for heat resistance to improve and also the reflectance after heat processing to improve.
The melting point is determined by using a differential scanning calorimeter and heating the sample to a temperature above the expected melting point at a rate of 20 ° C. per minute, and then lowering the sample at a rate of 10 ° C. per minute. The temperature can be measured by cooling to 20 ° C., leaving it for about 1 minute, and then heating again at a rate of 20 ° C. per minute.
The number average molecular weight of the (A) polyamide resin used in the present invention is preferably 10,000 to 50,000, and more preferably 14,000 to 30,000.

  The description of paragraph numbers 0020 to 0030 of JP2011-057931A can be referred to for the synthesis method and the like of the (A) polyamide resin used in the present invention, and the content of the publication is incorporated in the present specification.

  The blending amount of the (A) polyamide resin in the polyamide resin composition of the present invention is preferably 50 to 90% by weight, and more preferably 60 to 80% by weight.

<(B) Inorganic filler and reinforcing material>
The polyamide resin composition of the present invention contains (B) at least one selected from inorganic fillers and reinforcing materials. That is, the inorganic filler and the reinforcing material may be only one type or two or more types.
The blending amount of (B) inorganic filler and reinforcing material in the polyamide resin composition of the present invention is 15 to 100 parts by weight, preferably 15 to 80 parts, based on 100 parts by weight of (A) polyamide resin. Parts by weight, more preferably 15 to 50 parts by weight, still more preferably 18 to 30 parts by weight. If the blending amount of the inorganic filler is less than 15 parts by weight, the reinforcing effect is insufficient, and if it exceeds 100 parts by weight, the reflectance is inferior.
(B) The inorganic filler and the reinforcing material are preferably at least one selected from glass fiber, wollastonite, calcium carbonate, talc and mica, more preferably glass fiber and talc, and still more preferably glass fiber. .

  The glass fiber used by this invention consists of glass compositions, such as A glass, C glass, E glass, and S glass, and is especially preferable at the point which E glass (non-alkali glass) does not have a bad influence on a polycarbonate. In addition to a general perfect circle shape, the cross-sectional shape may be various irregular cross-sectional shapes typified by superimposing circular fibers in parallel. Such glass fibers have an average fiber diameter of 1 to 25 μm, preferably 5 to 17 μm. As such glass fiber, “glass roving” continuously wound, “chopped strand” cut to a length of 1 to 10 mm, and “milled fiber” ground to a length of about 10 to 500 μm can be used. It can also be used together. Glass fibers are commercially available from Asahi Fiber Glass Co., Ltd. under the trade names of “Glasslon Chopped Strand” and “Glasslon Milled Fiber” and are readily available. Further, the glass beads are spherical ones having an outer diameter of 10 to 100 μm, and are, for example, commercially available from Toshiba Barotini under the trade name “EGB731” and are easily available. The glass flake is a scale-like one having a thickness of 1 to 20 μm and a side length of 0.05 to 1.0 mm. For example, it is commercially available from Nippon Sheet Glass Co., Ltd. under the trade name “Fureka”. Is available. Further, these glass-based fillers are subjected to surface treatment such as silane treatment, epoxy treatment, urethane treatment, oxidation treatment, etc. in order to increase the affinity with the resin as long as the properties of the composition of the present invention are not impaired. May be.

<(C) White pigment>
The polyamide resin composition of the present invention contains at least one (C) white pigment. That is, only one type of white pigment may be used, or two or more types may be used.
The total amount of (C) white pigment in the polyamide resin composition of the present invention is 10 to 100 parts by weight, preferably 15 to 70 parts by weight, based on 100 parts by weight of (A) polyamide resin. Preferably it is 15-60 weight part, Most preferably, it is 18-35 weight part. When the amount of the white pigment is less than 10 parts by weight, the reflectance after the heat treatment is inferior.
The white pigment is preferably at least one selected from titanium oxide, zinc oxide, zinc sulfide, barium sulfide and potassium titanate, more preferably titanium oxide, zinc sulfide and potassium titanate, and even more preferably titanium oxide. .

As titanium oxide, it is preferable to use titanium oxide containing 80% by weight or more of titanium oxide from the viewpoint of whiteness and hiding properties among those commercially available.
Examples of the titanium oxide used in the present invention include titanium monoxide (TiO), titanium trioxide (Ti ₂ O ₃ ), titanium dioxide (TiO ₂ ), and any of these may be used. Titanium dioxide is preferred. Moreover, as titanium oxide, what has a rutile type crystal structure is normally used.

  The average particle size of titanium oxide is preferably in the range of 0.1 to 0.5 μm, more preferably in the range of 0.15 to 0.4 μm, and in the range of 0.2 to 0.3 μm. More preferably, it is within. By setting the average particle diameter of titanium oxide in such a range and the blending amount in the above range, a polyamide resin composition giving a molded product having high whiteness and high reflectance can be obtained.

As the titanium oxide, a surface-treated one may be used. As the surface treatment agent, inorganic materials and / or organic materials are preferable. Specific examples include metal oxides such as silica, alumina, and zinc oxide; organic materials such as silane coupling agents, titanium coupling agents, organic acids, polyols, and silicones.
Moreover, what is marketed can be used as a titanium oxide. Furthermore, it is also possible to use a material obtained by pulverizing a lump-shaped material or a material having a large average particle size, and classifying the material with a sieve or the like as necessary to obtain the above-mentioned average particle size.

<Other ingredients>
The polyamide resin composition of the present invention preferably further contains at least one selected from (D) an antioxidant, (E) an alkali metal hydroxide and (F) an alkaline earth metal hydroxide. That is, it may contain only (D) an antioxidant, (E) an alkali metal hydroxide, and (F) an alkaline earth metal hydroxide, or (D) an antioxidant and (E). As exemplified by both alkali metal hydroxides, (D) antioxidants and (F) alkaline earth metal hydroxides, etc. (D) antioxidants, (E) alkali metal hydroxides And (F) any two or more of alkaline earth metal hydroxides may be included. Naturally, the aspect of (D) including two or more kinds of antioxidants is also included in the present invention.

<(D) Antioxidant>
The polyamide resin composition of the present invention preferably contains at least one (D) antioxidant. That is, (D) two or more kinds of antioxidants may be included.
The total amount of the (D) antioxidant in the polyamide resin composition of the present invention is preferably 0.1 to 15 parts by weight, more preferably 0.1 to 100 parts by weight of the (A) polyamide resin. 1 to 10 parts by weight, more preferably 0.3 to 8 parts by weight, and particularly preferably 0.3 to 5 parts by weight.

  The antioxidant is preferably at least one selected from phenolic antioxidants, phosphorus antioxidants, aromatic amine antioxidants, sulfur antioxidants and imidazole antioxidants, and phenolic antioxidants. At least one selected from an agent, a phosphorus-based antioxidant, a sulfur-based antioxidant, and an imidazole-based antioxidant is more preferable, and at least a phenol-based antioxidant is more preferably included. When using 2 or more types together, the combination of a phenolic antioxidant and another antioxidant is preferable, and the combination of a phenolic antioxidant and a phosphorus antioxidant or sulfur type antioxidant is more preferable.

  Specific examples of the phenolic antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl). -4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexane-1,6-diylbis [3- (3 , 5-di-tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphoate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl- a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3 -(5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexa Methylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3 , 5-Triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine- 2-Irua Roh) phenol, and the like. These may be used alone or in combination of two or more.

  Examples of phosphorus antioxidants include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, tris ( Tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl tetra (tridecyl) pentaerythritol tetraphos Phyto, hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butyl Phenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidene diphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, dilaurylpentaerythritol diphosphite Phosphite, distearyl pentaerythritol diphosphite, tris (4-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylene phosphonite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t -Butyl-4 Methylphenyl) pentaerythritol diphosphite, 2,2′-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, ethyl diethylphosphonoacetate, methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, butoxy Ethyl acid phosphate, Octyl acid phosphate, Decyl acid phosphate, Lauryl acid phosphate, Stearyl acid phosphate, Oleyl acid phosphate, Behenyl acid phosphate, Phenyl acid phosphate, Nonyl phenyl acid phosphate, Cyclohexyl acid phosphate acid, Polyethylene acid phosphate Phosphate, bisphe Lumpur A acid phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, dilauryl phosphate, distearyl phosphate, diphenyl phosphate, bis-nonylphenyl phosphate, hexamethylphosphoric triamide, and the like. These may be used alone or in combination of two or more.

  Specific examples of the aromatic amine antioxidant include phenylnaphthylamine, 4,4′-dimethoxydiphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, and 4-isopropoxydiphenylamine. . These may be used alone or in combination of two or more.

  Examples of the sulfur-based antioxidant include didodecyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, dioctadecyl-3,3′-thiodipropionate, and ditridecyl-3. , 3'-thiodipropionate, pentaerythrityltetrakis (3-dodecylthiopropionate), pentaerythrityltetrakis (3-tetodecylthiopropionate), pentaerythrityltetrakis (3-tridecylthiopropionate) Nate) and the like. These may be used alone or in combination of two or more.

  Examples of the imidazole antioxidant include 2-mercaptobenzimidazole, zinc salt of 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, and the like. These may be used alone or in combination of two or more.

<(E) Alkali metal hydroxide, (F) Alkaline earth metal hydroxide>
The polyamide resin composition of the present invention preferably contains at least one of (E) alkali metal hydroxide and (F) alkaline earth metal hydroxide. That is, (E) alkali metal hydroxide and (F) alkaline earth metal may each contain two or more kinds.
(E) Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. (F) Examples of the alkaline earth metal hydroxide include magnesium hydroxide and calcium hydroxide.

As the alkali metal hydroxide and alkaline earth metal hydroxide, those subjected to surface treatment to improve the adhesion and dispersibility with the (A) polyamide resin may be used. Examples of the surface treatment agent include silane coupling agents such as aminosilane and epoxysilane, titanium coupling agents, organic substances such as organic acids, polyols, and silicones.
The average particle size of the alkali metal hydroxide and alkaline earth metal hydroxide is preferably 0.05 to 10 μm, and more preferably 0.1 to 5 μm.
The total amount of (E) alkali metal hydroxide and (F) alkaline earth metal in the polyamide resin composition of the present invention is 0.1 to 15 parts by weight per 100 parts by weight of (A) polyamide resin. The amount is preferably 0.1 to 12 parts by weight, and more preferably 0.3 to 10 parts by weight.

The polyamide resin composition of the present invention may further contain various additives as long as the effects of the present invention are not impaired. Examples of such additives include mold release agents, ultraviolet absorbers, polymer light stabilizers (HALS), flame retardants other than those mentioned above, dyes and pigments, fluorescent whitening agents, anti-dripping agents, antistatic agents, and antifogging agents. , Lubricants, antiblocking agents, fluidity improvers, plasticizers, dispersants, antibacterial agents and the like.
Moreover, these components may use only 1 type and may use 2 or more types together.

<Release agent>
The polyamide resin composition of the present invention may contain a release agent. Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane silicone oils, and the like.
Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acid. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipine Examples include acids and azelaic acid.

  As aliphatic carboxylic acid in ester of aliphatic carboxylic acid and alcohol, the same thing as the said aliphatic carboxylic acid can be used, for example. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic or alicyclic saturated monohydric alcohol or aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferable.

  Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. Is mentioned.

  Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate Examples thereof include rate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomer having 3 to 12 carbon atoms. Here, the aliphatic hydrocarbon includes alicyclic hydrocarbons. The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.
Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable.

  The content of the release agent is preferably 0.001 to 2 parts by weight, more preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the polyamide resin. When the content of the release agent is less than the lower limit of the range, the effect of releasability may not be sufficient, and when the content of the release agent exceeds the upper limit of the range, hydrolysis resistance And mold contamination during injection molding may occur.

  The polyamide resin composition of the present invention may be blended with a thermoplastic resin such as a polyamide resin other than the (A) polyamide resin or a polyester resin within a range not impairing the effects of the present invention.

The following aspects are mentioned as a preferable aspect of the polyamide resin composition of this invention.
(1) The aspect containing a polyamide resin, glass fiber, titanium oxide, and antioxidant.
(2) The aspect containing a polyamide resin, glass fiber, titanium oxide, antioxidant, and a mold release agent.
(3) In the above (1) or (2), the polyamide resin is a polyamide resin composed of paraxylylenediamine and sebacic acid.
(4) The aspect in which the titanium oxide is titanium dioxide in any one of the above (1) to (3).
(5) In any one of the above (1) to (4), the antioxidant is a phenolic antioxidant (in particular, N, N′-hexamethylenebis (3,5-di-t-butyl-4- The hydroxy-hydrocinnamamide)).
(6) In any one of the above (1) to (4), the antioxidant is a combination of a phenolic antioxidant and a phosphorus antioxidant.
(7) In any one of the above (1) to (4), the antioxidant is a combination of a phenol-based antioxidant and a sulfur-based antioxidant.
(8) The aspect containing magnesium hydroxide in any one of said (1)-(7).
(9) The aspect containing calcium hydroxide in any one of the above (1) to (7).

  The polyamide resin composition of this invention can be prepared by mix | blending each above-described component according to a well-known method. For example, a method of adding each component during the polycondensation reaction of the polyamide resin, a method of dry blending the polyamide resin and other components, a method of melt-kneading each component using an extruder, and the like can be mentioned. Among these, the method of melting and kneading each component using an extruder is advantageous because the operation is easy and a uniform composition can be obtained. The extruder used at this time is preferably a twin-screw type, and the melt kneading temperature is preferably in the range of from 5 ° C. to 350 ° C. higher than the melting point of polyamide.

The polyamide resin composition of the present invention is generally a thermoplastic resin composition such as injection molding, extrusion molding, press molding, blow molding, calendar molding, casting molding, etc., depending on the type, application, shape, etc. of the target molded product. Depending on the molding method used for the product, various molded products can be obtained. A molding method combining the above molding methods can also be employed. In particular, injection molding is preferable in terms of ease of molding, mass productivity, and cost.
Moreover, the polyamide resin composition of the present invention and another polymer can be composite-molded. Furthermore, the polyamide resin composition of the present invention can be combined with a metal molded body or fabric.

Molded articles obtained from the polyamide resin composition of the present invention include, for example, electronic parts such as connectors, switches, relays and printed wiring boards, reflecting mirrors such as lamp reflectors, sliding parts such as gears and cams, air intakes, and the like. It can be used for various parts such as automobile parts such as manifolds, water-borne parts such as sinks, various decorative parts, or films, sheets, and fibers.
The polyamide resin composition of the present invention gives a molded article having high whiteness and excellent reflectance, although it depends on the molding method. The whiteness (Hunter type) of the molded product obtained from the polyamide resin composition of the present invention is usually 92 or more, preferably 94 or more. Moreover, the molded product obtained from the polyamide resin composition of the present invention is excellent in heat resistance and light stability in an actual use environment. Therefore, the molded product obtained from the polyamide resin composition of the present invention can be suitably used as a reflector having a function of reflecting light, for example, a reflector for an LED or a lighting fixture.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Production Example 1 (Synthesis of polyparaxylylene sebacamide (PXD10))>
8950 g (44 mol) of sebacic acid (TA grade manufactured by Ito Oil Co., Ltd.) precisely weighed in a reaction vessel equipped with a stirrer, a partial condenser, a cooler, a thermometer, a dropping device and a nitrogen introduction tube, and a strand die, hypophosphorous acid Sodium monohydrate (13.401 g) (phosphorus atom concentration in the polyamide resin as 300 ppm) and sodium acetate (10.340 g) were weighed and charged. The molar ratio of sodium hypophosphite and sodium acetate is 1.0. After sufficiently purging the inside of the reaction vessel with nitrogen, the pressure was increased to 0.3 MPa with nitrogen, and the temperature was raised to 160 ° C. while stirring to uniformly melt sebacic acid.
Next, 6026 g (44 mol) of paraxylylenediamine (PXDA) was added dropwise over 170 minutes with stirring. During this time, the internal temperature was continuously raised to 281 ° C. In the dropping step, the pressure was controlled to 0.5 MPa, and the generated water was removed from the system through a partial condenser and a cooler. The temperature of the partial condenser was controlled in the range of 145 to 147 ° C. After completion of the dropwise addition of paraxylylenediamine, the pressure was reduced at a rate of 0.4 MPa / hr, and the pressure was reduced to normal pressure in 60 minutes. During this time, the internal temperature rose to 299 ° C. Thereafter, the pressure was reduced at a rate of 0.002 MPa / min, and the pressure was reduced to 0.08 MPa in 20 minutes. Thereafter, the reaction was continued at 0.08 MPa until the torque of the stirring device reached a predetermined value. The reaction time at 0.08 MPa was 10 minutes. Thereafter, the inside of the system was pressurized with nitrogen, and the polymer was taken out from the strand die and pelletized to obtain a polyamide resin. The obtained polyamide resin PXD10 had a melting point of 290 ° C. and a glass transition point of 75 ° C. The number average molecular weight was 16,000.
Hereinafter, this polyamide resin is referred to as “PXD10”.

<Production Example 2> (Synthesis of polyamide (MP6))
After adipic acid is heated and dissolved in a reactor under a nitrogen atmosphere, the contents are stirred and paraxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) and metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) While gradually adding a mixed diamine having a molar ratio of 3: 7 under pressure (0.35 Mpa) so that the molar ratio of diamine and adipic acid (manufactured by Rhodia) is about 1: 1, Was raised to 270 ° C. After completion of the dropping, the pressure was reduced to 0.06 MPa and the reaction was continued for 10 minutes to adjust the amount of the component having a molecular weight of 1,000 or less. Thereafter, the contents were taken out in a strand shape and pelletized with a pelletizer to obtain polyamide. The obtained polyamide resin MP6 had a melting point of 254 ° C. and a glass transition point of 85 ° C. The number average molecular weight was 15,000.
Hereinafter, this polyamide resin is referred to as “MP6”.

(A) Polyamide resin polymetaxylylene adipamide (MXD6): manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name “MX Nylon 6000”,
A melting point of 240 ° C., a glass transition point of 85 ° C., and a number average molecular weight of 15000 were used. Hereinafter, this polyamide resin is referred to as “MXD6”.

(B) Inorganic filler and reinforcing material glass fiber: 03T-296GH, manufactured by Nippon Electric Glass

(C) White pigment titanium dioxide: manufactured by Ishihara Sangyo, CR-63

(D) Antioxidant Irganox 1098: phenolic antioxidant, BASF HostanoxO3: phenolic antioxidant, Clariant Japan SumilizerGP: phenolic antioxidant, Sumitomo Chemical PEP36: phosphorus antioxidant, Adeka PEP- Q: Phosphorous antioxidant, Adeka Nocrack CD: Aromatic amine antioxidant, Sumitizer TPM manufactured by Ouchi Shinsei Chemical Industries, Sumitomo Chemical Nocrack MBZ: Sulfur antioxidant, Eau Ouchi Made by chemical industry

(F) Alkaline earth metal hydroxide magnesium hydroxide: Kismer 5E, manufactured by Kyowa Chemical

Release agent 405MP: Mitsui Chemicals (polyethylene wax)

<Compound>
Each component was weighed so as to have the composition shown in the table to be described later, components other than glass fiber were blended with a tumbler, charged from the root of a twin screw extruder (Toshiki Machine Co., Ltd., TEM26SS), and melted. Later, glass fibers were side fed to form resin pellets. The temperature setting of the extruder was 300 ° C for PXD10 and 280 ° C for MXD6 and MP6.

<Reflectance (450 nm)>
A test piece of 60 mm × 60 mm × 2 mmt was produced by injection molding. The reflectance at a wavelength of 450 nm was measured using a visible ultraviolet spectrometer, manufactured by Shimadzu Corporation, UV-3100PC. 450 nm is a wavelength region of a blue light emitting diode. If the molded product has an initial reflectance of 50% or more, it is judged that the reflectance is good, and it can be judged that there is a possibility that it can be used for applications requiring reflectance.

<Reflection retention>
A test piece of 60 mm × 60 mm × 2 mmt was produced by injection molding. The test piece was held in a hot air oven at 170 ° C. for 100 hours, and a heat aging test was performed. After the test, the reflectance was measured in the same manner as described above. Those having a reflectance of 35% or more can be expected to be used for a long time.

<Solder heat resistance>
The test piece of the said plate test piece (0.8mmt) was produced, the test piece was immersed for 3 minutes using the soldering bath of 240 degreeC, and the degree of deformation | transformation was confirmed visually. Evaluation was performed as follows.
○: Even when immersed for 3 minutes, there is no deformation and the appearance is good. Δ: Deformation is slightly observed at the corner of the test piece within 3 minutes. X: The test piece is reliably deformed within 3 minutes.

As is clear from the above table, when the polyamide resin composition of the present invention was used, the reflectance was excellent regardless of before and after aging, and an excellent solder heat resistance test was obtained.
Further, in Example 1, when Irganox 1098 was replaced with the same amount of Kismer 5E, in Example 1, the reflectance was excellent regardless of before and after aging, and an excellent solder heat resistance test was obtained.
In Example 1, when Irganox 1098 was replaced with Kismer 5E and the blending amount of Skimmer 5E was 1.5 parts by weight, the reflectance was excellent regardless of before and after aging, and an excellent solder heat resistance test was obtained. It was.
In Example 1, when Irganox 1098 was replaced with PEP36 and the blending amount of PEP36 was 0.4 parts by weight, the reflectance was excellent before and after aging, and an excellent solder heat resistance test was obtained. .

Claims (14)

(A) 100 parts by weight of a polyamide resin comprising a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
(D) A polyamide resin composition containing 0.1 to 15 parts by weight of an antioxidant. (A) 100 parts by weight of a polyamide resin comprising a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
A polyamide resin composition comprising 0.1 to 20 parts by weight of at least one selected from (E) alkali metal hydroxides and (F) alkaline earth metal hydroxides. (A) 100 parts by weight of a polyamide resin comprising a diamine unit composed of paraxylylenediamine and a dicarboxylic acid unit containing 70 mol% or more of a linear aliphatic dicarboxylic acid having 6 to 18 carbon atoms;
(B) 15 to 100 parts by weight of at least one selected from inorganic fillers and reinforcing materials;
(C) 10 to 100 parts by weight of a white pigment;
(D) 0.1 to 15 parts by weight of an antioxidant;
A polyamide resin composition comprising 0.1 to 20 parts by weight of at least one selected from (E) alkali metal hydroxides and (F) alkaline earth metal hydroxides. (B) The polyamide resin composition according to any one of claims 1 to 3, wherein the inorganic filler and the reinforcing material include at least one selected from glass fiber, wollastonite, calcium carbonate, talc and mica. object. (C) The polyamide resin composition according to any one of claims 1 to 4, wherein the white pigment contains at least one selected from titanium oxide, zinc oxide, zinc sulfide, barium sulfide, and potassium titanate. (D) The antioxidant comprises at least one selected from a phenolic antioxidant, a phosphorus antioxidant, an aromatic amine antioxidant, a sulfur antioxidant and an imidazole antioxidant. Item 6. The polyamide resin composition according to any one of Items 1 and 3-5. (C) The polyamide resin composition according to any one of claims 1 to 6, wherein the white pigment is titanium oxide surface-treated with an inorganic material and / or an organic material. (D) The antioxidant is at least one selected from a phenolic antioxidant, a phosphorus antioxidant, a sulfur antioxidant, and an imidazole antioxidant, 8. The polyamide resin composition according to any one of 7 above. (D) The polyamide resin composition according to any one of claims 1 and 3 to 8, wherein at least one of the antioxidants is a phenolic antioxidant. (D) At least one of the antioxidants is N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide). The polyamide resin composition according to any one of the above. (A) Polyamide resin composition of any one of Claims 1-10 whose melting point of a polyamide resin is 280 degreeC or more. (A) The polyamide resin composition of any one of Claims 1-11 whose dicarboxylic acid unit of a polyamide resin is sebacic acid. A molded article formed by molding the polyamide resin composition according to any one of claims 1 to 12. The molded article according to claim 13, which is used for a light emitting diode.