JP5352201B2 - Flame retardant polyamide resin composition and molded article using the same - Google Patents

Description

The present invention relates to a flame retardant polyamide resin composition comprising a polyamide resin blended with a core-shell type compound and a flame retardant comprising a plurality of components. Since this composition is excellent in light discoloration resistance, it is suitable for the production of light-colored molded products, and also has excellent laser marking properties, so it can be used for the production of light-colored molded products with laser marking on the surface. Particularly preferred.

In general, polyamide resins are excellent in moldability, mechanical properties, electrical properties, and chemical resistance, so they are widely used in applications such as automotive electrical components and electrical / electronic devices by incorporating flame retardants. . Polyester resin such as polybutylene terephthalate resin is also used in this field, but polyamide resin generally has both electrical insulation characteristics and toughness, so it has terminals that allow current to flow over 100 volts. Polyamide resins are preferred over polyester resins for electrical and electronic parts that require high toughness, such as general household electrical wiring parts such as no-fuse breakers, outlets, switches, and lamp sockets.

A material used for a case such as a breaker is required to have impact resistance as well as rigidity as mechanical characteristics. In addition, since various labels are often applied to the product, the laser marking characteristics are required to be good, and therefore the molded product needs to have a good appearance surface.

Furthermore, recently, coloring to a color tone other than black has been required as a sign for preventing misidentification of electric and electronic parts and as a sign for identifying parts by their performance. Further, electrical and electronic parts are required to have flame retardancy of flame retardancy standard V-2 or higher, preferably V-0, in the UL94 test.

However, the polyamide resin is likely to cause photodiscoloration, and even if an ultraviolet absorber or the like is added, it is not very effective. In general, a halogen-based flame retardant is used to make the resin flame-retardant. However, the flame-retardant polyamide resin molded product containing the halogen-based flame retardant has a problem that the light discoloration resistance is further deteriorated.

This halogen flame retardant generates dioxins when used products are incinerated, and may cause environmental pollution. Therefore, various flame retardants using non-halogen flame retardants have been studied. No law has been found. In addition, since light discoloration is particularly noticeable in light-colored systems, a material that is light-colored and does not cause light discoloration is required. However, no effective solution has yet been found in this respect.

On the other hand, it is known that an elastomer is blended as a method for improving the impact resistance of a polyamide resin. In particular, blending an olefin elastomer having a high impact resistance improving effect even in a low temperature range such as −40 ° C. is widely performed. However, since the flame retardancy decreases when an olefin elastomer is blended, it is necessary to increase the blending amount of the flame retardant, but the light discoloration resistance of the polyamide resin composition is further decreased by increasing the blending amount of the flame retardant. There was a problem of doing.

As another method for improving the impact resistance of the polyamide resin, it is also known to use a core-shell type compound in which a rubber-like core layer is covered with a hard shell layer. For example, Patent Document 1 shows a composition in which a core-shell type compound is blended with nylon 6, and it is shown that there is an effect of improving impact resistance. Patent Document 2 discloses a composition in which a core-shell type compound is blended with nylon 9T having a high melting point of 317 ° C., and shows excellent properties such as impact resistance, heat resistance, and hot water resistance. ing.

However, these patent documents do not describe characteristics that affect the light discoloration resistance and laser marking properties.

It is also known to blend a core-shell type compound with a resin other than a polyamide resin. For example, Patent Document 3 discloses a composition comprising a thermoplastic polyester resin, a core-shell type compound, a halogen flame retardant, and a fibrous filler. A comparison between a core-shell type compound and an elastomer of an ethylene ethyl acrylate copolymer is shown, but it is only shown that heat shock resistance is improved. There is no description.

JP-A-5-339462 JP 2000-186204 A JP-A-8-183896

An object of the present invention is to provide a flame retardant polyamide resin composition which is flame retardant with a non-halogen flame retardant and is excellent in light discoloration resistance, laser marking property, and impact resistance, and has an excellent balance of physical properties. That is. In particular, it is to provide a flame-retardant polyamide resin composition that gives a molded product with little photodiscoloration even in a light-colored molded product.

The present inventors provide a core-shell type compound having a core layer containing an acrylic rubber, a polyorganosiloxane rubber or a composite rubber thereof, and a flame retardant comprising a plurality of non-halogen components, with respect to the polyamide resin. The present inventors have found that a polyamide resin composition having excellent light discoloration resistance and laser marking properties can be obtained without reducing flame retardancy by combining and blending, and the present invention has been completed.

That is, the gist of the present invention is as follows.
(A) Polyamide resin For 100 parts by weight,
(B) 1 to 35 parts by weight of a core-shell type compound having a core layer containing a rubber selected from the group consisting of acrylic rubber, polyorganosiloxane rubber and composite rubber thereof (C) ), 5 to 100 parts by weight of a flame retardant comprising (c) and (d), and (a) a reaction product or adduct of melamine and phosphoric acid (b) 0.5 to 2 relative to (a) above Phosphinic acid metal salt which is a metal salt selected from the group consisting of calcium, magnesium, aluminum and zinc of phosphinic acid represented by the general formula (1) or (2) 5 times by weight

（一般式（１）及び（２）において、Ｒ^１及びＲ^２はそれぞれ独立して、炭素数１〜６のアルキル基、又は炭素数６〜１０のアリール基を表し、Ｒ^３は炭素数１〜１０のアルキレン基、炭素数６〜１０のアリーレン基又はこれらの混合基を表す。）
（ｃ）上記（ａ）に対して０．０１〜１重量倍のホウ酸金属塩
（ｄ）上記（ａ）に対して０〜２重量倍のシアヌル酸メラミン系化合物
（Ｄ）繊維状強化充填材１７０重量部以下
を配合してなることを特徴とする、難燃性ポリアミド樹脂組成物に存する。また本発明の他の要旨は、この難燃性ポリアミド樹脂組成物を成形してなる成形品、特に表面にレーザーによるマーキングを有する成形品に存する。

(In General Formulas (1) and (2), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R ³ represents 1 carbon atom. Represents an alkylene group having 10 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a mixed group thereof.)
(C) 0.01-1 times by weight borate metal salt relative to (a) above (d) 0-2 times by weight melamine cyanurate compound (D) Fibrous reinforcing filling relative to (a) above It exists in the flame-retardant polyamide resin composition characterized by mix | blending 170 weight part or less of material. Another gist of the present invention resides in a molded product obtained by molding this flame retardant polyamide resin composition, particularly a molded product having a laser marking on the surface.

According to the present invention, it is possible to provide a light-colored polyamide resin composition which is rich in flame retardancy and has excellent light discoloration resistance, laser marking property and impact resistance. And from this resin composition, resin molded products colored in various colors can be obtained. Therefore, it is possible to improve the safety of operation of electric and electronic parts by using the color as an identification mark. .

Specific examples of such a resin molded article using the polyamide resin composition of the present invention include no fuse breakers, lamp sockets, plugs, outlets, connectors and the like as examples of electric and electronic parts.

(A) Polyamide resin As the polyamide resin, a polyamide resin obtained by polycondensation of ω-amino acids or lactams thereof or dibasic acids and diamines as raw materials is used.

Examples of ω-amino acids include ε-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the lactam include ε-caprolactam, enantolactam, capryl lactam, lauryl lactam, α-pyrrolidone, and α-piperidone.

Dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadioic acid, hexadecenedioic acid, eicosandioic acid, eicosadienedioic acid , Diglycolic acid, 2,2,4-trimethyladipic acid, xylylene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid.

Examples of diamines include hexamethylene diamine, tetramethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4 (or 2,4,4) -trimethylhexamethylene diamine, bis- (4 4'-aminocyclohexyl) methane, metaxylylenediamine.

Polyamide resins generally used include 6 nylons mainly composed of ε-caprolactam or ε-aminocaproic acid, 66 nylons mainly composed of equimolar salts of hexamethylenediamine and adipic acid, hexamethylenediamine and adipic acid. 6/66 copolymerized nylon mainly composed of equimolar salt and ε-caprolactam or ε-aminocaproic acid, MXD6 nylon mainly composed of metaxylylenediamine and adipic acid, etc. Polyamide resin can be used. These may be used alone or in combination.

In the present invention, it is particularly preferable to use a polyamide resin having a crystallization temperature in the range of 140 to 180 ° C, particularly in the range of 150 to 175 ° C. Here, the crystallization temperature means that a polyamide resin (in the case of mixing a plurality of polyamide resins, the mixture is shown) is melted and extruded into a strand shape, cooled and solidified, and then cut into pellets. When the temperature was lowered using a sample as a sample, the temperature was raised to 270 ° C. at a rate of temperature rise of 20 ° C./min using a DSC 20 manufactured by Seiko Electronics Industry Co., Ltd., held at 270 ° C. for 10 minutes, and then lowered at 20 ° C./min. The temperature of the exothermic peak of is shown.

The crystallization temperature of 6 nylon is about 170 ° C., the crystallization temperature of 6/66 nylon (copolymer weight ratio 85/15) is about 150 ° C., and the crystallization temperature of 66 nylon is about 213 ° C. As the polyamide resin used in the present invention, 6 nylon, 6/66 nylon or a mixture thereof is preferable. In addition, the terminal of the polyamide resin may be sealed with a carboxylic acid or an amine compound.

The polyamide resin preferably has a viscosity of 70 to 190 ml / g measured in 96% sulfuric acid at a concentration of 1% by weight and a temperature of 23 ° C. using a polyamide resin pellet used for measurement of the crystallization temperature as a sample. In particular, it is preferably 70 to 120 ml / g, particularly preferably 72 to 115 ml / g.

In general, since the viscosity of commercially available polyamide resin is about 80 to 350 ml / g, the polyamide resin preferably used in the present invention has a relatively low molecular weight. In addition, if the viscosity of the polyamide resin used is too low, the mechanical strength of the molded product formed by molding the resin composition of the present invention is excessively lowered. Conversely, even if the viscosity is too high, the flow of the resin composition In addition to the deterioration of the surface properties, the appearance of the molded product surface is also deteriorated, resulting in poor laser marking performance, which may make it unsuitable for application of laser marking for product identification such as a case such as a breaker. .

(B) Core-shell type compound The core-shell type compound includes a core layer containing a rubber-like elastomer component and a resin that is a hard shell layer. In the present invention, the core layer of the core-shell type compound needs to contain acrylic rubber, polyorganosiloxane rubber, or a composite rubber thereof. In particular, in the present invention, the core layer is preferably composed of only these.

In addition to these, the core layer may contain other rubber components as long as the object of the present invention is not impaired. However, diene rubbers such as polybutadiene require attention because the diene component may decompose and discolor during molding of the resin composition.

For the core layer, a mixture of these rubber components or a composite rubber obtained by copolymerization / graft polymerization can be used. Among them, two types of rubber components are integrated by chemical bonding, such as copolymerization / graft polymerization. It is preferable to use a composite rubber. The average particle diameter of the rubber of the core layer is preferably 1 μm or less, particularly preferably 0.1 to 0.6 μm as measured by a laser diffraction method. If the average particle size exceeds 1 μm, the mechanical properties of the resin composition obtained may be insufficient. In addition, in this specification, the average particle diameter by a laser diffraction method shows a volume average particle diameter.

The acrylic rubber component and the polyorganosiloxane rubber component used for the core layer can be used in any ratio. Generally, when the polyorganosiloxane rubber component in the core layer exceeds 99% by weight, the appearance of the surface of a molded article using the resulting resin composition may be deteriorated, and the laser marking property may be deteriorated. However, from the viewpoint of flame retardancy of the resin composition, it is preferable that the amount of the polyorganosiloxane rubber component is large. Overall, the weight ratio of the acrylic rubber component to the polyorganosiloxane rubber component is preferably the former / the latter = 100/0 to 15/85, and more preferably 99/1 to 30/70.

As the acrylic rubber, one obtained by copolymerizing an acrylic ester such as butyl acrylate and a small amount of a crosslinkable monomer such as butylene glycol diacrylate is used. As the acrylic acid ester, methyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate and the like are used in addition to butyl acrylate. In addition to butylene glycol diacrylate, crosslinkable monomers include butylene glycol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, oligoethylene glycol diacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, trimethylol Allyl compounds such as poly (meth) acrylates such as methylolpropane trimethacrylate, allyl acrylate, allyl methacrylate, diallyl malate, diallyl fumarate, diallyl itanilate, monoallyl malate, monoallyl fumarate, triallyl cyanurate Etc. are used.

The polyorganosiloxane rubber is an organosiloxane polymer and is usually a polymer of a cyclic organosiloxane of trimer or higher. The polymerization raw material is preferably a 3 to 6 mer. For example, hexamethyltricyclosiloxane, octamethyltetracyclosiloxane, decamethylpentacyclosiloxane, dodecamethylhexacyclosiloxane, trimethyltriphenyltrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetracyclosiloxane and the like are used. As the crosslinking agent to be copolymerized with these, trifunctional or tetrafunctional ones, that is, trialkoxyalkyl, arylsilane or tetraalkoxysilane are used. For example, trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetrabutoxysilane and the like are used. Tetraalkoxysilane is preferably used as the crosslinking agent, and tetraethoxysilane is particularly preferred.

The shell layer of the core-shell type compound formed of a hard resin is generally made of a (co) polymer of a vinyl compound. That is, the shell layer is formed by polymerizing or copolymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, a methacrylic acid ester monomer, an acrylic acid ester monomer, etc. on the core layer. Is.

The vinyl monomer of the shell layer may or may not have a functional group. Non-functional groups include methacrylic acid esters such as methyl methacrylate and 2-ethylhexyl methacrylate; acrylic acid esters such as methyl acrylate, ethyl acrylate and butyl acrylate; styrene, halogen Examples thereof include aromatic alkenyl compounds such as substituted styrene, α-methylstyrene, and vinyl toluene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile.

Examples of those having a functional group include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, allyl glycidyl ether, hydroxyalkyl (meth) acrylate glycidyl ether, and polyalkylene glycol. Examples thereof include epoxy group-containing compounds such as (meth) acrylate glycidyl ether and glycidyl acrylate, and carboxyl group-containing compounds such as acrylic acid and methacrylic acid. From the viewpoint of compatibility with the polyamide resin, it is preferable to copolymerize a small amount of an epoxy group or a carboxyl group-containing vinyl monomer in the shell layer.

The rubber layer and the shell layer of the core-shell type compound are preferably bonded by graft bonding, and this graft bonding adds a graft crossing agent that reacts with the shell layer during polymerization of the rubber layer to give a reactive group to the rubber layer. Then, a shell layer is formed.

The graft crossing agent is a compound having a group that reacts with a vinyl bond. In the case of an acrylic rubber, it can be used as the above-mentioned crosslinking monomer, but in the case of a polyorganosiloxane rubber, it has a vinyl bond. An organosiloxane or an organosiloxane having a thiol group is used. It is preferable to use acryloyloxysiloxane, methacryloyloxysiloxane, vinylsiloxane, etc., which are organosiloxanes having vinyl bonds.

Among the (meth) acryloyloxysiloxanes, methacryloyloxysiloxane is preferable, and specific examples thereof include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, and γ-methacryloyl. Examples include methacryloyloxyalkylsiloxanes such as oxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethoxysilane, γ-methacryloyloxypropyldiethoxymethylsilane, and δ-methacryloyloxybutyldiethoxymethylsilane.

Examples of vinyl siloxane include vinyl methyl dimethoxy silane and vinyl trimethoxy silane. Examples of mercaptosiloxane that is an organosiloxane having a thiol group include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyldiethoxyethylsilane.

Examples of the core-shell type compound containing a composite rubber or polyorganosiloxane rubber in the core layer, which is a core-shell type compound preferably used in the present invention, include, for example, JP-A-5-5055 and JP-A-5-25377. It can be produced by the production method described in Japanese Unexamined Patent Publication No. 2001-261945.

The core-shell type compound is blended in an amount of 1 to 35 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the polyamide resin. If the amount is less than 1 part by weight, the intended effects of improving the light discoloration resistance and laser marking properties of the present invention cannot be obtained. If the amount is too large, the heat resistance is lowered and the mechanical properties such as rigidity are lowered. . Among them, in the present invention, it is most preferable to add 5 to 20 parts by weight with respect to 100 parts by weight of the polyamide resin.

(C) Flame retardant In the present invention, a flame retardant having the following three components (a) to (c) is essential. In addition to these three components, the flame retardant preferably further contains (d) below.

(A) a reaction product or adduct of melamine and phosphoric acid;
The reaction product or adduct of melamine and phosphoric acid is composed of orthophosphoric acid, polyphosphoric acid such as pyrophosphoric acid and metaphosphoric acid, and phosphoric acids such as phosphorous acid and hypophosphorous acid. , Reaction products or adducts of melamine (C ₃ N ₆ H ₆ ) and condensates thereof such as melam and melem (hereinafter, these may be referred to simply as a reaction product). Show.

From the viewpoint of the heat resistance of the reaction product, the phosphoric acid is preferably polyphosphoric acid, particularly polyphosphoric acid having a condensation degree of 3 to 50. The reactant may be a condensate obtained by further condensing the reactant of phosphoric acid and melamine. The phosphorus atom content in the reaction product is preferably 8 to 18% by weight from the viewpoint of reducing mold contamination when the resin composition is molded.

As for the reaction product of melamine and phosphoric acid, for example, melamine and phosphoric acid are mixed so that the content of phosphorus atoms in the reaction product is 8 to 18% by weight, and this is poured into water to form a slurry. They can be obtained by mixing well to form both reactants in the form of fine particles, followed by filtration, washing and drying. Moreover, after drying, you may give baking and grinding | pulverization further.

The reaction product of melamine and phosphoric acid has an average particle diameter of 100 μm or less, particularly 50 μm or less, particularly 0.5 μm or less by laser diffraction from the viewpoint of mechanical strength and appearance of a molded product obtained from the resin composition. It is preferable to use one having a thickness of ~ 20 μm.

The reaction product of melamine and phosphoric acid is blended at least 2 parts by weight, usually 5 parts by weight or more with respect to 100 parts by weight of the (A) polyamide resin. If the blending amount is less than 2 parts by weight, the flame retardancy cannot be sufficiently improved. The upper limit of the amount is 60 parts by weight, preferably 50 parts by weight. If it exceeds 60 parts by weight, gas generation and other obstacles are likely to occur during the molding process of the resin composition. The most preferable blending amount is 8 to 40 parts by weight, particularly 15 to 30 parts by weight.

(B) phosphinic acid salt;
The phosphinate used in the present invention is a salt of an anion represented by the following general formula (1) or (2) and a metal ion selected from the group consisting of calcium ion, magnesium ion, aluminum ion, and zinc ion. is there.

In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms. R ³ represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a mixed group thereof.

Examples of the alkyl group represented by R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a tert-butyl group, and an n-pentyl group. Examples of the aryl group include a phenyl group, a methylphenyl group, an ethylphenyl group, and a naphthyl group. R ¹ and R ² are preferably a methyl group, an ethyl group, a phenyl group, or the like.

Examples of the alkylene group represented by R ³ include a methylene group, an ethylene group, an n-propylene group, an i-propylene group, an n-butylene group, and an n-octylene group. Examples of the arylene group include a 1,4-phenylene group and a 2,6-naphthylene group. Examples of these mixed groups include a 4-methylenephenyl group.

The phosphinic acid salt represented by the general formula (1) includes calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, ethylmethylphosphine. Aluminum oxide, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, methyl-n -Aluminum propylphosphinate, zinc methyl-n-propylphosphinate,

Examples include calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate.

As the phosphinic acid salt represented by the general formula (2), those in which n is 0 are preferable. For example, methylene bis (methylphosphinic acid) calcium, methylenebis (methylphosphinic acid) magnesium, methylenebis (methylphosphinic acid) aluminum, methylenebis (Methylphosphinic acid) zinc, phenylene-1,4-bis (methylphosphinic acid) calcium, phenylene-1,4-bis (methylphosphinic acid) magnesium, phenylene-1,4-bis (methylphosphinic acid) aluminum, phenylene-1,4 -Bis (methylphosphinic acid) zinc etc. are mentioned.

Of these phosphinic acid salts, calcium salts, aluminum salts and zinc salts are preferred. Most preferred from the viewpoint of flame retardancy and electrical properties are aluminum ethyl methylphosphinate, aluminum diethylphosphinate, and zinc diethylphosphinate. The phosphorus atom content of the phosphinate is preferably 15% by weight or more from the viewpoint of less mold contamination during molding.

The phosphinic acid salt generally has an average particle size of 100 μm or less, preferably 80 μm or less, from the viewpoint of mechanical strength and appearance of the molded product. From the viewpoint of exhibiting high flame retardancy and remarkably improving the strength of the molded product, it is most preferable to use those having an average particle size of 0.5 to 50 μm.

The phosphinate is a well-known flame retardant, but exhibits excellent flame retardancy and electrical properties when used in combination with the reaction product of melamine and phosphoric acid (a) as in the present invention. The phosphinic acid salt is blended so as to be 0.5 to 2.5 times by weight, preferably 0.6 to 2.4 times by weight with respect to the reaction product of (a) melamine and phosphoric acid. (A) As a compounding quantity with respect to 100 weight part of polyamide resins, it is 2-70 weight part normally, 12-50 weight part, Especially 20-40 weight part is preferable. If the blending amount is small, the flame retardancy is not sufficiently developed. On the other hand, if the amount is too large, problems such as gas generation occur during the molding process.

(C) Boric acid metal salt As the boric acid metal salt, a salt of boric acid such as orthoboric acid, metaboric acid and tetraboric acid and a metal such as alkali metal, alkaline earth metal and zinc is usually used. For example, alkali metal salts such as sodium tetraborate and potassium metaborate, alkaline earth metal salts such as calcium borate, magnesium borate and barium borate, zinc borate and the like are used. The metal borate salt may be a hydrate. For example, 2ZnO · 3B ₂ O ₃ · xH ₂ O (x = 3.3 to 3.7), 4ZnO · B ₂ O ₅ · H ₂ O, or the like is preferably used.

As the boric acid metal salt, one having a number average particle diameter of 30 μm or less is usually used from the viewpoint of mechanical strength and appearance of the molded product. In view of obtaining a molded article having a stable impact strength, it is preferable to use one having an average particle diameter of 1 to 20 μm. The metal borate salt is blended so as to be 0.01 to 1 times by weight, preferably 0.05 to 0.5 times by weight with respect to the reaction product or adduct of (a) melamine and phosphoric acid. (A) Although it is 0.1-30 weight part normally as a compounding quantity with respect to 100 weight part of polyamide resins, 1-20 weight part, especially 1-5 weight part are preferable. When the blending amount is small, flame retardancy and tracking resistance are not sufficiently exhibited. On the other hand, if the blending amount is too large, the impact strength decreases.

In addition to the components (a) to (c) described above, it is preferable that the resin composition of the present invention further contains (d) a melamine cyanurate compound. The melamine cyanurate compound is cyanuric acid or a derivative thereof, for example, an ester of a compound in which 1 to 2 of its OH groups are esterified with melamine, and usually equimolar reactants of both are used. For example, an equimolar amount of cyanuric acid and melamine are reacted in water at 90 to 100 ° C., and the resulting precipitate is filtered, dried and pulverized. Incidentally it is also possible to use a material obtained by further substituting the OH and NH ₃ group is a functional group of the melamine cyanurate.

Since melamine cyanurate is decomposed when heated to a high temperature, the preparation of the resin composition and the production of the molded product are carried out at a temperature not exceeding 270 ° C. when melamine cyanurate is blended. However, if the temperature is low, the fluidity of the resin composition, particularly the resin composition containing the fibrous reinforcing filler is lowered. Therefore, it is preferable to use a resin having high fluidity even at a low temperature such as polyamide 6 as the polyamide resin. preferable.

The melamine cyanurate compound is preferably added in an amount of 0.2 times by weight or more with respect to the reaction product of melamine and phosphoric acid of (a) in order to fully express the effect of improving flame retardancy by compounding. From the viewpoint of moldability, the upper limit of the blending amount is 2 times by weight to the reaction product or adduct of (a) melamine and phosphoric acid, but 1.8 times by weight or less, particularly 0 It is preferable to use at 5 weight times or less. (A) As a compounding quantity with respect to 100 weight part of polyamide resins, although it is 0.4-40 weight part normally, 3-25 weight part, especially 3-10 weight part are preferable.

(C) The flame retardant is blended in an amount of 5 to 100 parts by weight with respect to 100 parts by weight of the polyamide resin (A) in view of the effect on flame retardancy and glow wire properties. That is, by adding 5 parts by weight or more, flame retardancy and glow wire properties can be improved, and by making the blending amount 100 parts by weight or less, generation of gas and mold deposit during molding processing is avoided. And good mechanical strength can be expressed in a molded article. (A) The compounding quantity of (C) a flame retardant with respect to 100 weight part of polyamide resins is 10-90 weight part, Especially 30-80 weight part is preferable.

(D) Fibrous reinforcing filler It is preferable to further add a fibrous reinforcing filler to the flame-retardant polyamide resin composition of the present invention in order to improve mechanical strength. Examples of the fibrous reinforcing filler include glass fiber, carbon fiber, basalt fiber, silica-alumina fiber, zirconia fiber, boron fiber, boron nitride fiber, and silicon nitride potassium titanate fiber. Among these, it is preferable to use glass fiber in terms of giving a resin composition having high strength and rigidity. Two or more kinds of fibrous reinforcing fillers may be used in combination. In addition, since the blending of the fibrous reinforcing filler improves the flame retardancy of the obtained resin composition, there is an effect that the blending amount of the flame retardant can be reduced.

If the diameter of the fibrous reinforcing filler is too thick, it is not flexible and is too thin, for example, it is difficult to obtain one having a diameter of less than 1 μm. Therefore, the diameter is usually 1 to 100 μm, preferably 2 to 50 μm. Usually, those having an average diameter of 3 to 30 μm, particularly 5 to 20 μm are used because they are easily available and have a great effect as a reinforcing material.

Further, a fibrous reinforcing filler having an irregular cross-sectional shape such as an eyebrow shape or a flat shape may be used. The length of the fibrous reinforcing filler is preferably 0.1 mm or more from the viewpoint of the reinforcing effect. The upper limit of the length is usually 20 mm, and even when a length longer than this is used, it is broken and shortened when preparing a resin composition by melt-kneading.

Preferably, an average length of 0.3 to 5 mm is used. A fibrous reinforcing filler is usually used as a chopped strand obtained by cutting a number of these fibers into a predetermined length. In addition, since mixing | blending of carbon fiber provides electroconductivity to a resin composition, a glass fiber is used when a high resistance resin composition is desired.

The fibrous reinforcing filler may be used in combination with a sizing agent or a surface treatment agent. Such agents include epoxy compounds, silane compounds, titanate compounds and the like. The compounding amount of the fibrous reinforcing filler is 170 parts by weight or less, preferably 160 parts by weight or less with respect to 100 parts by weight of the polyamide resin, but 5 parts by weight or more should be blended in order to achieve the blending effect. In order to sufficiently achieve the blending effect, it is preferable to blend 50 parts by weight or more, particularly 80 parts by weight or more.

(E) Colorant The resin composition of the present invention can be blended with commonly used colorants, whereby it can be colored in any color tone from black to light, but has excellent light discoloration resistance. In order to make use of the characteristic that it is, it is preferable to use a light color by coloring with a non-black colorant. The light color means a colorimetric color difference meter having a lightness (L value) of 50 or more, preferably 70 or more when measured with a C light source.

Examples of the black pigment include carbon black (acetylene black, lamp black, thermal black, furnace black, channel black, ketjen black, gas black, oil black, etc.), graphite, titanium black, black iron oxide, and the like. Of these, carbon black is particularly desirable in terms of dispersibility, color developability, cost, and the like. A black pigment can be used individually or in combination of 2 or more types.

Examples of the non-black pigment include various inorganic pigments and organic pigments described later. These non-black pigments can be used alone or in combination of two or more. Examples of inorganic pigments include white pigments such as calcium carbonate, titanium oxide, zinc oxide, and zinc sulfide, yellow pigments such as cadmium yellow, yellow lead, titanium yellow, zinc chromate, ocher, and yellow iron oxide, red lip pigment, amber, Examples thereof include red pigments such as red iron oxide and cadmium red, blue pigments such as bitumen, ultramarine blue, and cobalt blue, and green pigments such as chrome green.

Also, as organic dyes and pigments, azo, azomethine, methine, indanthrone, anthraquinone, pyranthrone, flavanthrone, benzenethrone, phthalocyanine, quinophthalone, perylene, perinone, dioxazine, Organic dyes such as thioindigo, isoindolinone, isoindoline, pyrrole pyrrole and quinacridone can be used.

In order to sufficiently develop the excellent properties of the present invention that give a light-colored resin composition, among non-black colorants, white inorganic pigments such as titanium oxide, zinc sulfide, zinc oxide, and calcium carbonate are blended. Preferably, a pigment containing 50% by weight or more of these is used. Particularly preferred are those containing titanium oxide having a large shielding effect.

As the white pigment containing titanium oxide, it is preferable to use a pigment containing 80% by weight or more of titanium oxide from the viewpoint of whiteness and hiding properties among commercially available pigments. There are two types of titanium oxide, rutile type and anatase type, any of which can be used. The white pigment containing titanium oxide can also be used as a master batch in which this is blended in high concentration with polyamide. Further, in order to improve the dispersibility, a surface treatment may be applied.

The blending amount of the colorant is 0.1 to 20 parts by weight, preferably 0.3 to 18 parts by weight, and more preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the polyamide resin. When the blending amount is less than 0.1 part by weight, the concealing effect is insufficient, so that the light resistance and weather resistance of the resin composition are lowered. On the other hand, when it exceeds 20 parts by weight, the mechanical strength and flame retardancy are decreased. descend. One of the most preferred uses of the flame-retardant polyamide resin composition of the present invention is to produce a light-colored resin composition by blending 1 to 15 parts by weight of a white pigment with respect to 100 parts by weight of a polyamide resin. It is to be used for.

As previously described in (0004), it is widely practiced to further blend an elastomer with a polyamide resin blended with a flame retardant, but it is also possible to blend an elastomer into the resin composition of the present invention. it can. However, the blending of the elastomer does not reduce the flame retardancy so much, but needs to be careful because it reduces the laser marking property. However, the degree of the decrease is smaller than when no core-shell type compound is blended.

Other components In the polyamide resin composition according to the present invention, if necessary, other various resin additives can be blended as long as the effects of the present invention are not impaired. Examples include fluororesins as anti-dripping agents, copper and phosphorus heat stabilizers, hindered phenol-based antioxidants, mold release agents, weather resistance improvers, nucleating agents, foaming agents, Examples thereof include impact resistance improvers, lubricants, plasticizers, fluidity improvers, organic fillers, and dispersants. Moreover, thermoplastic resins other than polyamide resin, for example, polyethylene resin, polypropylene resin, polystyrene resin, thermoplastic polyester resin, polycarbonate resin, polyphenylene oxide resin, and the like can be added.

Method for producing polyamide resin composition The flame-retardant polyamide resin composition according to the present invention is obtained by melt-kneading the raw materials uniformly with a melting and kneading machine generally used for thermoplastic resins. Can be manufactured.

Examples of the melting / kneading machine include a single-screw or multi-screw extruder, a roll, and a Banbury mixer. In particular, the production method using a twin-screw extruder is preferable because the core-shell compound, flame retardant dispersion and the like are favorable, and all raw materials are weighed and mixed uniformly with a mixer or the like, and then put into the hopper of the twin-screw extruder. It can be produced by a general method of melting and kneading under reduced pressure at a cylinder temperature of 230 to 280 ° C. and pelletizing. The fibrous reinforcing filler is preferably added from the side feeder in the middle of the cylinder of the twin screw extruder, so that prevention of damage to the extruder and prevention of crushing of the filler can be expected. Therefore, side feed is preferable.

The method for producing a molded product from the resin composition of the present invention is not particularly limited, and a molding method generally employed for the resin composition, that is, an injection molding method, a hollow molding method, an extrusion molding method, a sheet molding method. Method, thermoforming method, rotational molding method, lamination molding method, press molding method and the like can be adopted, but injection molding method is preferable.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.

[Abbreviations and physical properties of each component used]
(A) Polyamide resin (A-1) Polyamide 6: Novamid 1010J manufactured by Mitsubishi Engineering Plastics
Viscosity 118ml / g, crystallization temperature 170 ° C

(B) Core-shell type compound (B-1) Polyorganosiloxane / polyalkyl (meth) acrylate composite rubber-based core-shell type compound grafted with an epoxy group-containing vinyl monomer (abbreviated as epoxy composite rubber core-shell);
It was produced in the same manner as Reference Example 1 in JP-A No. 2001-261945. The polyorganosiloxane / polyalkyl (meth) acrylate weight ratio of the core portion is about 4/6.

(B-2) Polyorganosiloxane rubber-based core-shell type compound grafted with an epoxy group-containing vinyl monomer (abbreviated as epoxy silicon rubber core-shell);
It was produced in the same manner as Reference Example 1 in JP-A-5-25377. The core portion is substantially only polyorganosiloxane rubber.

(B-3) Epoxy-containing acrylic rubber core-shell type compound (abbreviated as epoxy acrylic rubber core shell); Paraloid EXL-2314 manufactured by Rohm and Haas.

(B-4) Butadiene-based core-shell type compound (abbreviated as butadiene rubber core-shell):
Kane Ace FM manufactured by Kaneka Corporation. This has a core layer of butadiene rubber and is not a (B) core-shell compound used in the present invention.

(C) Flame retardant (a) Reaction product of melamine and phosphoric acid Melamine polyphosphate: Product name, melapre200 / 70, manufactured by Ciba Special Co., Ltd.
(B) Phosphinic acid salt Diethylphosphinate Aluminum: product name OP1230 manufactured by Clariant
(C) Boric acid metal salt Zinc borate: manufactured by Borax, Inc. Product name FireBrake 500
(D) Cyanuric melamine compound Cyanuric acid melamine: Nippon Synthetic Chemical Co., Ltd. Product name MX44
Table 1 shows the blending amount and blending ratio of each component.

(D) Fibrous reinforcing filler (D-1) glass fiber; manufactured by Owens Corning, product name DS1105, fiber diameter 10.5 μm

(E) White colorant (E-1) Titanium oxide: manufactured by Ishihara Sangyo Co., Ltd.
(E-2) Zinc sulfide: manufactured by Sacritis, trade name Sacritis HD

(F) Elastomer (F-1) Styrene-ethylene / butylene-styrene-g-maleic anhydride copolymer (hereinafter abbreviated as maleic anhydride-modified SEBS); % By weight, modified amount of maleic anhydride = 2,7% by weight.

(F-2) Styrene ethylene / butylene-styrene copolymer (hereinafter abbreviated as SEBS); manufactured by Asahi Kasei Co., Ltd., trade name Tuftec H1052, styrene content 20% by weight.

(F-3) Modified ethylene-butene copolymer (hereinafter abbreviated as maleic anhydride-modified EBR); manufactured by Mitsui Petrochemical Co., Ltd., trade name Tuffmer A-4085, maleic anhydride-modified product, maleic anhydride-modified amount 0, 8% by weight.

(F-4) ethylene-glycidyl methacrylate-methyl acrylate = 64/6/30 copolymer (hereinafter abbreviated as EGMA copolymer): product name Elvalloy, manufactured by Mitsui DuPont Polychemical Co., Ltd.

(G-1) SEBS-containing modified PPE

[Example 1 to Example 12, Comparative Example 1 to Comparative Example 6]
<Preparation of resin composition>
Various raw materials other than glass fibers were weighed in the blending amounts (parts by weight) shown in Table 2, and mixed with a tumbler mixer to obtain a mixture. The obtained mixture is supplied to the hopper of a twin screw extruder (manufactured by Nippon Steel Works, model: TEX30HCT, 30 mmφ), glass fiber is supplied through a side feeder, cylinder temperature is 260 ° C., screw rotational speed is 200 rpm, and discharge amount is 15 kg. The mixture was melted and kneaded under the conditions of / h to obtain pellets of a flame retardant polyamide resin composition.

[Evaluation methods for various physical properties]
1) When an ISO test piece was molded at a cylinder temperature of 260 ° C. and a mold temperature of 90 ° C. by using an injection molding machine (manufactured by Nippon Steel Works, model: J75ED) using a fluid flame retardant polyamide resin composition pellet. The maximum injection pressure was evaluated. The higher the value, the worse the fluidity.

Mechanical properties Flame retardant polyamide resin composition pellets were used to mold ISO test pieces with the above injection molding machine. Using this, bending strength, bending elastic modulus and notched Charpy impact strength were measured in accordance with ISO178 and ISO179-2.

In accordance with the flame retardant evaluation test UL-94 standard, a test piece having a size of 127 mm × 12.7 mm and a thickness of 1.5 mm was measured. The flame retardancy according to this test is the best with V-0 in order. These are denoted as V-1 and V-2.

4) Light resistance test Using a polyamide resin composition pellet, cut out to a required size from a 10 cm square × 3 cm thick flat plate test piece molded at a resin temperature of 270 ° C and a mold temperature of 90 ° C with the above injection molding machine. The test piece was irradiated with a xenon arc weather tester (1200 KJ / m ² , wavelength 340 nm) at a black panel temperature of 63 ° C. for 500 hours without rain. The color difference before and after the test of the test piece was measured as follows.

[Color difference evaluation]
The color change was evaluated using a spectrocolorimetric color difference meter (manufactured by Konica Minolta: CM-3600d), and the color difference (ΔE) of the following formula before and after the light resistance test. The lightness (L value) for lightness evaluation was also measured with the same testing machine.
ΔE = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2
The smaller the color difference (ΔE), the smaller the color change, and the greater the lightness (L value), the brighter the color and the lighter color system is determined.

5) Molded Product Surface Appearance Using a polyamide resin composition pellet, a disk-shaped molded product having a diameter of 100 mm × 2 mm was molded at a resin temperature of 270 ° C. and a mold temperature of 90 ° C. with the above-described injection molding machine. The surface appearance of the disk was visually observed and evaluated as ◯ for a clear image, △ for a slight fluctuation, and X for a fluctuation. ○ The above are judged to be practically acceptable.

6) Laser Marking Characteristics The disc-shaped molded product having a diameter of 100 mm and a thickness of 2 mm was marked using a laser marker SL475H marking manufactured by NEC Corporation. S141C was used as the laser oscillator. The type of laser is a continuous wave Nd: YAG laser. Maximum output is 50W or more. The scan speed was 200 mm / sec, and the ultrasonic Q switch was 2 kHz.

The marking situation (darkness, contrast) was judged visually and evaluated in the following five stages. In this evaluation, 4 or more is not practical. The evaluation results are shown in Table 3.
1: Clear, clear and good marking.
2: Good marking.
3: Slightly thin but good marking.
4: Marking that is decipherable but quite unclear.
5: Unprintable or unreadable.

Claims (16)

(A) For 100 parts by weight of polyamide resin,
(B) 1 to 35 parts by weight of a core-shell type compound having a core layer containing a rubber selected from the group consisting of an acrylic rubber, a polyorganosiloxane rubber and a composite rubber thereof,
(C) 5 to 100 parts by weight of a flame retardant comprising the following (a), (b), (c) and (d), and
(A) Reaction product or adduct of melamine and phosphoric acid (b) 0.5 to 2.5 times by weight of the anion moiety relative to (a) above is represented by the following general formula (1) or (2) Phosphinic acid salt, a metal salt selected from the group consisting of calcium, magnesium, aluminum and zinc

(In General Formulas (1) and (2), R ¹ and R ² each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R ³ represents 1 to 1 carbon atoms. 10 represents an alkylene group, an arylene group having 6 to 10 carbon atoms, or a mixed group thereof.)
(C) 0.01-1 times by weight borate metal salt relative to (a) above (d) 0-2 times by weight melamine cyanurate compound (D) Fibrous reinforcing filling relative to (a) above A flame-retardant polyamide resin composition comprising 0 to 170 parts by weight of a material. The flame-retardant polyamide resin composition according to claim 1, wherein the blending amount of (D) fibrous filler is 5 to 160 parts by weight with respect to 100 parts by weight of (A) polyamide resin. The amount of (d) cyanuric acid melamine compound is 0.2 to 2 times the weight of (a) reaction product or adduct of melamine and phosphoric acid. The flame-retardant polyamide resin composition described (B) The amount of the core-shell type compound having a core layer containing a rubber selected from the group consisting of an acrylic rubber, a polyorganosiloxane rubber and a composite rubber thereof is (A) based on 100 parts by weight of the polyamide resin. The flame retardant polyamide resin composition according to any one of claims 1 to 3, wherein the flame retardant polyamide resin composition is 5 to 30 parts by weight. The flame retardant polyamide resin composition according to any one of claims 1 to 4, wherein the blending amount of (C) the flame retardant is 10 to 90 parts by weight with respect to 100 parts by weight of the (A) polyamide resin. object. (A) A core-shell type compound having a core layer containing a rubber selected from the group consisting of (B) an acrylic rubber, a polyorganosiloxane rubber and a composite rubber based on 100 parts by weight of a polyamide resin. Part (C) 30-80 parts by weight of a flame retardant comprising the following (a), (b), (c) and (d), and (a) a reaction product or adduct of melamine and phosphoric acid (b) From the group consisting of calcium, magnesium, aluminum and zinc of the phosphinic acid whose anion portion is represented by the following general formula (1) or (2) 0.5 to 2.5 times by weight with respect to the above (a) Phosphinic acid salt selected metal salt

(In General Formulas (1) and (2), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R 3 represents 1 to 10 carbon atoms. An alkylene group, an arylene group having 6 to 10 carbon atoms, or a mixed group thereof.
(C) 0.05 to 0.5 times by weight of boric acid metal salt relative to (a) above (d) 0 to 2 times by weight of melamine cyanurate compound (D) fibrous relative to (a) above A flame retardant polyamide resin composition comprising 50 to 160 parts by weight of a reinforcing filler. The amount of (d) the melamine cyanurate compound is 0.2 to 0.5 times by weight with respect to the reaction product or adduct of (a) melamine and phosphoric acid. Flame retardant polyamide resin composition. (A) The blending amount of the reaction product or adduct of melamine and phosphoric acid is 2 to 60 parts by weight with respect to 100 parts by weight of the polyamide resin, and (b) the blending amount of the phosphinate is 2 to 70 parts by weight. The compounding amount of (c) metal borate is 0.1 to 30 parts by weight, and the compounding amount of (d) melamine cyanurate compound is 0.4 to 40 parts by weight. 6. The flame retardant polyamide resin composition according to any one of 6 above. (A) 8 to 40 parts by weight of the reaction product or adduct of melamine and phosphoric acid with respect to 100 parts by weight of the polyamide resin, and (b) 12 to 50 parts by weight of the phosphinic acid salt. The amount of (c) metal borate salt is 1 to 20 parts by weight, and the amount of (d) melamine cyanurate compound is 3 to 25 parts by weight. The flame-retardant polyamide resin composition described in 1. (A) The blending amount of the reaction product or adduct of melamine and phosphoric acid is 15 to 30 parts by weight with respect to 100 parts by weight of the polyamide resin, and (b) the blending amount of the phosphinate is 20 to 40 parts by weight. The amount of (c) metal borate is 1 to 5 parts by weight, and the amount of (d) melamine cyanurate compound is 3 to 10 parts by weight. The flame-retardant polyamide resin composition described in 1. (A) The polyamide resin has a crystallization temperature of 140 to 180 ° C., a viscosity of 70 to 190 ml / g measured in 96% sulfuric acid at a concentration of 1% by weight and a temperature of 23 ° C. The flame-retardant polyamide resin composition according to any one of claims 1 to 10. The flame retardant polyamide resin composition according to any one of claims 1 to 11, further comprising 1 to 15 parts by weight of a white pigment based on 100 parts by weight of the (A) polyamide resin. The flame retardant polyamide resin composition according to any one of claims 1 to 12, wherein the lightness (L value) is 50 or more. A molded article comprising the flame retardant polyamide resin composition according to any one of claims 1 to 13. The molded article according to claim 14, which has a laser marking on a surface thereof. The molded article according to claim 14, wherein the molded article is an electrical part or an electronic part.