JPH044257A - Resin composition and electronic part made thereof - Google Patents

Abstract

PURPOSE:To obtain a resin composition having excellent water-absorption characteristics, dimensional characteristics and reflow soldering resistance and suitable as a material for electronic part for surface-mounting by compounding a flame-retarded glass-fiber reinforced nylon 46 resin with a specific amount of a specific aliphatic polyamide resin. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts.wt. of nylon 46 resin with (B) 5-100 pts.wt. of an aliphatic polyamide resin having methylene groups and amide groups in the polymer main chain at a number ratio (methylene/amide) of >=6 (e.g. nylon 12, nylon 11, nylon 612 or nylon 66/636 copolymer), (C) 2-100 pts.wt. of a brominated polystyrene, (D) 1-50 pts.wt. of a flame-retarding assistant (preferably antimony trioxide) and (E) 5-200 pts.wt. of glass fiber.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a resin composition that can be used for surface-mountable electronic components, and more specifically, a resin composition that exhibits excellent water absorption properties, dimensional properties, and reflow solderability. The present invention relates to a glass Im fiber-reinforced polytetramethylene adipamide (nylon 46) lit resin composition, and an electronic component obtained by surface mounting using this resin composition.

[Prior art] In the field of electronic components, with the recent miniaturization and higher performance of electrical appliances, and with the aim of improving productivity, the mounting density of components is increasing as a method of mounting various electronic components on boards. The highly efficient surface mount method (SMT method) is becoming widespread.

Therefore, in response to this method, resin materials for electronic parts are also required to have improved mechanical strength and fluidity during molding as they become smaller and thinner. Furthermore, due to the surface mounting method, soldering by heating in a beam flow furnace means that the electronic component material such as the connector is heated from the top, and the temperature is more severe than in the conventional mounting method. be exposed to conditions. As a result, resin materials for electronic components are required to have improved heat resistance. For example, conventional materials such as polyamide resins such as nylon 6 resin and nylon 66 resin, and polyester resins such as polyethylene terephthalate and polybutylene terephthalate Heat resistance is insufficient.

Therefore, the use of polyphenylene sulfide resin, aromatic polyamide resin, etc. as resin materials for surface-mountable electronic components is being considered, but although these resins have excellent heat resistance, they have drawbacks in the mechanical properties, flow properties, etc. mentioned above. Therefore, there are major restrictions on industrial use. Thus, there is a strong demand in this field for resin materials that have excellent mechanical properties, flow properties, and heat resistance and can be used as base materials for surface-mountable electronic components.

Nylon 46 resin is attracting attention as a material that can meet this demand. Nylon 46 resin is a resin obtained from tetramethylene diamine or its functional derivative and adipic acid or its functional derivative, and has excellent durability.
It also has excellent mechanical properties such as tensile strength and bending strength, and flow properties, so it is considered to have great value in terms of use as a useful engineering plastic. As materials for electronic components, the use of compositions with flame retardancy imparted by halogenated compounds and metal oxides, including systems reinforced with glass fibers, is being proposed (Japanese Patent Laid-Open No. 61-1
88463, 61-188872, 63-51
456, 63-118368, 63-12807
3, 63-139942, 63-161056
, 63-195907, 63-195909
, 63-223060, 63-317552,
Publication No. 64-11158, etc.).

However, this nylon 461! I fat is nylon 611
Since it has a higher proportion of amide groups than ordinary polyamide resins such as 1 resin and nylon 66 resin, it has the disadvantage that its water absorption rate is higher than those of them. This means that while nylon 46 resin has better heat resistance and mechanical properties than ordinary polyamide resins in the dry state immediately after molding, in actual use it has higher water absorption than ordinary polyamide resins, resulting in poor heat resistance. , the mechanical properties will be greatly reduced, and in some cases, the superiority of nylon 46 resin will be lost. Furthermore, the higher the water absorption rate, the greater the dimensional change. Although nylon 46 resin generally has a smaller dimensional change rate per water absorption rate than polyamide resin, due to its high water absorption rate, its dimensional accuracy is not necessarily at a satisfactory level, and it cannot be applied to parts that require high accuracy. Needs improvement. Furthermore, when mounting on a board using the surface mounting method using the above-mentioned adhesive flow furnace, although electronic components made of nylon 46 resin exhibit their heat resistance in a dry state, if water is absorbed, the surface of the component may develop blisters. If damage occurs, the value of the component will be significantly reduced, and the range of conditions for the surface mount method will become narrower. That is, nylon 461f
Electronic components made of IJ resin are inferior in dimensional characteristics and reflow solderability due to the water-absorbing nature of nylon 46 resin, making it difficult to utilize the excellent heat resistance of this resin as a material for surface-mountable electronic components. This has become a major obstacle.

[Object of the invention] The present invention was made against the background of the above-mentioned circumstances, and
The purpose is to use nylon 46 as a surface-mountable electronic component material that exhibits excellent water absorption properties, dimensional properties, and reflow solderability.
The object of the present invention is to obtain a resin composition and thereby provide a surface-mountable electronic component.

U Constituent of the invention
As a result of intensive research to improve the water absorption characteristics, dimensional characteristics, and reflow resistance of 6 resin, we found that a composition containing a specific amount of a specific polymer in flame-retardant glass fiber reinforced nylon 46 resin met the above objectives. The inventors discovered that it was possible to provide surface-mountable electronic components and arrived at the present invention.

That is, the resin composition of the present invention contains (^) per 100 parts by weight of nylon 46 resin, [
B) 5 to 100 parts by weight of an aliphatic polyamide resin in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 6 or more, (C) 2 to 100 parts by weight of brominated polystyrene, (D) 1 to B combustion aid 50 parts by weight, and (E) 5 to 200 parts by weight of glass fibers, and a surface-mountable electronic component made of the resin composition.

The present invention will be explained.

The surface-mount compatible electronic component of the present invention refers to an electronic component that is soldered onto a board using a surface-mount method.
Here, the surface mount method is a method of mounting electronic components on a wiring board by passing the leads of the electronic components through the through holes of the board and directly soldering (flow soldering) to the surface opposite to the surface on which the electronic components are mounted. In contrast to conventional insertion mounting (or wave soldering), electronic components are placed on top of solder printed on a wiring board, and the entire board is passed through a heating furnace called a flow furnace to melt the solder. This is a method of fixing.

This surface mounting method can bring about various advantages such as increasing packaging density, making it possible to mount both the front and back sides, and reducing costs through increased efficiency. With the trend toward higher functionality and lower prices, soldering is becoming the mainstream method.
Its application fields include camera-integrated VTRs, desks, cameras, watches, LCD TVs, electronic games, and consumer electronic devices such as handheld computers, computers, office computers, workstations, personal computers, peripheral devices, end devices, measuring instruments, etc. It has spread to industrial electronic equipment and even spacecraft equipment.

Methods for heating the board in a reflow oven for surface mounting include the heat conduction method, in which the board is placed on a heat-resistant belt that moves over a heater, and the latent heat generated during aggregation of a fluorine-based liquid with a boiling point of approximately 220°C. The VPS method used, the hot air convection heat transfer method in which hot air is forced to circulate through the board, the far infrared method in which far infrared rays are used to heat the board from the top or both sides, and the heating by hot air and far infrared rays. There are methods that use a combination of heating, but for reasons such as running costs, far-infrared radiation methods and hot air convection heat transfer methods are often adopted. Unlike the conventional insertion mounting method, these heating methods also heat the mounted components to the solder melting temperature, creating extremely harsh conditions for the resin materials used in electronic components.

Specific examples of these surface-mountable electronic components include connectors, switches, volumes, capacitors, ICs,
Examples include parts made of resin such as bodies and cases of parts such as relays, resistors, and LEDs.The present invention is directed to resin electronic parts mounted on a board by such a surface mounting method.

Nylon 46@fat, component (A), used in the present invention is mainly a polyamide obtained by a condensation reaction using adipic acid or a functional derivative thereof as an acid component and tetramethylene diamine or a functional derivative thereof as an amine component. However, a part of the adipic acid component or tetramethylene diamine component may be replaced with another copolymer component.

A preferred embodiment of the nylon 46 resin is disclosed in JP-A-56-149.
430 and JP-A-56-149431.

The nylon 46 resin used in the present invention has an intrinsic viscosity of 0.90 to 1.90, more preferably 1.10 to 1, when measured at 35°C using m-cresol in electronic components.
．． It is desirable that it be in the range of 50.

When using nylon 46 resin with an intrinsic viscosity exceeding 1.90, the fluidity during molding of electronic parts is poor, and the resulting electronic parts not only lose their glossy appearance but also deteriorate their mechanical and thermal properties. This is not appropriate because the variation becomes large.

On the other hand, if the intrinsic viscosity is lower than 0.90, the mechanical strength of the electronic component will be reduced.

The ratio of the number of methylene groups to the number of amide groups in the polymer main chain of component (B) used in the present invention is 6 or more, and the aliphatic polyamides include nylon 11, nylon 12, nylon 69, nylon 610, nylon 611, and nylon 61.
2. Nylon 613, nylon 636, nylon 644
, nylon 1212, etc. These polyamides can be easily obtained from the condensation polymerization of the corresponding diamines and dicarboxylic acids, the condensation polymerization of the corresponding aminocarboxylic acids, or the ring-opening polymerization of the corresponding cyclic lactams. Among these aliphatic polyamides, nylon 11 and nylon 12 may be copolymerized with other amines or ester-forming compounds within a range.
, nylon 612, nylon 636, nylon 66/
636 copolymer is preferred. However, aliphatic polyamides in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 5 or less are not effective in reducing the water absorption dimensional change rate or improving flow solderability of nylon 46, making them unsuitable polymers. .

The brominated polystyrene represented by the following formula (I> (in the above formula (I>), p is an integer of 1 to 5, and n is an integer of 2 or more) of the fc) component used in the present invention is It is produced by polymerizing styrene or by brominating polystyrene.Furthermore, formula (I) can be used even if other vinyl compounds are copolymerized.As the vinyl compound in this case, Examples include styrene and α-methylstyrene.

The degree of polymerization of the brominated polystyrene represented by formula (I) is not particularly limited, but the weight average molecular weight is s, oo.

~1,000,000 is preferably used. −
Brominated polystyrene represented by the formula (I>) is blended for the purpose of making the nylon 46 resin resin composition of the present invention and surface-mountable electronic components flame retardant, and the blending amount is nylon 46.
The amount is 2 to 100 parts by weight per 100 parts by weight of 6 resin.

If the blending amount is less than 2 parts by weight, the flammability effect will not be sufficient, and 1
If the amount exceeds 0.00 parts by weight, the mechanical properties and thermal properties of the resulting composition and electronic parts will be impaired, which is not preferable.

The combustion aid fD) used in the present invention is made of nylon 46 due to the synergistic effect with the brominated polystyrene fc) component.
It works to improve the flame retardancy of resin resin compositions and surface-mountable electronic components. Examples of such compounds include compounds of metals in group Va of the periodic table and metal oxides such as boron oxide, zirconium oxide, iron oxide, and zinc oxide.In particular, compounds of metals in group Va of the periodic table include Antimony compounds are preferred; examples of antimony compounds include antimony dioxide, antimony pentoxide, sodium antimonate, and antimony trioxide is particularly preferably used. Furthermore, these combustion aids may be used alone or in combination of two or more kinds.

The blending amount of these combustion aids is 1 metal atom such as antimony for every 2 to 5 bromine atoms of the brominated polystyrene component (fc).
The appropriate ratio is .

The glass fiber used in the present invention as component (E) is blended for the purpose of increasing the mechanical strength and heat resistance of resin compositions and electronic components, and may be generally used for reinforcing resins. There are no particular limitations. For example, long fiber type (
It can be selected from among fibers such as roving), short fibrous chopped strands, and milled fibers. Crow 11 again! Ii fibers contain sizing agents (e.g. polyvinyl acetate, polyester sizing agents, etc.), coupling agents (e.g. silane compounds, boron compounds, titanium compounds, etc.),
It may also be treated with other surface treatment agents. Usually, long fiber type glass fibers are used by being cut to a desired length before or after blending with a resin, and this mode of use is also useful in the present invention.

The amount of glass fiber blended is preferably 5 to 200 parts by weight per 100 parts by weight of nylon 46 resin.
If the amount is less than 1 part by weight, the mechanical strength and heat resistance of the electronic component will not be sufficient, and if it exceeds 200 parts by weight, the fluidity during molding of electronic components etc. will be significantly poor, resulting in poor appearance. Molded products cannot be obtained, and the strength reaches saturation, which is not preferable.

The glass fiber length is preferably such that the main portion of the glass fiber has a length of 0.2% or more in the composition or electronic component.

Is an electronic component made of a composition containing nylon 46 resin, brominated polystyrene, a flame retardant aid, and glass fiber an excellent electronic component that has sufficient heat resistance to withstand surface mounting in a dry state? In actual use, nylon 4
6. Resin absorbs moisture from the atmosphere, which not only causes dimensional changes, but also causes damage called blistering on the surface of electronic components when surface mounting is performed in that state, even under temperature conditions that would not cause problems in dry conditions. They start to appear more often. However, in an electronic component made of a composition further containing an aliphatic polyamide resin in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 6 or less,
The water absorption of electronic components is reduced, dimensional changes are suppressed, and damage caused by blisters is less likely to occur. This phenomenon called blistering is generally explained as occurring when moisture that has entered the inside of an electronic component evaporates internally due to heating, and it is easy to infer that this phenomenon can be suppressed by reducing the water absorption of electronic components. . However, in electronic components made of compositions containing polyamide resins with low water absorption, such as non-grade aromatic nylon resins, aliphatic compounds with a ratio of methylene groups to amide groups in the main chain of the polymer of 6 or more are used. An unexpected result was obtained in that although the water absorbency decreased as in the case of blending polyamide resin, the occurrence of blisters during surface mounting could not be suppressed. In addition, nylon 6 resin and nylon 66 resin in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 5 do not improve the water absorption characteristics or suppress the blistering phenomenon of electronic components made of compositions containing them. do not have. In other words, it is possible to simultaneously improve these water absorption characteristics, dimensional characteristics, and the occurrence of blistering when an aliphatic polyamide resin in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 6 or more is blended. We found that this is a unique behavior seen only in humans.

The amount of the aliphatic polyamide resin used in the present invention, which is component [8] and has a ratio of the number of methylene groups to the number of amide groups in the polymer main chain of 6 or more, is 5 to 100 parts by weight per 100 parts by weight of nylon 46tM resin. . When the amount is less than 5 parts by weight, the effect of suppressing the blistering phenomenon in electronic parts made of the composition is not sufficient, and when it is more than 100 parts by weight, the heat resistance and mechanical strength of the molded product are greatly reduced. Put it away.

Nylon 46 constituting the surface-mountable electronic component of the present invention
If necessary, pigments and other compounding agents may be added to the resin composition in the desired amount. Such additives include fillers such as aramid fibers, carbon fibers, steel fibers,
Fibrous materials such as ceramic fibers, potassium titanate whiskers, and boron whiskers; powdered materials such as kaolin, clay, wollastonite, talc, mica, calcium carbonate, barium sulfate, glass beads, and glass flakes;
Examples include granular or plate-shaped inorganic fillers.

These fillers are usually blended as reinforcing materials, surface modifiers, or for the purpose of modifying electrical, thermal properties, etc., or they are used to minimize the effect of blending and to reduce the original composition of the composition by over-blending. It should be blended within a range that does not impair the excellent properties and molding advantages.

Other flame retardants, such as brominated polyphenylene ether, brominated epoxy, brominated bisphenol-A-diglycidyl ether and its oligomers, polycarbonate oligomers produced from brominated bisphenol-A, brominated biphenyl ether, brominated Halogen-containing compounds such as cyphthalimide compounds and dimers of chlorinated hexapentadiene; phosphorus compounds such as red phosphorus and triphenyl phosphate; phosphorus-nitrogen compounds such as phosphonic acid amide; melamine, melam, melem, melon, cyanuric acids, triazine compounds such as melamine cyanurate; aluminum hydroxide, magnesium hydroxide, Tone Night,
It is also possible to use metal hydroxides such as gypsum dihydrate in combination.

Furthermore, copper compounds such as copper iodide,
Antioxidants or heat stabilizers such as hindered phenol compounds, aromatic amine compounds, organic phosphorus compounds, and sulfur compounds may also be added. In addition, various epoxy compounds, oxazoline compounds, etc. may be added for the purpose of improving melt viscosity stability and hydrolysis resistance. Examples of epoxy compounds include those obtained by reacting bisphenol-A and epichlorohydrin. Preferred are bisphenol-A type epoxy compounds, aliphatic glycidyl ethers obtained from the reaction of various glycols or glycerol with epichlorohydrin, novolak type epoxy compounds, aromatic or aliphatic carboxylic acid type epoxy compounds, alicyclic compound type epoxy compounds, etc. Oxazoline compounds include aromatic or aliphatic bisoxazolines, especially 2,2°-
Bis(2-oxazoline) and 2,2°-m-phenylenebis(2-oxazoline) are preferred.

Other stabilizers, colorants, lubricants, ultraviolet absorbers, and LTR antistatic agents may also be added.

Furthermore, in small proportions other thermoplastic resins, such as other polyamide resins, other polyester resins, polyphenylene sulfide resins, polyphenylene ether resins, polycarbonate resins, phenoxy resins, polyethylene and its copolymers, polypropylene and its copolymers , polystyrene and its copolymers, acrylic resins and acrylic copolymers, polyamide elastomers, polyester elastomers, etc.; thermosetting resins such as phenol resins, melamine resins, unsaturated polyester resins, silicone resins, etc. may be blended. .

Any blending method can be used to obtain the nylon 46 resin composition for molding the surface-mountable electronic component of the present invention.

Generally, it is preferable to disperse these ingredients more uniformly, and there are methods in which all or part of them are mixed simultaneously or separately in a mixing machine such as a blender, kneader, roll, or extruder for homogenization, or in a mixing part. A method can be used in which a part of the components are mixed simultaneously or separately using, for example, a blender, kneader, roll, extruder, etc., and then the remaining components are mixed and homogenized using these mixers or extruders. Furthermore, there is a method in which a pre-triblended composition is melt-kneaded in an extruder without heating to homogenize it, extruded into a wire shape, and then cut into a desired length and granulated.

Molding of electronic parts using the molding pellet thus obtained can be performed using a normal injection molding machine. In this case, it is often necessary to supply the molding pellet to the hopper of the molding machine in a sufficiently dry state.

[Example] The present invention will be explained in detail with reference to Examples below.

Nylon 46 resin (rsTANYL) with an intrinsic viscosity of 1.40 was dried at 110°C under a reduced pressure of 10 Torr for 12 hours.
Nylon 12 resin (Diamide
J Toshi ■), molecular weight 80.000, melting point 160°
C nylon 66/636 copolymer (rp old^DIT
2054j manufactured by UNICHEHA in the Netherlands), nylon 6 resin with an intrinsic viscosity of 1.30 (manufactured by Yuto), non-grade aromatic nylon resin (TR0GAHID TJ manufactured by Dynalit Nobel in West Germany), brominated polystyrene (Pyrocheck 68- PR, made by Nissan Ferro Organic Chemical Co., Ltd.), antimony trioxide (“Patricks C” made by Nippon Seiko Co., Ltd.) and glass fiber chopped strands (
Nippon Electric Glass Co., Ltd.) were mixed uniformly in a tumbler in advance in the proportions shown in Table 1, and then heated to a cylinder temperature of 320°C while being evacuated using a vented twin-screw extruder with screw diameters of 44 mm. The mixture was melt-kneaded at a screw rotation speed of 150 rpm and a discharge rate of 40 kg/h, and the thread discharged from the die was cooled and cut to obtain a pellet for molding.

Using the pellet made in the above method, the cylinder temperature was 300°C, the mold temperature was 120°C, the injection pressure was 800kg/aa, the cooling time was 15 seconds, and the total temperature was 120°C. Molded articles for each characteristic measurement were molded under conditions of a molding cycle of 40 seconds.

Each characteristic was measured using these molded products. Before measurement, molded products should be heated at 23°C, relative humidity 5, according to JIS 7100.
Conditioning was performed in a 0% atmosphere for 88 hours.

In addition, various characteristics in the examples were measured by the following methods.

(1) II Mechanical strength: Impact test...ASTHD256 (Izotsu, notched, thickness 3.2cm) (2) Deflection temperature under load: Based on ASTHhoeAa. (Load 18.6kg/c
la) (3) Water absorption properties: Calculated from the weight increase after being left in an atmosphere of 80°C and 95% relative humidity for 24 hours. (Molded product thickness: 1.5 mm) (4) Dimensional characteristics: Calculated from dimensional changes after being left in an atmosphere of 80°C and 95% relative humidity for 24 hours, (molded product: 100 nlx in flow direction)
(5) Combustibility (2) Method specified by U.S. Antarliter Laboratory, Inc. (U.
Evaluated by L94). (Thickness: 0.8 m+) (6) Intrinsic viscosity: Measured at 35°C using an Ostwald viscosity tube using m-cresol as a solvent.

These results are shown in Table-1. A nylon 46 resin composition reinforced with 1m glass fiber and flame-retardant with brominated polystyrene and antimony trioxide exhibits excellent impact strength and deflection temperature under load, but has the drawback of high water absorption and accompanying large dimensional changes. However, when this composition is further blended with nylon 12 resin, nylon 11 resin, or nylon 66/636 copolymer, the water absorption rate and dimensional change rate are reduced (Examples 1 to 5). ). Furthermore, these compositions maintain the high deflection temperature under load that is characteristic of nylon 46 resin, and also have sufficient impact strength to be used as connectors (Examples 1 to 4). When other polyamide resins are blended, nylon 6 resin shows no noticeable improvement in water absorption and dimensional change rate, but amorphous aromatic nylon resin shows nylon 12V! The water absorption rate is reduced in the same way as with J fat etc. (Comparative Examples 3 to 5).

As an example of a connector manufactured electronic component, a pellet with the composition shown in Table 1 prepared by the above method was used in an injection molding machine with an injection capacity of 1 ounce at a cylinder temperature of 300°C and a mold temperature of 120'C1 injection pressure. Under the conditions of 1.000 kg/cd, cooling time of 5 seconds, and total molding cycle of 20 seconds, the dimensions 14 x 7 x 4 (M
I) A 6-hole box-type connector with an average wall thickness of 0.5 mm was molded.

These connectors were conditioned for 1 hour at 80°C and 195% body humidity to promote water absorption and obtain water-absorbed connectors.

Reflow properties of connector molded products Reflow solderability tests of various connector molded products obtained by the above method were conducted using a simple tabletop reflow oven (manufactured by Toyodenso Co., Ltd.). The heating temperature pattern is set to preheat at 150°C for 40 seconds, then heat at the desired temperature for 20 seconds, and for reflow soldering, measure the surface temperature of the board with an infrared sensing thermometer. It was determined by Reflow soldering resistance was evaluated based on the frequency of blisters occurring on the surface of the connector molded product after heating in a reflow oven.

The results are shown in Table-1. Flame-retardant nylon 46 resin reinforced with glass fibers exhibits excellent heat resistance in the dry state, and its surface condition remains unchanged even after passing through a reflow oven (Comparative Example 1). However, when the connector is actually used, When the connector is exposed to water, it absorbs water, and the absorbed nylon 461ij resin causes surface damage called blistering, which can be seen on almost all connectors at 250°C ( Comparative example 1).

However, flame retardant nylon 46 reinforced with glass fiber
Connectors with compositions that contain nylon 12 resin, nylon 11 resin, or nylon 667636 copolymer in addition to 1!1 resin absorb less water after humidity conditioning under the same conditions compared to connectors that do not contain nylon 12 resin, nylon 11 resin, or nylon 667636 copolymer. No blistering occurs at all until about 270°C (Examples 1 to 5)
). This shows that the reflow resistance of connectors made of compositions containing nylon 12 resin, nylon 11 resin, and nylon 66/'636 copolymer is significantly improved. Furthermore, when a similar test was conducted using a connector with a composition containing a non-quality aromatic nylon resin,
As in the case of nylon 12 resin, the water absorption rate of connectors with a composition containing these resins is reduced, but the occurrence of blisters after passing through a flow furnace cannot be suppressed (Comparative Examples 2 to 3) ). In other words, nylon 12 resin, nylon 11m resin, and nylon 6 can suppress the blistering phenomenon.
This is a phenomenon that occurs specifically in connectors made of a composition containing a polyamide resin of the 6/636 copolymer, and the effect of improving reflow resistance appears only by a combination of these compositions.

Claims (1)

[Claims] 1. (A) per 100 parts by weight of nylon 46 resin, (B)
5 to 100 parts by weight of an aliphatic polyamide resin in which the ratio of the number of methylene groups to the number of amide groups in the polymer main chain is 6 or more, (C) 2 to 100 parts by weight of brominated polystyrene, (D) 1 to 50 parts by weight of a flame retardant aid. and (E) 5 to 200 parts by weight of glass fiber. 2. The resin composition according to claim 1, wherein component (B) is nylon 12. 3. The resin composition according to claim 1, wherein the component (B) is nylon 11. 4. The resin composition according to claim 1, wherein component (B) is nylon 612. 5. The resin composition according to claim 1, wherein component (B) is a nylon 66/636 copolymer. 6. A surface-mountable electronic component comprising the resin composition according to claim 1.