JP2003321606A - Polyamide resin composition for insert mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyamide resin composition which is molded at a relatively low temperature, has excellent impact resistance, hardly causes warpage in a molding and is suitable for an insert mold for an electronic part, etc. <P>SOLUTION: The polyamide resin composition comprises 100 parts wt. of the total of 45-85 parts wt. of a polyamide resin having a melt peak temperature (T<SB>pm</SB>) of ≥140°C and <210°C, 1-47.5 parts wt. of a scaly filler and 1-47.5 parts wt. of a fibrous filler and has a melt flow rate (MFR) of ≥100 g/10 minutes (230°C, 21.18 N). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide resin composition suitable for insert molding of electronic parts and the like.

[0002]

2. Description of the Related Art In order to impart impact resistance and designability to electronic parts, a method of attaching a protective panel to the electronic parts with an adhesive and packaging it has been conventionally used. However, in such a method, the number of manufacturing steps increases,
A method that can be packaged in a simpler way is desired.

By the way, as a method of sealing an electronic component or a printed circuit board on which the electronic component is mounted, a method of sealing using a thermosetting resin has been generally adopted.
However, since the thermosetting resin is cured by a cross-linking reaction, various additives are added, the handling is complicated, and the resin has poor storage stability. Furthermore, since it takes a relatively long time from the injection of the thermosetting resin into the mold cavity to the curing by the chemical crosslinking reaction, there is a problem that the productivity cannot be improved.

In Japanese Patent Laid-Open No. 2000-133665,
In order to solve such a problem, a method of sealing with a polyamide resin, which is a thermoplastic resin, has been proposed.

[0005]

However, when an electronic component or the like is sealed and packaged with such a resin, there is a problem that the impact resistance is insufficient.

As a method for improving the impact resistance of the resin, a method of blending glass fiber can be considered. However,
When a resin containing glass fiber is used, the linear expansion coefficient may be anisotropic, and the molded product may be warped.

The object of the present invention is a polyamide resin composition suitable for insert molding of electronic parts, which can be molded at a relatively low temperature, has excellent impact resistance, and is unlikely to cause warpage in a molded product. To provide.

[0008]

SUMMARY OF THE INVENTION The insert mode of the present invention.
The polyamide resin composition for cold welding has a melting peak temperature.
(T _pm) Is 140 ° C. or more and less than 210 ° C.
Resin 50 to 80 parts by weight and scale-like filler 1 to 47.5 parts by weight
And 1 to 47.5 parts by weight of fibrous filler, respectively.
The total melt flow rate is 100 parts by weight.
Rate (MFR) is 100g / 10 minutes or more (230 ℃,
21.18 N).

By using the polyamide resin composition for insert molding of the present invention, electronic parts and the like can be sealed at a relatively low temperature and can be packaged at the same time. Therefore, sealing and packaging can be performed without damaging the electronic components and the like. Further, when a resin containing only a fibrous filler such as glass fiber is used, the linear expansion coefficient in the injection vertical direction (TD: Transverse direction) becomes large and warpage easily occurs, but the polyamide resin composition of the present invention If a product is used, the linear expansion coefficient in the injection vertical direction (TD) during molding becomes sufficiently small, so that the occurrence of warpage during molding can be prevented. Further, good impact resistance can be imparted by using the polyamide resin composition of the present invention.

The melting peak temperature (T _pm ) of the polyamide resin used in the present invention is 140 ° C. or higher and lower than 210 ° C. The melting peak temperature (T _pm ) is measured by the differential scanning calorimeter (DS).
In C), the melting temperature is measured according to JIS K-7121. If the melting peak temperatures (T _pm ) appear more than one independently, then all peaks must be within this range. If the melting peak temperature (T _pm ) is less than 140 ° C, sufficient impact strength may not be obtained. On the other hand, when the temperature is 210 ° C. or higher, it is necessary to raise the molding temperature in order to obtain a good molded product, which may impair the operation of electronic components and the like.

The number average molecular weight of the polyamide resin used in the present invention is preferably less than 15,000.
The number average molecular weight is a polystyrene equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC). When the number average molecular weight is 15,000 or more, it is necessary to raise the molding temperature, which may impair the operation of electronic parts and the like. The lower limit of the number average molecular weight of the polyamide resin is not particularly limited, but it is generally preferably 1000 or more.

The polyamide resin used in the present invention includes, for example, a condensate of a dicarboxylic acid and a diamine, a polycondensate of an aminocarboxylic acid, a ring-opening polymer of a cyclic lactam, and specifically, nylon 6 , Nylon 6
6, nylon 610, nylon 612, nylon 11,
Aliphatic polyamides such as nylon 12, nylon 46, nylon containing polymerized fatty acid, poly (hexamethylene terephthalamide), poly (hexamethylene isophthalamide), aliphatic-aromatic polyamides such as nylon MXD6, and copolymers thereof. Mention may be made of mixtures. Also, block copolymer type and random copolymer type polyamide elastomers in which the above polyamide resin is used as a hard segment and polyols such as polytetramethylene glycol, polypropylene glycol, aliphatic polyester diol and polyoxyalkylene glycol are used as a soft segment. Can be used.

Examples of the scale-like filler used in the present invention include glass flakes, plate silicates and boron nitride. The glass flakes may be used in the form of granules to which glass flakes are bound. Examples of such glass flake-bonded granules include Microglass Flaker REFG-103 and REFG-302 manufactured by Nippon Sheet Glass Co., Ltd.

The material of the glass flakes is not particularly limited, and non-alkali glass (E glass) and alkali-containing glass (C glass) can be used.
The glass flakes may be surface-treated.
Examples of the surface treatment agent include coupling agents such as aminosilane coupling agents.

The average particle size of the glass flakes is 10-40.
It is preferably 00 μm, more preferably 10
Is about 800 μm. The average thickness is preferably 1 to 6 μm.

Examples of the plate silicate include mica,
Examples include talc, kaolin, clay and sericite. The plate silicate may be surface-treated with a coupling agent or the like. Examples of the coupling agent include isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, and epoxy compounds.

The average particle size of the plate silicate is 1 to 3000.
μm is preferable, and more preferably 10 to 2
It is 00 μm. The fibrous filler used in the present invention may be inorganic or organic. Examples of the inorganic fibrous filler include glass fibers, whiskers, wollastonite, alumina fibers, ceramic fibers and the like.

The material of the glass fiber is not particularly limited, and examples thereof include non-alkali glass (E glass) and alkali-containing glass (C glass). The glass fiber may be surface-treated. Examples of the surface treatment agent include coupling agents such as aminosilane coupling agents.

The average fiber length of the glass fibers is 0.1-10.
mm is preferable, and more preferably 0.3 to
It is 3 mm. The average fiber diameter is preferably 4 to 20 μm.

Examples of whiskers include potassium titanate, aluminum borate, calcium carbonate, zinc oxide and the like. Examples of wollastonite include silicon carbide. Examples of the organic fibrous filler include aramid fibers such as aromatic polyamide.

The polyamide resin composition of the present invention contains 45 to 85 parts by weight of polyamide resin and 1 to 4 of scale-like fillers.
7.5 parts by weight and 1 to 47.5 parts by weight of the fibrous filler are contained so that the total amount becomes 100 parts by weight. A more preferable compounding amount of the scale-like filler is 10 to 45 parts by weight.
A more preferable compounding amount of the fibrous filler is 5 to 40 parts by weight.

If the blending amount of the scale-like filler is small in the above blending ratio, the linear expansion coefficient in the injection vertical direction (TD) does not become so small that warpage may occur. On the other hand, if the amount of the scale-like filler is too large, the amount of the fibrous filler is relatively decreased, so that the impact resistance is impaired.

If the amount of the fibrous filler compounded is small in the above compounding ratio, the impact resistance becomes insufficient. Further, if the blending amount of the fibrous filler is too large, the blending amount of the scaly filler relatively decreases, which may cause warpage.

The polyamide resin composition of the present invention has a melt flow rate (MFR) of 230 ° C. and a load of 2
It should be 100 g / 10 minutes or more under the measurement condition of 1.18 N. Melt flow rate (MFR) is JIS
It is a value measured according to K-7210. If the melt flow rate is lower than this value, it is necessary to increase the injection pressure in order to obtain a good molded product at a low temperature, which may impair the operation of the insert-molded electronic component or the like. When the melt flow rate exceeds about 1500 g / 10 minutes, the measurement becomes difficult. Therefore, in the present invention, a melt flow rate lower than this is usually used.

A coloring pigment may be added to the polyamide resin composition of the present invention, if necessary.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples.

(Example 1) Polyamide resin A (manufactured by Nippon Paint Co., T _pm1 = 180 ° C., T _pm2 = 190 ° C., Mn =
7000) 51 parts by weight, commercially available glass flake-bound granules B (average particle size 600 μm, average thickness 5 μm) 36 parts by weight, and commercially available glass fibers C (average fiber length 3 mm, average fiber diameter 13 μm) 13 parts by weight. Then, 2 parts by weight of commercially available titanium oxide was uniformly mixed in advance, and then melt-kneaded with a twin-screw extruder. At this time, the extruder barrel temperature and the screw rotation speed were adjusted so that the molten resin temperature was 230 ° C. After the obtained resin composition was pelletized, a mold prepared to have a sample size was injection molded at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C. to prepare a sample.

(Example 2) A polyamide resin composition was prepared in the same manner as in Example 1 except that 66 parts by weight of polyamide resin A, 21 parts by weight of glass flake-bonded granules B, and 13 parts by weight of glass fiber C were used to prepare a sample. It was created. Melt kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

(Example 3) A polyamide resin composition was prepared in the same manner as in Example 1 except that 80 parts by weight of polyamide resin A, 12 parts by weight of glass flake-bonded granules B and 8 parts by weight of glass fiber C were used. It was created. The melt-kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Example 4 Instead of the glass flake-bonded granules B, commercially available glass flakes D (average particle size 160 μm) were used.
m, average thickness 5 μm) except that a polyamide resin composition was prepared in the same manner as in Example 1 to prepare a sample. The melt-kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Example 5 A polyamide resin composition was prepared in the same manner as in Example 1 except that commercially available mica E (average particle size 150 μm) was used in place of the glass flake-bonded granules B, and samples were prepared. . Melt-kneading of resin is performed at a barrel temperature of 230 ° C., a cylinder temperature of 240 ° C., and a mold temperature of 8
Injection molded at 0 ° C.

(Example 6) Instead of the glass flake-bonded granules B, commercially available glass flakes D (average particle size 160 μm) were used.
m, average thickness 5 μm) except that the polyamide resin composition was prepared in the same manner as in Example 2 to prepare a sample. The melt-kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Example 7 A polyamide resin composition was prepared in the same manner as in Example 2 except that commercially available mica E (average particle size 150 μm) was used in place of the glass flake-bonded granules B, and samples were prepared. . Melt-kneading of resin is performed at a barrel temperature of 230 ° C., a cylinder temperature of 240 ° C., and a mold temperature of 8
Injection molded at 0 ° C.

Example 8 Instead of the glass flake-bonded granules B, commercially available glass flakes D (average particle size 160 μm) were used.
m, average thickness 5 μm) except that the polyamide resin composition was prepared in the same manner as in Example 3 to prepare a sample. Melt kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Example 9 A polyamide resin composition was prepared in the same manner as in Example 3 except that commercially available mica E (average particle size 150 μm) was used in place of the glass flake-bonded granules B, and samples were prepared. . Melt-kneading of resin is performed at a barrel temperature of 230 ° C., a cylinder temperature of 240 ° C., and a mold temperature of 8
Injection molded at 0 ° C.

Example 10 Instead of the glass fiber C, commercially available potassium titanate whisker F (average fiber length 10 to 2) was used.
0 μm) was used, and a polyamide resin composition was prepared in the same manner as in Example 1 to prepare a sample. Melt-kneading of resin is performed at a barrel temperature of 230 ° C. and a cylinder temperature of 240 ° C.
Injection molding was carried out at a mold temperature of 80 ° C.

Example 11 A polyamide resin composition was prepared in the same manner as in Example 1 except that commercially available wollastonite G (average fiber length: 5 μm) was used in place of the glass fiber C, and a sample was prepared. . Melt kneading of resin, barrel temperature 2
Perform at 30 ℃, cylinder temperature 240 ℃, mold temperature 80
Injection molded at ° C.

Example 12 Instead of the polyamide resin A, a polyamide resin H (manufactured by Nippon Paint Co., Ltd., T _pm1 = 17) was used.
A polyamide resin composition was prepared in the same manner as in Example 1 except that 0 ° C., T _pm2 = 180 ° C., Mn = 12000) was used, and a sample was prepared. Melt kneading of resin, barrel temperature 2
Perform at 10 ℃, cylinder temperature 240 ℃, mold temperature 80
Injection molded at ° C.

Example 13 A polyamide resin composition was prepared in the same manner as in Example 2 except that the polyamide resin H was used instead of the polyamide resin A, and a sample was prepared. Melt kneading of the resin was performed at a barrel temperature of 210 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Example 14 A polyamide resin composition was prepared in the same manner as in Example 3 except that the polyamide resin H was used in place of the polyamide resin A to prepare a sample. Melt kneading of the resin was performed at a barrel temperature of 210 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

Comparative Example 1 A polyamide resin composition was prepared in the same manner as in Example 1 except that 51 parts by weight of polyamide resin A, 49 parts by weight of glass fiber C and 2 parts by weight of titanium oxide were used to prepare a sample. did. The melt-kneading of the resin was performed at a barrel temperature of 230 ° C., injection molding was performed at a cylinder temperature of 240 ° C. and a mold temperature of 80 ° C.

(Comparative Example 2) A polyamide resin composition was prepared in the same manner as in Example 1 except that 51 parts by weight of polyamide resin A, 49 parts by weight of glass flake-bonded granules B and 2 parts by weight of titanium oxide were used. It was created. Melt-kneading of resin is performed at a barrel temperature of 230 ° C. and a cylinder temperature of 2
Injection molding was performed at 40 ° C and a mold temperature of 80 ° C.

Comparative Example 3 Instead of the polyamide resin A, polyamide resin I (manufactured by Nippon Paint Co., Ltd., T _pm1 = 210) was used.
C., T _pm2 = 220 ° C., Mn = 12000) except that a polyamide resin composition was prepared and samples were prepared in the same manner as in Example 1. Melt kneading of resin, barrel temperature 2
Perform at 50 ℃, cylinder temperature 260 ℃, mold temperature 80
Injection molded at ° C.

Comparative Example 4 Polyamide resin J (manufactured by Nippon Paint Co., T _pm1 = 120) instead of polyamide resin A was used.
C., T _pm2 = 130 ° C., Mn = 10000) except that a polyamide resin composition was prepared in the same manner as in Example 1 to prepare a sample. Melt kneading of resin, barrel temperature 1
Perform at 50 ℃, cylinder temperature 180 ℃, mold temperature 80
Injection molded at ° C.

[Evaluation of Polyamide Resin Composition] Example 1
14 to 14 and the melt flow rates of the polyamide resin compositions obtained in Comparative Examples 1 to 4 were measured as follows.
Further, with respect to these resin compositions, an operation test of an electronic component, a falling weight impact test, a measurement of a linear expansion coefficient, and a warp test were performed as follows.

(1) Measurement of melt flow rate (MFR) According to JIS K-7210, temperature 230 ° C, load 2
The melt flow rate was measured under the condition of 1.18N.

(2) Operation test of electronic parts: An electronic board for testing is set in a mold and insert-molded, and after embedding the electronic parts, an operation test is carried out. .

(3) Drop Weight Impact Test Using the sample used in the above test (2), JIS K-7
Test according to No. 211 and apply a weight of 0.5 kg to 50c
A sample which was dropped from a height of m and was not broken or deformed by 50% or more was evaluated as ◯.

(4) Measurement of coefficient of linear expansion After molding a sample piece having a size of 127 × 12.7 × 3.2 mm, the long side of the sample piece was cut into 8 mm, and a thermomechanical analyzer (TMA) was used. The injection direction (MD: Machine di
rection) and -20 to 80 ° C in the vertical direction (TD)
The linear expansion coefficient in the range was measured.

(5) Warp test 0.8 m thickness cut into 100 × 30 mm sample size
The resin composition was insert-molded on one surface of the glass-epoxy-based printed wiring board of m to a thickness of 3.2 mm. After 24 hours at room temperature, the obtained molded product was placed on a horizontal plate and the maximum height and the minimum height were measured with a gauge.
Those with a difference of 0.5 mm or less were marked with a circle.

The above evaluation results are shown in Tables 1 to 3.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

As is clear from the results shown in Tables 1 to 3, by using the polyamide resin compositions of Examples 1 to 14 according to the present invention, the stability of the operation of the electronic component is ensured and the good resistance is obtained. It can be seen that impact resistance is obtained. In addition, the linear expansion coefficient in the vertical direction (TD) is
The size is smaller than that of, and the molded product is less likely to warp.

In Comparative Example 1 in which only the fibrous filler was blended and the scale-like filler was not blended, the vertical direction (TD)
The coefficient of linear expansion at is large and warpage occurs. It can be seen that in Comparative Example 2 in which the fibrous filler was not blended but only the scale-like filler was blended, good impact resistance was not obtained.

In Comparative Example 3, since the melt flow rate is low, it must be molded at a high temperature, and it is found that the operation of the electronic component is damaged. In Comparative Example 4, the melting peak temperature (T _pm ) of the polyamide resin
It can be seen that the impact resistance is not good because of low.

[0058]

According to the polyamide resin composition of the present invention, it can be molded at a relatively low temperature, has good impact resistance, and can prevent warping of a molded product. Therefore, the polyamide resin composition of the present invention is a polyamide resin composition suitable for insert molding for sealing and packaging electronic parts and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Nakano             19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan             Into Inc. F-term (reference) 4J002 CL011 CL031 CL071 CL081                       DE147 DE187 DE237 DJ007                       DJ036 DJ046 DJ056 DK007                       DL006 DL007 DM007 FA016                       FA037 FB076 FB086 FB146                       FB166 FD016 GQ00

Claims (5)

[Claims] 1. A polyamide resin having a melting peak temperature (T _pm ) of 140 ° C. or higher and lower than 210 ° C., 50 to 80 parts by weight, scale-like fillers 1 to 47.5 parts by weight, and fibrous fillers 1 to 47. 0.5 parts by weight and a total of 100 parts by weight, and a melt flow rate (MFR) of 100 g / 10.
The polyamide resin composition for insert molding, which has a temperature of at least 230 minutes (230 ° C.). 2. The number average molecular weight of the polyamide resin is 150.
The polyamide resin composition for insert molding according to claim 1, wherein the polyamide resin composition is less than 00. 3. The flaky filler is glass flake,
Alternatively, the polyamide resin composition for insert molding according to claim 1 or 2, which is a granule having glass flakes bonded thereto. 4. The polyamide resin composition for insert molding according to claim 1, wherein the flaky filler is a plate silicate. 5. The polyamide resin composition for insert molding according to claim 4, wherein the plate silicate is mica.