JPS59165651A - Polyamide shape - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyamide moldings, and more particularly to polyamide moldings to which soldered metal strips are attached.

Polycaproamide (nylon 6) is used in a variety of applications, but when it is used in electrical components, it is often used in the form of t-co molded parts with attached metal pieces that require soldering. .

When soldering to one end of the metal piece, the nylon 6 is heated to a high temperature and the heat of the single piece of solder melts, causing many problems such as the metal piece attached to the molded product falling out from the molded product. In fact, nylon 6 is unsuitable for electrical components that have metal pieces that require soldering. Therefore, to overcome the disadvantages of nylon 6, polyhexamethylene adipamide (nylon 66), which has a relatively high melting point, is sometimes preferred as a material for polyamide molded products that have metal pieces that require soldering. many.

On the other hand, electrical parts require flame retardancy, so nylon 6
It is conceivable to mix melamine cyanurate as a flame retardant into 6 and make the above-mentioned molded product using the composition. Gas is trapped and bubbles are mixed in,
The molded product has blisters on its surface. Like this single f!
Although molded products made from blended compositions of homogeneous nylon 66 and melamine cyanurate have good solder resistance,
At present, it is difficult to obtain good molded products, and in fact they cannot be used as molding materials.

This will be explained using drawings as follows.

FIG. 1 is a perspective view of a molded product (3) in which a metal piece such as a pin (2) to be soldered is attached to a main body (1) made of a polyamide resin composition.

In the figure C, a molded product having a plurality of pins embedded therein, typically a so-called connector, is shown. When making this connector, first mold the main body (1) shown in Figure 2,
Next, the pin (2) is placed in the through hole (5) of the main body (1).

One end of the pin (2) (
It is obtained by applying one end (4A) of the conductor (4) to the conductor (4A) and soldering both ends.

First, the main body (
When melt injection molding (1) is carried out, there is a problem in that the flame retardant, melamine cyanurate, decomposes and foams to form the main body (1) containing air bubbles. Therefore, we used nylon 6, which has a low melting point, and molded the main body (1) under conditions that did not cause foaming, and then formed the pin (2).
When the end of the conductor is soldered to the end of the solder, the heat from melting the solder is transmitted to the pin (2), and the heat dissipated by the soldering iron causes the pin (2) to be attached to the main body (IA). ) also softens.

As a result, the pin (2) is tilted by 1, and in some cases T1.
There is a problem that the t-pin (2) may fall off and become stiff.

In order to solve the above problem, the inventors of the present invention conducted extensive research into abstraction and found that the main body (1) could be formed from a composition of polyamide with a specific melting point and melamine cyanurate. child.

That is, the above problem occurs when a metal piece is attached to a composition made of polyamide and melamine cyanurate and the polyamide is heated at 255°C.
This problem can be solved by creating a molded product characterized by being made of polyamide with a melting point of ~264°C.
What is Iu melting point here? - Company (PERKI
This refers to the polyamide melting peak temperature at 75:00 when the temperature of a sample is raised at 20°C/min using a DSC-IB type differential calorimeter (N-E HFF1R).

The method for manufacturing the molded article of the present invention and its characteristics will be specifically described below.

A polyamide to be used in the present invention is prepared.

The polyamide C may be any polyamide as long as it has the above-mentioned melting point, but preferably contains an equimolar salt of hexamethylenediamine-adipic acid (hereinafter referred to as AH salt) as a main component, ε-caprolactam (hereinafter referred to as CL), or equimolar ml of hexamethylene diamine and sepacic acid
A small amount of nylon 66/
6 or nylon 66/6/10.

Regarding the copolymerization composition of polyamide, in the case of nylon 66/6 copolymer as the starting material to be charged into the polymerization tank during polymerization, the ratio of AH salt to CL is 98.5/1. '5w
t% to 94. The range is O/6, Owt%, preferably 98/2 wt% to 95/5 wt%. In this case, ε-4-mino caproic acid can be used instead of CL, and AH salt, CL
Alternatively, a nylon 66/6 copolymer can be obtained by directly charging nylon 66 and nylon 6 into a polymerization vessel and depolymerizing them.

In the case of nylon 66/6/10 copolymer, the ratio of AH salt and SH salt ranges from 95/5 wt% to 85/l.
5 wt%, preferably 93/7 wt% to 9
A range of 0/10 wt% is preferred. In this case also A
Nylon 66, nylon 6.1 instead of H salt and SH salt
0 directly into the polymerization value and depolymerized to produce nylon 66/
6/10 copolymer can be obtained.

Melamine cyanurate used in the present invention is usually obtained by reacting melamine and cyanuric acid (or isocyanuric acid) in equimolar ratio water, but is not necessarily limited thereto. melamine cyanuré
Although 1. is preferably pure, it may contain a small amount of unreacted melamine or cyanuric acid (or isocyanuric acid).

The melamine cyanurate used in the present invention has an average particle size of 1
A fine powder of 00 μm or less is preferable because it is uniformly dispersed during kneading with polyamide. When the particle size of melamine cyanurate exceeds 10,077, uniform dispersion is difficult and furthermore, the mechanical properties of the molded article are impaired.

The method for dispersing melamine cyanurate in molded products is as follows:
Examples include a method of melt-kneading the above-mentioned polyamide and melamine/cyanurate using an extruder or the like, a method of melt-kneading the polyamide defined in the present invention and melamine, and then additionally kneading cyanuric acid (isocyanuric acid).

The amount of melamine cyanurate in the polyamide and melamine cyanurate composition thus obtained is from 3 to 30% by weight, preferably from 4 to 15% by weight, based on the total weight of the composition. Melamine cyanurate content in the composition is 3
If it is less than 30% by weight, the flame retardance will not be sufficient, and if it exceeds 30% by weight, the fluidity of the polyamide composition will be poor during the molding process, and the good mechanical properties of the polyamide will not be maintained.

In the composition of the present invention, known dyes and pigments such as carbon black and titanium dioxide, stearic acid or its aluminum, calcilum, barium, magnesium, lithium,
Metal soaps that are salts of zinc, etc., mono-, bis, amide, copper halides, etc. of stearic acid and aliphatic diamines such as methylene diamine and ethylene diamine, stabilizers such as hindered phenols, and antistatic agents such as polypropylene glycol. Other conventional additives may also be included.

The molded article of the present invention exhibits the following effects.

First, melamine/cyanurate does not decompose during the melt-molding process. Therefore, not only the original flame retardancy does not deteriorate, but also no air bubbles are introduced into the molded product, making it possible to obtain a stable molded product.

Next, when soldering a conductive wire to the pin of the molded product of the present invention, even if the heat is transmitted through the pin and the attachment is transmitted to the part, the pin will not be pulled out and the pin will fall off and become stiff. do not have.

The present invention is applicable to any molded product to which a metal piece that requires soldering is attached. In short, the radiant heat of the soldering iron transmits the heat to the soldering iron, and the radiant heat from the soldering iron makes it easy for the metal pieces to be attached to a defective size and shape. .

Next, the effects of the present invention will be explained using examples.

Example AH salt and CL were mixed in various proportions and charged into a reactor to prepare a nylon 66/6 copolymer having the copolymerization ratio shown in the table below. To 100 parts by weight of this copolymer, an average particle size of 10
Melamine/cyanurate containing 7 parts of 0μ was mixed for 3 minutes in a Henschel mixer, then melted and kneaded in a 65m extruder to prepare polyamide pellets containing melamine/cyanurate.

Next, the pellets were fed into an injection molding machine, and a rectangular test piece 5 inches long, 1/2 inch wide, and 1/16 inch thick was prepared. This test heather has a through hole (5) (cross-sectional diameter Q, 4 + u). Next, this through hole (5) has a diameter of 0.42.
[Length 106 tin plated 1 pin 5 wood,
Each pin was implanted so that its center portion was held in the main body (1).

After that (7'), heat it to 255℃ and solder one conductor to the end of the pin with a soldering iron. Requires 1 for soldering operation
This time is 3.3 seconds for each pin. The pulling force of this soldered pin was measured using an autograph and the results are shown in the table.

AH salt/C melting point °C Pin withdrawal o, (DSC turbidity strength f) Name Actual flow side 1
98.5/1.5 264 6102
97/3 262 6103 96/4
260 6004 9515
257 5855 94/6 255
520 Comparative Example 1 10010 266
- Foaming occurs during molding and good molded pieces cannot be obtained.2 90/10 250 2003
0/100 225 - Resin completely melted Comparative Examples 1 to 3 Same as Examples 1 to 5, only AH salt during AH/CL copolymerization (Comparative Example 1) AH salt/CL = 90/lQwt%, CL 100 parts by weight of the pellets and 7 parts by weight of melamine cyanurate were melted and mixed, and then Examples 1 to 5 were prepared.
A test piece was molded in the same manner as above, and the pullout force of the pin after soldering was measured.The results are summarized in the table.

As a result, if the melting point of the polyamide is 265°C or higher, it will foam during molding, making it impossible to obtain a good molded product.
It is well understood that when the melting point of the polyamide is below 255° C., the pull-out force of the pin after soldering is small and the pin sometimes becomes stiff during soldering.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a molded article according to the present invention (conventional), and FIG. 2 is a perspective view of only the main body thereof. (1)...Main body (2)...Pin (3)...Molded product (4)...Conductor (5)...Through hole patent applicant Higashishi Co., Ltd.

Claims (1)

[Claims] A metal piece to be soldered is attached to a polyamide composition consisting of polyamide and melamine cyanurate.
In this molded article, the polyamide has 255 to 264
A polyamide molded product characterized by being a polyamide with a melting point of ℃.