JP2776172B2 - Oil for preventing electrical contact failure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil for preventing electrical contact failure used as a moisture-proof oil, an insulating oil, a cooling oil, a lubricating oil, a release oil, etc. for electronic and electric equipment.

[0002]

2. Description of the Related Art
Silicone oil represented by dimethylpolysiloxane has excellent heat resistance, cold resistance, weather resistance and stable electrical properties, so it is moisture-proof, insulated, and cooled for various home appliances, office equipment, and computers. , Used as lubricating oil, etc.
It is an indispensable material for providing high functionality.

However, recently, with the advancement of functions and miniaturization of these electronic and electric devices, the contact pressure of switches and relays and the switching load energy have a strong tendency to decrease. May occur. As a distant cause, various electrical contact failures in components such as relays, switches, motors, and corotrons have been found to be caused by low-molecular siloxane contained in silicone oil in some cases.

The following method has been proposed as a method for solving the problem caused by the low molecular siloxane. (1) A method for removing low molecular siloxane in silicone oil at high temperature and reduced pressure; (2) A method for limiting the load conditions of voltage and current to a limited range (Japanese Patent Laid-Open No. 61-20926)
No. 6), and (3) a method in which a silicone oil contains a special organic fluorine compound having a vapor pressure.
104656, 1-109615).

[0005] However, although the above method (1) has been partially put to practical use, the cost is high, and the method (2) leads to a decrease in the performance of electronic and electric equipment. The method of (1) has a problem that the effect is reduced due to the volatilization of the silicone oil under open use conditions, and the fluorine compound to be added is expensive.

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an oil for preventing electrical contact failure, which has excellent electrical contact failure prevention properties and does not adversely affect the life and reliability of these components even when coexisting with components such as relays, switches, motors, and corotrons And

[0007]

The present inventors have made intensive studies to achieve the above object, and as a result, have the following general unit formula (1) and an amine equivalent of 10,000 to 200,000 g / mol. And a silicone oil having a viscosity of 100,000 to 100,000 centistokes at 25 ° C., that is, an amino-modified silicone oil containing an amino group in a limited range is excellent in preventing electric contact failure caused by low molecular siloxane. The present invention has been found to exhibit the effect, to be able to suppress the electrical contact failure of relays, switches, motors, corotrons, etc., and to have heat resistance equal to or higher than that of conventional dimethyl silicone oil. It has been reached.

[0008]

Embedded image (However, R ¹ is -R ³ -NH ₂ or -R ³ -NHR ⁴ -NH ₂
Wherein R ³ and R ⁴ are each an alkylene group having 1 to 8 carbon atoms. R ² represents a monovalent hydrocarbon group having 1 to 6 carbon atoms. a and b are 0.0001 ≦ a ≦ 0.01, 1.95 ≦
a + b ≦ 2.20. )

Here, it is not clear why the amino-modified silicone oil is excellent in preventing electrical contact failure, but ammonia or an amino group-containing cyclic oligomer generated by thermal decomposition of an amino group is adsorbed and coated on the surface of the electrical contact metal. Therefore, it is presumed that the low-molecular-weight siloxane is changed to silica by the electric energy, thereby preventing the decomposition and adhesion of the silicone oil.

Hereinafter, the present invention will be described in more detail. The silicone oil constituting the oil for preventing electrical contact failure of the present invention is represented by the following formula (1).

[0011]

Embedded image

Where R¹Is -R^Three-NH_TwoOr -R^Three-N
HR^Four-NH_TwoAnd R^Three , R^FourIs a carbon atom
An alkylene group of the formulas 1 to 8, preferably 2 or 3,
R^ThreeAnd R^FourMay be the same or different.

R ² is a monovalent hydrocarbon group having 1 to 6 carbon atoms and is contained in the molecule in a form bonded to a silicon atom. Specific examples of such a monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group, a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a phenyl group, and trifluoropropyl. And a halogenated alkyl group such as a nonafluorohexyl group. In the present invention, a methyl group is particularly preferable.

Further, a and b are 0.0001 ≦ a ≦ 0.
01, 1.95 ≦ a + b ≦ 2.20. If a is less than 0.0001, the electrical contact failure prevention properties are poor, and if a exceeds 0.01, both the electrical contact failure prevention properties and the heat resistance decrease.

It is important that the above-mentioned silicone oil has an amino group content in the range of 10,000 to 200,000 g / mol in terms of amine equivalent, particularly in the range of 50,000 to 150,000 g / mol. preferable. When the amine equivalent is less than 10,000 g / mol or more than 200,000 g / mol, the ability to prevent electrical contact failure is reduced.

The above-mentioned silicone oil has a temperature of 25 ° C.
100,000 to 100,000 centistokes (cs)
And more preferably in the range of 100 to 60,000 cs. When the viscosity is less than 10 cs, a large amount of volatile components is contained in particular, and when used at a high temperature, these components volatilize and cannot exert their effects over a long period of time. I will. On the other hand, if the viscosity exceeds 100,000 cs, the extensibility of the silicone oil becomes poor, so that, for example, when used as a release agent, the initial release properties are reduced.

The organopolysiloxane (silicone oil) represented by the general formula (1) may have any of a linear, branched and cyclic structure, but a linear one is generally preferred. There is a particularly preferable one represented by the following average composition formula (2).

[0018]

Embedded image (However, m is a positive number of 8 to 1500 and n is 0.002 to 30.)

This silicone oil can be produced by a method known per se, for example, using trimethylsiloxy-terminated polydimethylsiloxane, octamethylcyclotetrasiloxane, and methylaminopropylpolysiloxane as raw materials and heating at a high temperature using a basic catalyst. Polymerized in N
It can be easily manufactured by removing low-molecular siloxane to a certain level by _2- substitution high-temperature vacuum stripping.

In this case, the amount of the low-molecular siloxane represented by the formula (A) described below is 10,000 ppm or less, particularly 3 ppm.
It is preferable that the concentration is not more than 000 ppm.

For the removal of the low-molecular-weight siloxane, the method of stripping by heating the silicone oil under reduced pressure as described above can be suitably adopted. This stripping is performed under reduced pressure of 5 mmHg or less at 280 to 32 mm.
The heating is preferably performed by heating at 0 ° C., more preferably 280 to 310 ° C., for 6 to 10 hours, more preferably 7 to 10 hours, and at this time, bubbling with nitrogen gas is preferred. Thereby, the low molecular siloxane amount can be reliably achieved.

The oil for preventing electrical contact failure according to the present invention comprising the above-mentioned silicone oil includes motors, relays, switches,
In various electronic and electric devices incorporating Corotron, etc., it has an extremely excellent effect on preventing failure of electric contacts caused by low molecular siloxane, and therefore, moisture-proof oil, insulating oil, cooling oil, It is suitably used as a lubricating oil or the like.

[0023]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Examples 1 to 5 and Comparative Examples 1 to 3 Electrical contacts comprising the following amino group-containing organopolysiloxanes (Examples 1 to 5 and Comparative Examples 1 and 2) and dimethylpolysiloxane (Comparative Example 3) The electrical contact failure prevention performance of the failure prevention oil was evaluated.

Example 1 A γ-aminopropyl group represented by the following average composition formula (3) was converted to an amine equivalent of 36000 g.
/ Mol, an organopolysiloxane having a low molecular siloxane content represented by the following formula (A) of 7500 ppm and a viscosity at 25 ° C. of 310 cs.

[0026]

Embedded image

[0027]

(Equation 1)

Example 2 A γ-aminopropyl group represented by the following average composition formula (4) was 97000 g in terms of amine equivalent.
/ Mol, the low-molecular-weight siloxane content of the above formula (A) is 5700 ppm, and the viscosity at 25 ° C is 311 ppm.
cs organopolysiloxane.

[0029]

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Example 3 A γ-aminopropyl group represented by the following average composition formula (5) was converted to an amine equivalent of 200,000.
g / mol, the low-molecular-weight siloxane content of the above formula (A) is 6300 ppm, and the viscosity at 25 ° C is 30.
7 cs organopolysiloxane.

[0031]

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Example 4 A low-molecular-weight siloxane represented by the above formula (A) containing an N-β (aminoethyl) γ-aminopropyl group represented by the following average composition formula (6) and having an amine equivalent of 35,000 g / mol. Content is 6700 ppm, 25
An organopolysiloxane having a viscosity at 300C of 300 cs.

[0033]

Embedded image

Example 5 The composition was represented by the following average composition formula (7) and contained 100,000 g / mol of N-β (aminoethyl) γ-aminopropyl group in terms of amine equivalent, and had a low molecular siloxane content of 6,200 ppm. , An organopolysiloxane having a viscosity of 315 cs at 25 ° C.

[0035]

Embedded image

Comparative Example 1 A compound represented by the following average composition formula (8) and having a γ-aminopropyl group in an amine equivalent of 6300 g /
Moles, and the low-molecular-weight siloxane content of the formula (A) is 84
000 ppm, and the viscosity at 25 ° C. is 320 cs.
Organopolysiloxane.

[0037]

Embedded image

[Comparative Example 2] A compound represented by the following average composition formula (9) and having a γ-aminopropyl group in an amine equivalent of 370000
g / mol, the low-molecular-weight siloxane content of the formula (A) is 7000 ppm, and the viscosity at 25 ° C. is 305 c
s organopolysiloxane.

[0039]

Embedded image

[Comparative Example 3] The low-molecular siloxane content of the formula (A) represented by the following average composition formula (10) is 6500 p
dimethylpolysiloxane having a viscosity of 290 cs at 25 ° C.

[0041]

Embedded image

The organopolysiloxanes of the above Examples and Comparative Examples were removed by heating and stripping the organopolysiloxane containing a large amount of the low molecular siloxane shown in Table 1 under the conditions shown in Table 1. The reduced one was used.

[0043]

[Table 1]

100 g of the above-mentioned organopolysiloxane (oil for preventing electrical contact failure) was placed in a container having a volume of 5 liters, sealed, and then subjected to a micromotor accelerated durability test in a hot air circulation type dryer at 80 ° C. In the measurement, the motor current waveform was tracked by an oscilloscope, and when the waveform disturbance was confirmed, electrical contact failure prevention was evaluated based on the following evaluation criteria on the assumption that an electrical contact failure occurred. Table 2 shows the results.

Evaluation criteria ○: no disturbance in the waveform ×: disturbance in the waveform

[0046]

[Table 2]

[0047]

The oil for preventing electrical contact failure according to the present invention has excellent electrical contact failure prevention properties and can suppress electrical contact failures of relays, switches, motors, corotrons, etc. Life extension and high reliability are achieved.

Claims (1)

(57) [Claims] 1. An electric contact failure comprising a silicone oil represented by the following general formula (1), having an amine equivalent of 10,000 to 200,000 g / mol, and having a viscosity at 25 ° C. of 100 to 100,000 centistokes. Prevention oil. Embedded image (However, R ¹ is -R ³ -NH ₂ or -R ³ -NHR ⁴ -NH ₂
Wherein R ³ and R ⁴ are each an alkylene group having 1 to 8 carbon atoms. R ² represents a monovalent hydrocarbon group having 1 to 6 carbon atoms. a and b are 0.0001 ≦ a ≦ 0.01, 1.95 ≦
a + b ≦ 2.20. )