JPH0628921A - Oil for preventing electric contact failure - Google Patents

Abstract

PURPOSE:To provide excellent electric contact failure preventing performance, prolong each lifetime of parts and enhance reliability of the parts even in the case of coexistence with parts of a relay and the like by using amino denatured silicone oil including an amino group within a limited range. CONSTITUTION:Such silicone oil is used as to be expressed by a general unit formula and have an amine equivalent of 10,000-200,000 g/mol and viscosity of 10-100,000 cSt at 25 deg.C. The general unit formula is R<1>aR<2>bSiO4-a-b/2. wherein R<1> represents -R<3>-NH2 or -R<3>-NH2 or -R<3>-NHR<4>-NH2 (wherein R<3> and R<4> represent an alkylene group with carbon atoms of 1-8, respectively); R<2>, a uniequivalent hydrocarbon group with carbon atoms of 1-6; 0.0001<=a<=0.01; and 1.95<=a+b<=2.20. The amino denatured silicone oil including an amino group within a limited range exhibits an excellent effect of prevention of an electric contact failure due to low molecular siloxane. Consequently, it is possible to restrain an electric contact failure in a relay, a switch or the like to a low level, prolong a lifetime of parts, and enhance reliability of the parts.

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, which oil is used as a moisture-proof oil, an insulating oil, a cooling oil, a lubricating oil, a releasing oil, etc. for electronic and electric devices.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Silicone oil typified by dimethyl polysiloxane has excellent heat resistance, cold resistance, weather resistance and stable electrical characteristics, so it can be used for various home appliances, office equipment, computers, etc. to prevent moisture, insulation, and cooling. It is used as a lubricating oil, etc., and has high reliability for these electronic and electric devices.
It is an indispensable material for providing high functionality.

However, recently, as these electronic and electric devices have become highly functional and compact, there is a strong tendency for the contact pressure of switches and relays and the energy of switching loads to drop, and as a result, these devices are subject to operation stoppages and malfunctions. May occur. As a cause of this, there are various electrical contact defects in parts such as relays, switches, motors, corotrons, etc. It has been found that there are cases where the electrical contact defects are caused by the low-molecular-weight siloxane contained in the silicone oil.

The following methods have been proposed as a method for solving the problems caused by the low-molecular-weight siloxane. (1) Method of removing low-molecular siloxane in silicone oil under high temperature and reduced pressure, (2) Method of limiting load conditions of voltage and current (JP-A-61-20926)
No. 6), (3) a method of incorporating a special organic fluorine compound having a vapor pressure into silicone oil (JP-A-1-
104656 and 1-109615).

However, although the method (1) has been partially put into practical use, the cost is high, and the method (2) causes a decrease in the capacity of electronic / electrical equipment, and further (3). The method (2) has a problem that the silicone oil is volatilized under the use condition of the open type, so that the effect is reduced, and the fluorine compound to be added is expensive.

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

[0007]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has shown that the following general unit formula (1) has 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 electrical contact failure due to low-molecular siloxane. The present invention has been made by discovering that the effects can be exhibited, the electric contact failure of relays, switches, motors, corotrons, etc. can be suppressed to a low level, and that it has heat resistance equal to or higher than that of conventional dimethyl silicone oil. It came to.

[0008]

[Chemical 2] (However, R ¹ is —R ³ —NH ₂ or —R ³ —NHR ⁴ —NH ₂
And 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, although the reason why the amino-modified silicone oil is excellent in preventing electrical contact failure is not clear, ammonia or amino group-containing cyclic oligomer generated by thermal decomposition of amino group is adsorbed and coated on the metal surface of electrical contact. Therefore, it is presumed that the low-molecular-weight siloxane is converted to silica by the electric energy and prevents the silicone oil from being decomposed and adhered.

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

[0011]

[Chemical 3]

Where R¹Is -R³-NH₂Or -R³-N
HR^Four-NH₂Indicated by R³ , R^FourAre carbon atoms
An alkylene group of the number 1 to 8, preferably 2 or 3,
R³And 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 the form of being bonded to a silicon atom. Specific examples of such a monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, butyl group and hexyl group, cycloalkyl groups such as cyclopentyl group and cyclohexyl group, phenyl group and trifluoropropyl. Examples thereof include halogenated alkyl groups such as a group and a nonafluorohexyl group, but in the present invention, a methyl group is particularly preferable.

Further, a and b are 0.0001≤a≤0.
01 is a positive number satisfying 1.95 ≦ a + b ≦ 2.20. When a is less than 0.0001, the electrical contact failure prevention property is poor, and when a is more than 0.01, both the electrical contact failure prevention property and the heat resistance are deteriorated.

In the above silicone oil, it is important that the amino group content in amine equivalent is in the range of 10,000 to 200,000 g / mol, particularly in the range of 50,000 to 150,000 g / mol. preferable. If the amine equivalent is less than 10,000 g / mol or more than 200,000 g / mol, the electrical contact failure prevention property is deteriorated.

The above silicone oil is used at 25 ° C.
Viscosity at 100 to 100,000 centistokes (cs)
And more preferably in the range of 100 to 60,000 cs. If the viscosity is less than 10 cs, a large amount of volatile matter is contained, and when used at high temperature, these cannot be exerted for a long time because they are volatilized, causing electrical contact failure. I will end up. Further, when the viscosity exceeds 100,000 cs, the extensibility of the silicone oil becomes poor, so that the initial mold releasability decreases when used as a mold release agent, for example.

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

[0018]

[Chemical 4] (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, trimethylsiloxy-terminated polydimethylsiloxane, octamethylcyclotetrasiloxane, methylaminopropylpolysiloxane are used as raw materials, and a high temperature is obtained by using a basic catalyst. Polymerized in
It can be easily produced by removing low-molecular-weight siloxane to a certain level by _2- substitution high temperature vacuum stripping.

In this case, the amount of the low-molecular-weight siloxane represented by the mathematical formula (A) described below is 10,000 ppm or less, especially 3
It is preferably 000 ppm or less.

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

The oil for preventing electrical contact failure of the present invention comprising the above silicone oil is used for motors, relays, switches,
In various electronic / electrical devices, etc. incorporating corotron, etc., it has an extremely excellent effect in preventing electrical contact failure due to low-molecular siloxane. Therefore, it can be used as a moisture-proof oil, insulating oil, cooling oil for electronic / electrical devices, It is preferably used as a lubricating oil or the like.

[0023]

EXAMPLES The present invention will be specifically described below by showing 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 made of the following amino group-containing organopolysiloxanes (Examples 1 to 5 and Comparative Examples 1 and 2) and dimethylpolysiloxane (Comparative Example 3). The failure prevention oil was evaluated for prevention of failure of electrical contacts.

Example 1 Represented by the following average composition formula (3), 36,000 g of γ-aminopropyl group in terms of amine equivalent.
Organopolysiloxane having a low-molecular siloxane content of 7500 ppm and a viscosity at 25 ° C. of 310 cs.

[0026]

[Chemical 5]

[0027]

[Equation 1]

Example 2 Represented by the following average composition formula (4), γ-aminopropyl group was 97,000 g in terms of amine equivalent.
/ Mol content, the low molecular siloxane content of the above formula (A) is 5700 ppm, and the viscosity at 25 ° C. is 311
cs organopolysiloxane.

[0029]

[Chemical 6]

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

[0031]

[Chemical 7]

Example 4 A low molecular siloxane represented by the above formula (A), represented by the following average composition formula (6), containing an N-β (aminoethyl) γ-aminopropyl group in an amine equivalent of 35000 g / mol. The content is 6700ppm, 25
An organopolysiloxane having a viscosity at 300 ° C. of 300 cs.

[0033]

[Chemical 8]

Example 5 Represented by the following average composition formula (7), containing an N-β (aminoethyl) γ-aminopropyl group in an amine equivalent of 100,000 g / mol and having a low molecular siloxane content of 6200 ppm. , An organopolysiloxane having a viscosity at 25 ° C. of 315 cs.

[0035]

[Chemical 9]

[Comparative Example 1] Represented by the following average composition formula (8), the γ-aminopropyl group was 6300 g / amine in terms of amine equivalent.
Molar content, low molecular siloxane content of formula (A) is 84
000 ppm, viscosity at 25 ° C is 320 cs
Organopolysiloxane.

[0037]

[Chemical 10]

[Comparative Example 2] The average compositional formula (9) shown below was used, and the γ-aminopropyl group was 370000 in amine equivalent.
g / mol, low molecular siloxane content of formula (A) is 7000 ppm, viscosity at 25 ° C. is 305 c
s organopolysiloxane.

[0039]

[Chemical 11]

[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]

[Chemical 12]

In the organopolysiloxanes of the above Examples and Comparative Examples, the organopolysiloxane containing a large amount of the low molecular siloxane shown in Table 1 was stripped by heating under the conditions shown in Table 1 to remove the low molecular siloxane. The reduced one was used.

[0043]

[Table 1]

100 g of the above 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 life test in a hot air circulation dryer at 80 ° C. In the measurement, the motor current waveform was traced by an oscilloscope, and the electrical contact failure prevention property was evaluated based on the following evaluation criteria assuming that the electrical contact failure occurred when the waveform was confirmed to be disturbed. The results are shown in Table 2.

Evaluation Criteria ◯: Waveform is not disturbed ×: Waveform is disturbed

[0046]

[Table 2]

[0047]

INDUSTRIAL APPLICABILITY The oil for preventing electrical contact failure of the present invention has an excellent ability to prevent electrical contact failure and can suppress the electrical contact failure of relays, switches, motors, corotrons, etc. to a low level. Long life and high reliability are achieved.

Claims (1)

[Claims] 1. An electrical contact fault comprising a silicone oil represented by the following general unit formula (1), having an amine equivalent of 10,000 to 200,000 g / mol and a viscosity at 25 ° C. of 100 to 100,000 centistokes. Prevention oil. [Chemical 1] (However, R ¹ is —R ³ —NH ₂ or —R ³ —NHR ⁴ —NH ₂
And 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. )