JP2017073299A - Surface protective agent for electrical contact and electrical contact using the same, and connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface protective agent for electrical contact composed by having a material containing tin, compared to conventional, in which contat stability can be enhanced, and to provide an electrical contact using the same, and a connector.SOLUTION: A surface protective agent for electrical contact composed by having a material containing tin, contains an organic tin compound. Consequently, fretting wear can be suppressed. As a result, better contact stability can be obtained, compared with conventional, and such problems as contact failure, malfunction, and durability deterioration can be suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a surface protective agent for an electrical contact configured with a material containing tin, an electrical contact using the same, and a connector.

  A wide variety of electronic devices are mounted on automobiles, industrial machines, optical devices, and precision devices. For example, a wire harness is routed in the electronic device described above in order to transmit power, a control signal, and the like. The wire harness includes a plurality of electric wires and a connector.

  The connector includes a connector terminal and a connector housing. The connector terminal is made of a conductive sheet metal or the like and is electrically connected to the mating connector.

  Conventionally, a connector terminal in which a surface of a base material such as copper or a copper alloy is plated with tin plating has been used (Patent Document 1).

JP 2008-248294 A

  However, since tin plating or tin alloy plating forms a hard oxide film on the surface, there is a problem that fretting wear occurs due to peeling and contact stability is lowered. Then, due to the decrease in contact stability, problems such as contact failure, malfunction, and deterioration of durability have occurred.

  Also, it is difficult to completely eliminate the occurrence of fretting wear even if an oil agent is interposed between the tin plating and the mating connector. Conventionally, it is effective for tin plating formed on the surface of the connector terminal. No protective agent was present.

  The invention described in Patent Document 1 discloses a configuration in which lubricating particles are contained in a surface plating layer of tin plating.

  However, in the configuration in which the lubricating particles are scattered in the plating layer, there is a problem that the lubricating particles are missing from the surface plating layer due to sliding with the mating connector. As an example of the lubricating particles, it is described that a capsule containing a lubricant is applied (see [0026] of Patent Document 1). In addition, it is described that the capsule is crushed by sliding with the mating connector to release the lubricant, and the lubricant is supplied to the mating connector. However, since it is assumed that the surface plating layer is scraped until the capsule is exposed, the contact stability cannot be sufficiently improved. Further, since the supply of the lubricant is based on the premise that the capsule is crushed, it is unstable and variation in contact stability is likely to occur. In addition, in the configuration in which the lubricating particles are interspersed in the plating layer, it is considered that an increase in electric resistance and variation in electric resistance are likely to occur and affect the conductivity.

  Therefore, the present invention has been made in view of such problems, and in the surface protective agent for electrical contacts configured with a material containing tin, the contact stability is improved as compared with the conventional case. An object of the present invention is to provide a surface protective agent for electrical contacts, an electrical contact using the same, and a connector.

  The present invention is a surface protective agent for an electrical contact configured with a material containing tin, and includes an organic tin compound.

  In the present invention, the tin atom of the organotin compound is preferably in the state of 1 organic substituted tin, 2 organic substituted tin, or 4 organic substituted tin.

  In the present invention, the organotin compound includes dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin dilaurate, dimethyltin bis (dodecyl mercaptide), dibutyltin bis (dodecyl mercaptide), dioctyltin bis (dodecyl mercaptide), dimethyltin. Bis (2-ethylhexyl thioglycolate), dibutyltin bis (2-ethylhexyl thioglycolate), dioctyltin bis (2-ethylhexyl thioglycolate), dimethyltin diacetate, dibutyltin diacetate, dioctyltin diacetate, Dimethyltin maleate, dibutyltin maleate, dioctyltin maleate, dimethyltin bisthioglycerol, dibutyltin bisthioglycerol, dioctyltin bisthioglyce Lumpur, octyl tin tris (2-ethylhexyl thioglycolate), bis (beta-methoxycarbonylethyl) of tin dilaurate, are preferably selected from at least one kind.

  In particular, in the present invention, the organotin compound preferably contains at least one of dioctyltin dilaurate, dioctyltin bis (2-ethylhexyl thioglycolate), and dioctyltin maleate.

  Moreover, the surface protective agent for electrical contacts in this invention can be set as the structure containing the said organotin compound and a solvent. At this time, the solvent is preferably an organic solvent capable of making the organotin compound into a uniform solution. Specifically, the solvent is an aromatic hydrocarbon solvent, an alcohol solvent, an ester solvent, an ether solvent, a ketone solvent, a glycol ether solvent, an alicyclic hydrocarbon solvent, an aliphatic hydrocarbon solvent. It is preferably selected from at least one of a solvent, an aliphatic or an aromatic hydrocarbon mixture.

  Moreover, in this invention, it is preferable that the said solvent contains the fluorine solvent as a nonflammable solvent at least. Specifically, the fluorine solvent is hydrofluoroether, hydrofluorocarbon, hydrochlorofluorocarbon, perfluorocarbon, perfluoropolyether, benzotrifluoride, bis (trifluoromethyl) benzene, difluoroacetone, hydrofluoroolefin, and It is preferable that at least any one of hydrochlorofluoroolefins is selected. Particularly in the present invention, the fluorine solvent preferably contains at least hydrochlorofluoroolefin.

  Moreover, the surface protective agent for electrical contacts in the present invention can be configured to contain the organotin compound and a lubricating component of lubricating oil or grease. At this time, the lubricating component may be selected from at least one of mineral oil, synthetic hydrocarbon oil, diester oil, polyol ester oil, ether oil, glycol oil, silicone oil, and fluorine oil. preferable.

  In the present invention, the thickener contained in the grease includes lithium soap, calcium soap, sodium soap, aluminum soap, lithium composite soap, calcium composite soap, aluminum composite soap, urea compound, organic bentonite, polytetrafluoroethylene. , Silica gel, and sodium terephthalate are preferably selected from at least one of them.

  Moreover, the electrical contact in the present invention has a contact configured by including a material containing tin, and a protective layer coated on the contact surface, and the protective layer is for the electrical contact described above. It is formed using a surface protective agent and contains at least the organotin compound.

  Further, the connector according to the present invention has a connector terminal configured with a material containing tin, and a protective layer coated on the surface of the terminal, and the protective layer is for the electrical contact described above. It is formed using a surface protective agent and contains at least the organotin compound.

  According to the present invention, fretting wear can be suppressed by using a surface protective agent for an electrical contact containing an organotin compound. As a result, it is possible to obtain better contact stability as compared with the conventional case, and it is possible to suppress problems such as contact failure, malfunction, and durability deterioration.

1A is a partial cross-sectional view showing a part of the connector, and FIG. 1B is a partial enlarged cross-sectional view showing an enlarged range A surrounded by a dotted line in FIG. 1A.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  As a result of sincere research on a protective agent for electrical contacts composed of a material containing tin, the present inventors can suppress fretting wear by using a protective agent containing an organic tin compound. It was possible to obtain better contact stability than in the prior art.

(Organic tin compounds)
The “organotin compound” includes a direct bond between a tin atom and a carbon atom constituting an organic group in the compound.

  The tin atom of the organotin compound in this embodiment is preferably in the state of 1 organosubstituted tin, 2 organosubstituted tin, or 4 organosubstituted tin. 3Organic substituted tin is highly toxic and cannot be used due to problems with the human body and the environment.

When an organotin compound is shown as a chemical formula, it can be represented by RSnX ₃ (monoorganotin), R ₂ SnX ₂ (diorganotin), R ₄ Sn (tetraorganotin). _Among, R represents indicated by C _{m H 2m,} in the range of m = 10 to 20. X is at least one selected from laurate, acetate, maleate, 2-ethylhexyl thioglycolate, thioglycerol, and the like.

  The organotin compound in the present embodiment includes dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin dilaurate, dimethyltin bis (dodecyl mercaptide), dibutyltin bis (dodecyl mercaptide), dioctyltin bis (dodecyl mercaptide), dimethyltin bis (2-ethylhexyl thioglycolate), dibutyltin bis (2-ethylhexyl thioglycolate), dioctyltin bis (2-ethylhexyl thioglycolate), dimethyltin diacetate, dibutyltin diacetate, dioctyltin diacetate, dimethyl Tin maleate, dibutyltin maleate, dioctyltin maleate, dimethyltin bisthioglycerol, dibutyltin bisthioglycerol, dioctyltin bisthioglyce Lumpur, octyl tin tris (2-ethylhexyl thioglycolate), bis (beta-methoxycarbonylethyl) of tin dilaurate, are preferably selected from at least one kind.

  Among these, at least any one of dioctyltin dilaurate (see the following chemical formula 1), dioctyltin bis (2-ethylhexyl thioglycolate) (see the following chemical formula 2), and dioctyltin maleate (see the following chemical formula 3). It is more preferable that 1 type is included.

  In the present embodiment, it is most preferable that at least dioctyltin dilaurate is included as the organotin compound. Dioctyltin dilaurate is considered to have very good affinity with tin plating on the contact surface (for example, connector terminal) surface, and as shown in the experiment described later, by using dioctyltin dilaurate as an organotin compound, It is possible to improve the contact stability of the connector terminal more effectively.

(Solvent type)
The surface protective agent for electrical contacts according to the present embodiment includes the organotin compound described above and a solvent.

  It is preferable that the solvent in this Embodiment is an organic solvent which can make an organotin compound into a uniform solution. Here, the “homogeneous solution” is a state in which no suspension of the solution or generation of a precipitate occurs, and it can be visually confirmed.

  Here, the organotin compound is preferably in the range of 0.01 to 20 parts by weight when the total amount of the protective agent is 100 parts by weight. When the content of the organotin compound is less than 0.01 parts by weight, the intended effect of achieving contact stability is insufficient even when the organotin compound is contained in the surface protective agent for electrical contacts. In addition, when the content of the organic tin compound exceeds 20 parts by weight, the amount of the organic tin compound in the surface protective agent for electrical contacts is too large, and it is difficult to obtain a uniformly mixed solvent. Even if the content of the tin compound is increased, further improvement of the intended effect according to the content cannot be obtained, and the price becomes expensive, which is not practical. In addition, the content of the organic tin compound and the amount of the solvent are 0.01 parts by weight to 20 parts by weight of the organic tin compound, depending on the intended use, such as the required protective layer thickness and usage environment. It can adjust suitably within the range of content.

  The organic solvent in the present embodiment is used as a diluting solvent for the organotin compound. In order to uniformly apply the organotin compound to the contact with a thin film, the organic solvent is preferably volatilized quickly after the application. When the boiling point of the organic solvent exceeds 200 ° C., the drying property is poor. Therefore, the boiling point is preferably 200 ° C. or less (1 atm), more preferably 150 ° C. or less, and further preferably 130 ° C. or less. In the present embodiment, one type of solvent may be used, or a plurality of types of solvents having different types may be used.

  Here, the solvent can be divided into a flammable solvent and a non-flammable solvent. Specific examples of combustible solvents include aromatic hydrocarbon solvents, alcohol solvents, ester solvents, ether solvents, ketone solvents, glycol ether solvents, alicyclic hydrocarbon solvents, aliphatic carbonization. It is preferably selected from at least one of a hydrogen solvent, an aliphatic or aromatic hydrocarbon mixture. For example, since halogenated hydrocarbons are highly toxic to animals and plants including humans, it is not preferable to use them as solvents in the present embodiment. In addition, dioxins that are generated when organic substances containing chlorine are burned are persistent organic pollutants that, when released into the environment, affect the ecosystem over a long period of time. Therefore, they are used as solvents in this embodiment. That is not preferred.

  The aromatic hydrocarbon solvent can be selected from, for example, toluene, xylene, styrene and the like.

  The alcohol solvent can be selected from, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, isopentyl alcohol, and the like.

  The ester solvent can be selected from, for example, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, and the like.

  The ether solvent can be selected from, for example, ethyl ether, 1,4-dioxane, tetrahydrofuran and the like.

  The ketone solvent can be selected from, for example, acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone and the like.

  The glycol ether solvent can be selected from, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, and the like.

  The alicyclic hydrocarbon solvent can be selected from, for example, cyclohexanone, methylcyclohexanone, cyclohexanol, methylcyclohexanol and the like.

  The aliphatic hydrocarbon solvent can be selected from, for example, normal hexane.

  The aliphatic or aromatic hydrocarbon mixture can be selected from, for example, petroleum ether, petroleum benzine and the like.

  Moreover, in this Embodiment, it is preferable that a fluorine solvent is included at least as a nonflammable solvent. Specific examples of the fluorine solvent include hydrofluoroether, hydrofluorocarbon, hydrochlorofluorocarbon, perfluorocarbon, perfluoropolyether, benzotrifluoride, bis (trifluoromethyl) benzene, difluoroacetone, hydrofluoroolefin, and hydro It is preferable that at least any one of chlorofluoroolefins is selected.

  Moreover, it is preferable to select at least hydrochlorofluoroolefin from among the fluorine solvents listed above from the viewpoints of compatibility with the organotin compound, global warming potential, and ozone depletion potential. As shown in the experiment described later, by using hydrochlorofluoroolefin as the nonflammable organic solvent, it is possible to more effectively improve the contact stability of the connector terminal as a contact.

  The preferred range of the content of the organotin compound in the solvent and the boiling point of the organic solvent does not change whether the organic solvent is a flammable organic solvent or a nonflammable organic solvent.

(Lubricant type, grease type)
The surface protective agent for electrical contacts according to the present embodiment includes the organotin compound described above and a lubricating component of lubricating oil or grease. That is, the lubricating oil type includes an organotin compound and a lubricating oil as a lubricating component. The grease type includes an organotin compound, a base oil as a lubricating component, and a thickener.

  Here, the organotin compound is preferably in the range of 0.01 to 20 parts by weight when the total amount of the protective agent is 100 parts by weight. When the content of the organotin compound is less than 0.01 parts by weight, the intended effect of achieving contact stability is insufficient even when the organotin compound is contained in the surface protective agent for electrical contacts. In addition, when the content of the organic tin compound exceeds 20 parts by weight, the amount of the organic tin compound in the surface protective agent for electrical contacts is too large, and the lubricating performance is deteriorated. Even if the amount is increased, the intended effect according to the content cannot be further improved, and the price becomes expensive, which is not practical. Further, the content of the organic tin compound and the amount of the lubricating component can be appropriately adjusted within the range of the content in which the organic tin compound is 0.01 parts by weight to 20 parts by weight, depending on the intended use. .

  The lubricating component is preferably selected from at least one of mineral oil, synthetic hydrocarbon oil, diester oil, polyol ester oil, ether oil, glycol oil, silicone oil, and fluorine oil. These lubricating components can be used alone or in combination of two or more, and the amount used is not particularly limited, and the amount can be selected according to the coating suitability. As the lubricating component, poly α olefins and ethylene α olefin oligomers are particularly preferable from the viewpoint that they can be used in a wide temperature range, compatibility with rubbers and resins, and compatibility with additives.

  The thickener contained in the grease of the present embodiment is lithium soap, calcium soap, sodium soap, aluminum soap, lithium composite soap, calcium composite soap, aluminum composite soap, urea compound, organic bentonite, polytetrafluoroethylene, It is preferable that at least one selected from silica gel and sodium terephthalate. The thickener is preferably lithium stearate and / or lithium 12-hydroxystearate from the viewpoint of shear stability. Lithium soap is a saponification reaction product of a fatty acid or a derivative thereof and lithium hydroxide. The fatty acid used is at least one selected from the group consisting of saturated or unsaturated fatty acids having 2 to 22 carbon atoms and derivatives thereof. Further, “soap” obtained by reacting the above fatty acid or derivative thereof with lithium hydroxide is commercially available, and this can also be used.

  Moreover, antioxidant, rust preventive agent, metal corrosion inhibitor, oiliness agent, antiwear agent, extreme pressure agent, solid lubricant, etc. can be added as needed. The content of these additives is within the range of about 0.01 to 20 parts by weight. The antioxidant can be selected from hindered phenol, alkylated diphenylamine, phenyl-α-naphthylamine and the like. The rust preventive agent can be selected from carboxylic acids such as stearic acid, dicarboxylic acids, metal soaps, carboxylic acid amine salts, metal salts of heavy sulfonic acids, or carboxylic acid partial esters of polyhydric alcohols. The metal corrosion inhibitor can be selected from benzotriazole or benzimidazole. The oily agent may be selected from amines such as laurylamine, higher alcohols such as myristyl alcohol, higher fatty acids such as palmitic acid, fatty acid esters such as methyl stearate, or amides such as oleylamide. it can. The antiwear agent can be selected from zinc, sulfur, phosphorus, amine, ester, and the like. The extreme pressure agent should be selected from zinc dialkyldithiophosphate, molybdenum dialkyldithiophosphate, sulfurized olefin, sulfurized oil, methyltrichlorostearate, chlorinated naphthalene, benzylated iodinated, fluoroalkylpolysiloxane, lead naphthenate, etc. Can do. The solid lubricant can be selected from graphite, graphite fluoride, polytetrafluoroethylene, melamine cyanurate, molybdenum disulfide, antimony sulfide, and the like.

(connector)
1A is a partial cross-sectional view showing a part of the connector, and FIG. 1B is a partial enlarged cross-sectional view showing an enlarged range A surrounded by a dotted line in FIG. 1A.

  As shown in FIG. 1A, the connector 1 includes a male connector 2 and a female connector 3. The male connector 2 includes a resin housing 4 and a metal male terminal (connector terminal) 5. The female connector 3 includes a resin housing 6 and a female terminal (connector terminal) 7. For example, a part of the female terminal 7 is composed of a leaf spring structure 7a. FIG. 1A shows a state in which the male connector 2 is inserted into the female connector 3, and the male terminal 5 of the male connector 2 and the female terminal 7 of the female connector 3 are in electrical contact.

  As shown in FIG. 1B, the male terminal 5 includes a base material 10, a surface plating layer 11 formed on the surface of the base material 10, and a protective layer 12 formed on the surface of the surface plating layer 11. Composed.

  The material of the base material 10 is not limited, but depending on the mechanical strength, heat resistance, conductivity, etc., for example, copper alloys such as phosphor bronze and beryllium copper, iron alloys such as pure iron and stainless steel, nickel alloys Etc.

  Moreover, the surface plating layer 11 is a plating layer containing tin, and may be formed of tin alone or a tin alloy. Moreover, the surface plating layer 11 should just have the tin plating layer exposed on the surface, for example, may be comprised by laminated structure with a silver plating layer etc.

  The protective layer 12 is a layer configured to include the organotin compound in the present embodiment. The film thickness of the protective layer 12 is about several μm to several hundred μm, and the film thickness can be adjusted according to the intended use. For example, when the organic tin compound is applied directly to the surface of the surface plating layer 11, the thickness of the protective layer 12 is about several tens of μm to several hundreds of μm. Moreover, in the case of a solvent type, when a protective agent is applied to the surface of the surface plating layer 11, the solvent volatilizes, so that the thickness of the protective layer 12 can be reduced and several μm to several μm depending on the content of the organic tin compound Various adjustments can be made in units of 10 μm. The volatilization state varies depending on the solvent to be used, and some may volatilize within a few minutes, or may be subjected to a drying process to promote solvent removal. Further, in the lubricating oil type and the grease type, since the lubricating component remains on the surface plating layer 11, although depending on the application amount, the film thickness as the protective layer 12 becomes thicker than the solvent type described above, and several tens of times. It is set to about μm to several hundred μm.

  As shown in the drawing, the protective layer 12 may be formed on the entire surface of the surface plating layer 11 or may be partially formed. “Partial” refers to a lattice shape, a sea stripe shape (for example, a dot shape), a stripe shape, or the like, and a portion without the protective layer 12 exists on the surface plating layer 11. Thus, even if the protective layer 12 is partially provided, the tin surface can be appropriately protected, and it is possible to improve electrical conductivity and insertion / extraction properties as compared with the conventional product. In addition, the film thickness of the protective layer 12 is measured by an average film thickness. For example, the film thickness of the protective layer 12 is measured at a plurality of points (at least 3 points) on the protective layer 12 using a stylus type surface shape measuring instrument or an ultrasonic method, and these are arithmetically averaged. It is shown as a value.

  The surface protective agent in the present embodiment (organotin compound alone, regardless of whether it is a solvent type, a lubricating oil type, or a grease type) is used for an electrical contact configured with a material containing tin, Thereby, the tin surface can be appropriately protected, that is, the peeling of the surface plating layer 11 can be prevented even by repeated insertion and removal of the terminals, so that fretting wear can be suppressed and the contact stability between the male terminals 5 and the female terminals 7 can be suppressed. Can be improved as compared with the prior art. Specifically, as shown in the experimental results to be described later, it is possible to improve the continuity and insertion / removability compared to the conventional product.

  1B shows the cross-sectional structure of the male terminal 5, the surface protective agent in the present embodiment may be applied to at least one of the male terminal 5 and the female terminal 7.

  In addition, the presence or absence of implementation of this invention can be discriminate | determined by analyzing the protective agent traded in a distribution process. The presence or absence of this embodiment can also be determined by analyzing the protective layer formed on the terminal surface of the connector. At this time, in the solvent type, the solvent is volatilized and does not exist in the protective layer, but it is possible to estimate the use of the solvent type from the film thickness of the protective layer.

  Moreover, although the connector was mentioned as an example of an electrical contact in the above, the surface protection agent of this Embodiment is not limited for connector terminals. Examples of the contacts include terminals such as switches and PC cards in addition to the connector terminals. In addition, the surface protective agent of this Embodiment is applied effectively to a connector terminal.

  Hereinafter, the present invention will be described in detail with reference to examples carried out in order to clarify the effects of the present invention. In addition, this invention is not limited at all by the following examples.

  Examples 1 to 8, Reference Example 1, Reference Example 2, and Conventional Examples were prepared with the formulations shown in Table 1 and Table 2 below. The raw materials used are as follows.

Example 1
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 100 parts by weight (Example 2)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 1.0 part by weight Combustible solvent Normal hexane (boiling point 69 ° C.): 99.0 parts by weight (Example 3)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 1.0 part by weight flammable solvent Exol D40 (boiling point 166 ° C.): 99.0 parts by weight (Example 4)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 1.0 part by weight Nonflammable solvent Hydrochlorofluoroolefin (manufactured by Central Glass, Model No .: 1233Z): 99.0 parts by weight (Example 5)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 0.01 part by weight Nonflammable solvent Hydrochlorofluoroolefin (manufactured by Central Glass, Model No .: 1233Z): 99.99 parts by weight (Example 6)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 1.0 part by weight Lubricating oil (base oil) Polyalphaolefin (kinematic viscosity (40 ° C.): 30 mm ² / s): 99.0 parts by weight ( Example 7)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 0.01 parts by weight Lubricating oil (base oil) Polyalphaolefin (kinematic viscosity (40 ° C.): 30 mm ² / s): 99.99 parts by weight ( Example 8)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 1.0 part by weight Base oil Polyalphaolefin (kinematic viscosity (40 ° C.): 30 mm ² / s): 89.0 parts by weight Thickener Lithium soap (Lithium 12-hydroxystearate): 10.0 parts by weight (Reference Example 1)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 0.005 parts by weight Non-flammable solvent Hydrochlorofluoroolefin (manufactured by Central Glass, Model No .: 1233Z): 99.995 parts by weight (Reference Example 2)
Organotin compound Dioctyltin dilaurate (C ₄₀ H ₈₀ O ₄ Sn): 0.005 parts by weight Base oil Polyalphaolefin (kinematic viscosity (40 ° C.): 30 mm ² / s): 89.995 parts by weight Thickener Lithium soap (Lithium 12-hydroxystearate): 10.0 parts by weight (conventional example)
Amine-based rust inhibitor 2.0 parts by weight Amine-based antioxidant: 2.0 parts by weight Organic acid oil improver: 2.0 parts by weight High-viscosity synthetic hydrocarbon oil: 94.0 parts by weight

  For Examples 2 to 7 and Reference Example 1, each raw material was weighed and mixed by stirring to obtain a uniform solution. In Example 8 and Reference Example 2, lithium soap was synthesized in the presence of base oil, and the temperature was increased while stirring. Next, after cooling to 80 ° C. or lower, dioctyltin dilaurate was formulated, and a uniform grease composition was obtained by using a three-stage roll mill, a disper mill, a colloid mill, or the like. The blending penetration is NLGI No. It adjusted with 2 grades. The test method is based on JIS K 2220.

  As an evaluation method, a connector was attached to a desktop vibration tester, vibration was applied for 96 hours at frequencies of 100 Hz, 2 G, and room temperature, and the electrical conductivity at that time was measured with an oscilloscope. A case where the electrical conductivity was good was evaluated as ◯, a case where the electrical conductivity was slightly unstable was evaluated as Δ, and a case where the electrical conductivity was unstable was evaluated as ×. Moreover, the insertion / extraction was performed 100 times as an insertion / extraction test, and the presence or absence of the sliding wear at that time was confirmed. The case where there was no wear was marked as ◯, the case where there was a little wear, and the case where there was wear as x. In the experiment, Yazaki Sogyo Co., Ltd. model numbers: 7282-5976 ASSY and 7283-5976 ASSY were used as connectors. This connector is tin-plated as a surface plating layer. The evaluation test results are shown in Tables 1 and 2.

  As shown in Table 1, in Examples 1 to 8, dioctyltin dilaurate was contained as the organotin compound, and there was no problem in electrical conductivity because fretting wear could be suppressed. It was found that no dynamic wear occurred.

  In addition, as shown in Example 5, if the organic tin compound is 0.01 parts by weight or more, the coating film thickness should be sufficiently ensured even if the organic solvent or the fluorine solvent as the non-flammable solvent is completely volatilized. Therefore, it was found that the effects (conductivity, insertion / extraction) due to the addition of the organotin compound are sufficient. In addition, in the solvent type, when 1.0 part by weight of the organic tin compound is added, the film thickness of the protective layer is about 1 μm to 10 μm, and when 0.01 part by weight of the organic tin compound is added, the film of the protective layer The thickness was about 0.01 μm to 1 μm. Incidentally, the film thickness of the protective layer in Example 1 was about 10 μm to 100 μm.

  Moreover, in Example 7 as a lubricating oil type, if the organotin compound was 0.01 parts by weight or more in the base oil, it was found that the effect of the addition of the organotin compound was sufficient. The same applies to the grease type.

  Reference Example 1 and Reference Example 2 contain an organotin compound, and it was found that the conductivity and insertion / extraction were slightly superior to those of the conventional example. Therefore, although the reference example 1 and the reference example 2 are also one of the examples, compared with Example 1-Example 8 mentioned above, it became a result in which electroconductivity and insertion / extraction property were inferior.

  This is because, in Reference Example 1, the content of the organotin compound is 0.005 parts by weight, and therefore, when the fluorine solvent as the organic solvent or the non-flammable solvent is completely volatilized, an appropriate coating film thickness is ensured. Due to not being able to.

  Similarly, also in Reference Example 2, the content of the organotin compound is 0.005 parts by weight, and the effect of the addition of the organotin compound can be achieved by having too little organotin compound contained in the lubricant. The expression was slightly insufficient.

  In addition, the conventional example is a commercially available protective agent, and unlike the examples, no organotin compound is prescribed, so it becomes non-conductive due to fretting wear, and sliding wear occurs in the insertion / extraction test. I found out that

  The surface protective agent for electrical contacts in the present invention can be used as a surface protective agent for electrical contacts configured with a material containing tin. In the present invention, for example, it can be used as a protective agent for tin-containing connectors used in automobiles, industrial machines, optical equipment, precision equipment and the like. In particular, it can be applied stably even in fields such as automobiles where the acceptance criteria for contact stability is very high.

1 Connector 2 Male Connector 3 Female Connector 5 Male Terminal (Connector Terminal)
7 Female terminal (connector terminal)
10 Substrate 11 Surface plating layer 12 Protective layer

Claims (15)

  A surface protective agent for an electrical contact comprising a material containing tin, the surface protective agent for an electrical contact comprising an organic tin compound.   The surface protective agent for an electrical contact according to claim 1, wherein the tin atom of the organic tin compound is in a state of 1 organic substituted tin, 2 organic substituted tin, or 4 organic substituted tin.   The organotin compounds include dimethyltin dilaurate, dibutyltin dilaurate, dioctyltin dilaurate, dimethyltin bis (dodecyl mercaptide), dibutyltin bis (dodecyl mercaptide), dioctyltin bis (dodecyl mercaptide), dimethyltin bis (thioglycolic acid) 2-ethylhexyl), dibutyltin bis (2-ethylhexyl thioglycolate), dioctyltin bis (2-ethylhexyl thioglycolate), dimethyltin diacetate, dibutyltin diacetate, dioctyltin diacetate, dimethyltin maleate, Dibutyltin maleate, dioctyltin maleate, dimethyltin bisthioglycerol, dibutyltin bisthioglycerol, dioctyltin bisthioglycerol, octyl 3. The electrical contact according to claim 1, wherein the electrical contact is selected from at least one of dutris (2-ethylhexyl thioglycolate) and bis (β-methoxycarbonylethyl) tin dilaurate. Surface protectant.   The surface for an electrical contact according to claim 3, wherein the organotin compound contains at least one of dioctyltin dilaurate, dioctyltin bis (2-ethylhexyl thioglycolate), and dioctyltin maleate. Protective agent.   The surface protective agent for an electrical contact according to any one of claims 1 to 4, comprising the organotin compound and a solvent.   The surface protective agent for an electrical contact according to claim 5, wherein the solvent is an organic solvent capable of making the organotin compound into a uniform solution.   The solvent is an aromatic hydrocarbon solvent, alcohol solvent, ester solvent, ether solvent, ketone solvent, glycol ether solvent, alicyclic hydrocarbon solvent, aliphatic hydrocarbon solvent, aliphatic or The surface protective agent for electrical contacts according to claim 6, wherein the surface protective agent is selected from at least one of aromatic hydrocarbon mixtures.   6. The surface protective agent for electrical contacts according to claim 5, wherein the solvent contains at least a fluorine solvent as a nonflammable solvent.   The fluorine solvent is hydrofluoroether, hydrofluorocarbon, hydrochlorofluorocarbon, perfluorocarbon, perfluoropolyether, benzotrifluoride, bis (trifluoromethyl) benzene, difluoroacetone, hydrofluoroolefin, and hydrochlorofluoroolefin. The surface protective agent for electrical contacts according to claim 8, wherein the surface protective agent is selected from at least one of them.   The surface protective agent for an electrical contact according to claim 9, wherein the fluorine solvent contains at least hydrochlorofluoroolefin.   The surface protective agent for an electrical contact according to any one of claims 1 to 4, comprising the organotin compound and a lubricating component of lubricating oil or grease.   The lubricating component is selected from at least one of mineral oil, synthetic hydrocarbon oil, diester oil, polyol ester oil, ether oil, glycol oil, silicone oil, and fluorine oil. The surface protective agent for electrical contacts according to claim 11.   Thickeners contained in the grease are lithium soap, calcium soap, sodium soap, aluminum soap, lithium composite soap, calcium composite soap, aluminum composite soap, urea compound, organic bentonite, polytetrafluoroethylene, silica gel, sodium terephthalate. The surface protective agent for an electrical contact according to claim 11 or 12, wherein the surface protective agent is selected from at least one of taramate. A contact configured with a tin-containing material;
A protective layer coated on the contact surface,
The said contact protection layer is formed using the surface protection agent for electrical contacts in any one of Claims 1-13, and contains the said organotin compound at least, The electrical contact characterized by the above-mentioned. A connector terminal comprising a material containing tin; and
A protective layer coated on the terminal surface;
The said protective layer is formed using the surface protective agent for electrical contacts in any one of Claims 1-13, and contains the said organotin compound at least, The connector characterized by the above-mentioned.

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