JP6355260B2 - Waterproof relay - Google Patents

Description

  The present invention relates to a waterproof relay excellent in waterproof function obtained by insert molding a thermoplastic resin using a metal terminal as an insert part, and a method for manufacturing the waterproof relay.

  For example, when street lights, electronic devices, communication devices, and the like are disposed outdoors, waterproof relays used for the electronic devices are those that have been waterproofed using a seal member or the like. In addition, when used in automobile applications, a waterproof function is also required in areas such as rain and water splashed from the road surface. Furthermore, depending on the place of use, it is necessary to maintain a waterproof function even in an environment where the temperature changes greatly.

  In general, when manufacturing a waterproof relay, after molding a thermoplastic resin housing mainly by injection molding, a method of inserting metal terminals by pinning and insert molding of thermoplastic resin and metal terminals is performed. The method is used. In particular, when manufactured by insert molding, in the injection molding process, because the thermoplastic resin is molded by pressing the metal terminal, it is difficult to leave a gap, high waterproof performance compared to the case of manufacturing by pinning, It is often used when a waterproof function is required.

  However, even when insert molding is performed by a normal method, depending on the type of thermoplastic resin and metal terminal, a large thermal stress is generated between the metal terminal and the thermoplastic resin due to the difference in the coefficient of linear expansion. May occur and a gap may be generated, preventing the waterproof function from being satisfied. Further, even when the waterproof function is satisfied immediately after molding, a gap is generated while the waterproof relay is used for a long period of time, and the function of the waterproof relay may be impaired due to water intrusion. As a result of analysis of this cause, repeated exposure to a high temperature environment and a low temperature environment during long-term use causes distortion between a metal terminal having a small linear expansion coefficient and a thermoplastic resin having a large linear expansion coefficient. It was found that a gap occurred. From the above, there is a problem that it is difficult to ensure a waterproof function when insert molding is performed by a normal method.

  In order to solve these problems, several methods are known as insert molding techniques in which adhesion between a metal terminal and a thermoplastic resin is improved to provide a waterproof function.

JP 2009-144198 A JP 2011-104787 A

For example, Patent Document 1 discloses a method of treating a metal surface to be inserted with a triazine thiol-based surface treatment agent in advance.
The triazine thiol-based surface treatment disclosed in Patent Document 1 forms an anodized film containing a triazine thiol derivative in advance on a metal surface. Then, a resin layer is formed on the anodic oxide film to improve the bonding between the resin layer and the metal via the anodic oxide film.

However, in order to form an anodic oxide film on the metal surface, electrodeposition is performed using an aqueous electrolyte solution containing a triazine thiol derivative as an electrodeposition solution, and after the electrodeposition, an unreacted triazine thiol derivative is removed. It needs to be washed away. In the cleaning after the electrodeposition of the anodized film, the management of the cleaning temperature becomes complicated in order to prevent the anodic oxide film from becoming hydrated.
Furthermore, in order to improve the adhesion between the anodic oxide film and the thermoplastic resin, it is necessary to shorten the time (open time) from the formation of the anodic oxide film to the insert molding. For this reason, when forming a waterproof relay by insert molding, it is necessary to carefully manage the time from surface treatment to the metal terminal that is the insert part until molding, so it is not suitable for small-lot, high-mix production. .

Furthermore, in Patent Document 2, adhesion is improved by performing insert molding using a mold in which a heat insulating layer made of a material having high heat insulating properties such as polyimide is formed on the surface of the mold surface that comes into contact with the metal component. A method is disclosed.
In the insert molding method disclosed in Patent Document 2, by forming a heat insulating layer on the mold surface, high-temperature molten resin flows into the mold and the temperature of the metal parts in the mold rapidly increases. The temperature of the metal part and the part of the resin that comes into contact with the metal part is made difficult to decrease, and the difference in shrinkage between the resin and the metal part is reduced to increase the adhesion. However, this method cannot accurately form a heat insulating layer for all product shapes, so that it is difficult to cope with complicated product shapes, and there is a problem that the product shapes are limited.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to prevent the gap between the metal terminal and the thermoplastic resin from being generated even in a temperature environment where the operating temperature range is wide, and to open after the surface treatment. The purpose of the present invention is to provide a waterproof relay with a high waterproof function that can perform insert molding without being restricted by the production process for a long time.

  In order to solve the above-mentioned problems, the present inventor insert-molded a metal terminal having an adhesion layer made of a chlorosulfonated polyethylene composition, so that the chlorosulfonated polyethylene composition is firmly bonded to the metal terminal and the thermoplastic resin. As a result, it was found that high adhesion was obtained, and this adhesion layer prevented the ingress of water, and that the waterproof relay made by this method worked normally for a long time even in a high humidity environment. Furthermore, it has been found that this waterproof relay has an excellent waterproof function.

That is, the present invention provides the following.
A waterproof relay in which a part of the metal terminal according to claim 1 is covered with a base made of a thermoplastic resin, wherein an adhesion layer made of a chlorosulfonated polyethylene composition is formed on a portion of the metal terminal covered by the base, It is a waterproof relay characterized by having an adhesion layer between the terminal and the base,
As a method of joining the metal terminal and the base according to claim 2, a waterproof relay manufacturing method using a method of placing a metal terminal in an insert molding die, clamping the mold and insert molding a thermoplastic resin in a cavity. Then, before insert molding, an adhesive layer made of a chlorosulfonated polyethylene composition is formed in advance on the portion of the metal terminal covered by the base, and the metal terminal is attached to the insert molding die so that the adhesive layer is placed in the cavity. And a waterproof relay manufacturing method characterized by performing insert molding,
The waterproof relay manufacturing method according to claim 3, wherein the chlorosulfonated polyethylene composition is previously made into a solution using an organic solvent, and the base of the metal terminal covers the solution of the chlorosulfonated polyethylene composition. A method for producing a waterproof relay, wherein the adhesive layer is formed by applying the coating to the substrate and then drying.
Here, the portion covered by the housing is a portion where the terminal portion of the fixed contact is fixed by the housing, and indicates a portion where the outer peripheral portion of the terminal portion is embedded in the housing.

  According to the invention, the adhesion layer comprises a chlorosulfonated polyethylene composition. Since this chlorosulfonated polyethylene is a synthetic rubber excellent in heat resistance and cold resistance, the adhesion layer made of a chlorosulfonated polyethylene composition that has elasticity even in a usage environment with a wide operating temperature range is a wire between a metal terminal and a thermoplastic resin. It is possible to provide a waterproof relay having a high waterproof function by absorbing a strain due to a difference in expansion coefficient and preventing a gap from being generated.

It is sectional drawing which shows the waterproof relay of embodiment of this invention.

  Hereinafter, an example of an embodiment of a waterproof relay according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the waterproof relay 1 of this embodiment includes a thermoplastic resin base 2 formed by insert molding of a metal terminal 3, a fixed contact 5 fixed to the metal terminal 3, and an electromagnet 6. It is comprised from the resin-made sealing case 9 welded to the said base 2 so that the movable contact 8 attached to the front-end | tip part of the movable movable contact piece 7 may be surrounded. An adhesion layer 4 is formed on the portion of the metal terminal 3 that is covered with the base 2.

  As shown in FIG. 1, the metal terminal 3 used in the present embodiment is a long plate. The metal terminal 3 used may have any shape such as a square shape, a round shape, a simple plate shape, or a complicated bent shape, depending on the purpose of use. The material is a conductive metal material such as copper or a copper alloy. Furthermore, depending on the purpose of use, nickel-base gold plating, tin plating, nickel plating, or the like may be applied. An intermediate portion of the metal terminal 3 is embedded in the base 2 and both end portions of the metal terminal 3 are exposed.

  In the metal terminal 3 used in the present embodiment, the adhesion layer 4 is formed in advance on the portion covered with the base 2 before injection molding. The adhesion layer of the present invention may be in a state where the end portion thereof protrudes from the base 2, or may be positioned inward of the base 2 and covered with the base 2. In any case, the metal terminal 3 and the base 2 adhere to the adhesion layer 4 well.

  The adhesion layer 4 used in the present embodiment is formed from a CSM composition that is a mixture of chlorosulfonated polyethylene (hereinafter referred to as CSM) and additives such as a vulcanizing agent, a vulcanization accelerator, and an acid acceptor. It is a membrane. Furthermore, the CSM composition is an anti-oxidant, anti-aging agent, filler, processing aid, softener, and wettability improver that improves the wettability to resin / metal conductors in order to make CSM performance work effectively. Etc. are added as necessary.

  The chlorosulfonated polyethylene used in this embodiment is polyethylene, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-ethyl acrylate copolymer, ethylene- It is made into a rubber by reacting a methyl acrylate copolymer or the like with chlorine and sulfurous acid gas to carry out chlorination and chlorosulfonation.

  Examples of the vulcanizing agent used in the present embodiment include magnesium oxide, maleimide compounds such as N, N′-m-phenylene dimaleimide, and organic oxides such as dicumyl peroxide.

  Examples of the vulcanization accelerator used in this embodiment include thiuram compounds such as dipentamethylene thiuram disulfide, tetramethyl thiuram disulfide, and tetraethyl thiuram disulfide, and 6-ethoxy-1,2-dihydro-2,2,2. , 4-trimethylquinoline, dibutyldithiocarbamic acid, 2-mercaptobenzimidazole, and the like can be used.

  Examples of the acid acceptor used in the present embodiment include metal oxides such as magnesium oxide, calcium oxide, calcium hydroxide, and magnesium hydroxide, metal hydroxides, hydrotalcite, and the like.

  The adhesion layer 4 used in the present embodiment is formed by applying an organic solution obtained by dissolving the CSM composition in an organic solvent to the above-described position of the metal terminal 3 and drying it. Into an organic solvent, the CSM composition is added and stirred until homogeneous to make an organic solution. Further, a kneading step of the CSM composition may be added in order to dissolve it uniformly.

As the organic solvent for dissolving CSM, an inert organic solvent that is soluble in CSM is used. Specifically, for example, toluene, xylene, methylene chloride, carbon tetrachloride, trichloroethylene, methyl ethyl ketone, and the like can be used.

  In order to mix CSM, vulcanizing agent, vulcanization accelerator, acid acceptor and antioxidant more homogeneously, CSM and additive are pre-mixed in roll kneader, kneader, Banbury mixer, etc. Knead until mixed to make a CSM composition solid. When this CSM composition solid is dissolved in an organic solvent, a more homogeneous organic solution can be prepared.

  The application method of the organic solution is not limited as long as the metal terminal 3 can be applied to the portion covered with the base 2, and the application method such as the brush coating method, the air brush method, the dipping method, or the pad Coating methods such as printing methods, silk printing, and printing methods such as inkjet printing can be used. In addition, it is desirable to secure a target film thickness by a single application, but it may be applied a plurality of times if a uniform film thickness or a thick film is required. In the case where the adhesion layer 4 is formed by painting, the adhesion layer 4 can be accurately formed only in necessary portions by masking and painting the portion of the metal terminal 3 where the adhesion layer 4 is not formed. Furthermore, regarding the application region, it is sufficient that the waterproof function can be satisfied, whether it is the entire part embedded in the base 2 or a part thereof.

  The drying method of the adhesion layer 4 is appropriately selected from natural drying and heat drying, and the drying time is not limited as long as the organic solvent evaporates, but is performed under drying conditions that do not cause vulcanization of the CSM composition. Further, the dried metal terminal 3 may be stored for a long period of time as long as the adhesion layer 4 is not vulcanized.

  The film thickness of the adhesion layer 4 used in the present embodiment depends on the method of inserting the metal terminal 3 into the base 2, the shape of the metal terminal 3, the difference in the linear expansion coefficient between the metal terminal 3 used and the thermoplastic resin, and the like. Although it is necessary to select suitably, the range of 5 micrometers or more and 100 micrometers or less is preferable. When the adhesion layer is thin, the adhesion effect is low when the temperature range is wide, and the waterproof effect cannot be sufficiently maintained. On the other hand, if the film thickness is thick, the adhesion layer is washed away in the insert molding process, and the washed adhesion layer becomes a foreign matter or causes mold contamination. More preferably, if it is 10 μm or more and 60 μm or less, it is possible to form the adhesion layer 4 of a film that keeps the waterproof function good and is not washed away during insert molding.

  The concentration of the organic solution varies depending on the organic solvent to be used, the coating method on the metal terminal 3, and the target film thickness, but the CSM composition is 10 to 70 parts by weight with respect to 100 parts by weight of the organic solvent. The concentration of the organic solution is adjusted within the range. When the concentration of the CSM composition in the organic solution is less than 10 parts by weight, the film thickness of the adhesion layer becomes thin, and when the temperature range is wide, the adhesion effect is small and the waterproof effect is low. On the other hand, if the concentration of the CSM composition in the organic solution is higher than 70 parts by weight, the film thickness becomes too thick, which causes foreign matter and mold contamination, which is not preferable. Therefore, when the organic solution is applied by a coating process, the concentration of the CSM composition in the organic solution is preferably adjusted to 30 to 70 parts by weight with respect to 100 parts by weight of the organic solvent. Moreover, when apply | coating an organic solution by a printing process, the density | concentration of the CSM composition of an organic solution can adjust CSM composition in the range of 10 to 50 weight part with respect to 100 weight part of organic solvents. preferable.

  As the thermoplastic resin used for forming the base 2 used in the present embodiment, a resin used in a normal injection molding method is selected. In particular, polyphenylene sulfide resin, liquid crystal polymer, polybutylene terephthalate resin, and nylon resin are preferable because they have high dimensional accuracy and high heat resistance.

  The injection mold used in the present embodiment is a general mold for insert molding having a cavity portion into which a molten and liquefied thermoplastic resin is injected and a space in which a metal terminal is held. The metal terminal on which the adhesion layer of the CSM composition is formed is placed in the above-described injection mold, and insert molding is performed using a general injection molding machine.

  Since the adhesion layer 4 made of the CSM composition adheres well to the melted resin, the waterproof relay 1 in which the metal terminal 3 and the base 2 are adhered through the adhesion layer 4 is obtained.

  As described above, since the waterproof relay 1 according to the present embodiment forms the adhesion layer 4 between the base 2 and the metal terminal 3, the adhesion layer is formed by connecting the thermoplastic resin constituting the base 2 and the metal terminal 3 to each other. By using 4, good adhesion can be achieved. As a result, the base 2 and the metal terminal 3 of the waterproof relay 1 have good adhesion even when used for a long time via the adhesion layer 4, and a reliable waterproof function is obtained.

  The waterproof relay and the manufacturing method thereof according to the present invention are not limited to the embodiment described with reference to the above description and drawings, and various modifications can be made within the scope of the present invention.

  The waterproof relay of the present invention can be favorably used in fields where waterproofing is mainly required, such as electronic devices used outdoors and in-vehicle parts.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited at all by this.

Manufacturing example (metal terminal)
The metal terminal 3 used for the present Example and the comparative example used the copper which performed the tin plating process.

(CSM composition creation)
For 100 parts by weight of chlorosulfonated polyethylene (TOSO-CSM (registered trademark) CM-1500: manufactured by Tosoh Corporation),
4 parts by weight of magnesium oxide (Kyowa Mag 150 (registered trademark): manufactured by Kyowa Chemical Industry Co., Ltd.) as a vulcanizing agent and an acid receiving material
2 parts by weight of dipentamethylene thiuram tetrasulfide (Noxeller (registered trademark) TRA: manufactured by Ouchi Shinsei Chemical Co., Ltd.) as a vulcanization accelerator,
CSM composition by adding 3 parts by weight of pentaerythritol (Neuiser (registered trademark) P: manufactured by Nippon Synthetic Chemical Co., Ltd.) as an antioxidant and kneading for 15 minutes with a roll kneader at a processing temperature of 80 ° C. I got a thing.

(Creation of organic solution)
With respect to 100 parts by weight of toluene (manufactured by Wako Pure Chemical Industries, Ltd., Grade 1), the CSM composition was added in a proportion of 40 parts by weight, and stirred for 4 hours using a stirrer to obtain an organic solution.

(Formation of adhesion layer)
The organic solution was applied to the metal terminal 3 by brushing and naturally dried for 16 hours in an environment at room temperature of 25 ° C. to obtain the adhesion layer 4. When the film thickness was measured after drying, it was 15 to 30 μm.

(Molding material)
Commercially available polyphenylene sulfide (hereinafter referred to as PPS resin) and polybutylene terephthalate (hereinafter referred to as PBT resin) are prepared as molding materials for forming the insert molded product 1 ′ used in the examples and comparative examples. What was dried for 3 hours or more with a dryer at 0 ° C. was used. Each product name is described in Table 1.

(Insert molding)
A base 2 shown in FIG. 1 was produced by insert molding using an injection molding machine and a mold (not shown). Main molding conditions are shown in Table 1. Then, as shown in FIG. 1, the general waterproof relay 1 was assembled and evaluated by the following evaluation method.

Evaluation method (Evaluation of waterproof function of insert molded products)
The obtained waterproof relay 1 was stored at room temperature for 1 day and then submerged in water at a depth of 1 m for 30 minutes. Then, operation check was performed and the presence or absence of a malfunction was confirmed.

(Evaluation of waterproof function after heat cycle test)
The obtained waterproof relay 1 was stored at room temperature for 1 day, and then a heat cycle test was performed under the temperature environment shown in Table 1. Thereafter, the waterproof relay 1 ′ was evaluated by the same method as the waterproof function evaluation.

[Example 1]
The organic solution was applied to the metal terminal 3 and dried to obtain the adhesion layer 4. The waterproof relay 1 was obtained by insert-molding the metal terminal 3 on which the adhesion layer 4 was formed using the PPS resin shown in Table 1 under the injection molding conditions shown in Table 1. When 110 waterproof relays obtained were evaluated for waterproof function, no malfunction was confirmed. Furthermore, when a waterproof function evaluation was performed on 110 waterproof relays after the heat cycle test, no malfunction was confirmed. According to Example 1, the waterproof relay 1 obtained by insert-molding the PPS resin into the metal terminal 3 formed of the CSM composition as the adhesion layer 4 has a good adhesion state between the metal terminal 3 and the base 2, and has a waterproof function. It was confirmed to have

[Example 2]
The waterproof relay 1 was molded in the same manner as in Example 1 except that the resin to be insert-molded was changed to PBT resin. When 110 waterproof relays obtained were evaluated for waterproof function, no malfunction was confirmed. Furthermore, when a waterproof function evaluation was performed on 110 waterproof relays after the heat cycle test, no malfunction was confirmed. According to Example 2, the waterproof relay 1 obtained by insert molding the PBT resin to the metal terminal 3 formed with the CSM composition as the adhesion layer 4 has a good adhesion state between the metal terminal and the base 2 and has a waterproof function. It was confirmed.

[Comparative Example 1]
The waterproof relay 1 was obtained by insert-molding PPS resin into the metal terminal 3 on which the adhesion layer 4 was not formed. When 110 waterproof relays obtained were evaluated for waterproof function, no malfunction was confirmed. Further, when 110 waterproof relays after the heat cycle test were evaluated for waterproof function, 3 out of 10 malfunctions were confirmed. According to Comparative Example 1, the waterproof relay 1 obtained by insert-molding PPS resin on the metal terminal 3 on which the adhesion layer 4 is not formed is deteriorated in adhesion due to repeated exposure to a high temperature environment and a low temperature environment. It was confirmed that the function was impaired.

[Comparative Example 2]
The waterproof relay 1 was obtained by insert-molding PBT resin into the metal terminal 3 on which the adhesion layer 4 was not formed. When 110 waterproof relays obtained were evaluated for waterproof function, no malfunction was confirmed. Furthermore, when the waterproof function evaluation was performed on 110 waterproof relays after the heat cycle test, 2 out of 10 malfunctions were confirmed. According to Comparative Example 2, the waterproof relay 1 obtained by insert-molding PBT resin on the metal terminal 3 on which the adhesion layer 4 is not formed is deteriorated in the adhesion state due to repeated exposure to a high temperature environment and a low temperature environment. It was confirmed that the function was impaired.

Table 2 shows the evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2.

  From the results of the above examples and comparative examples, by providing an adhesion layer made of a chlorosulfonated polyethylene composition between the metal terminal and the base, the waterproofing is ensured over a long period of time in a use environment where waterproofing is required. It was confirmed that an insert molded product capable of obtaining the function was created. By forming the CSM composition as an adhesive layer, it was confirmed that there was an excellent adhesive improvement effect during insert molding using PPS resin and PBT resin as molding resin.

DESCRIPTION OF SYMBOLS 1 Waterproof relay 2 Base 3 Metal terminal 4 Adhesion layer 5 Fixed contact 6 Electromagnet 7 Movable contact piece 8 Movable contact 9 Adhesion case

Claims (3)

A waterproof relay in which a part of a metal terminal is covered with a thermoplastic resin base,
A waterproof relay, wherein an adhesive layer made of a chlorosulfonated polyethylene composition is formed on a portion of a metal terminal covered by a base, and the adhesive layer is provided between the metal terminal and the base. As a method of joining the metal terminal and the base, a method for manufacturing a waterproof relay using a method of placing a metal terminal in an insert molding die, clamping the mold and insert molding a thermoplastic resin in a cavity,
Prior to insert molding, an adhesive layer made of a chlorosulfonated polyethylene composition is formed in advance on the portion of the metal terminal covered by the base, and the metal terminal is attached to the insert molding die so that the adhesive layer is disposed in the cavity. A method for manufacturing a waterproof relay, characterized in that molding is performed. In the manufacturing method of the waterproof relay according to claim 2,
Waterproofing characterized in that a chlorosulfonated polyethylene composition is preliminarily made into a solution using an organic solvent, the solution of the chlorosulfonated polyethylene composition is applied to the portion of the metal terminal covered by the base, and then dried to form an adhesion layer. Relay manufacturing method.