JP7223179B2 - Wire with terminal - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric wire with a terminal using a coating material used for anticorrosion of automobile parts, for example.

2. Description of the Related Art Conventionally, in the fields of automobiles, OA equipment, home electric appliances, and the like, electric wires made of copper-based materials with excellent electrical conductivity have been used as power lines and signal lines. In particular, in the field of automobiles, the performance and functionality of vehicles are rapidly advancing, and the number of various electric devices and control devices to be mounted on vehicles is increasing. Therefore, along with this, the number of electric wires with terminals used tends to increase.

On the other hand, while environmental problems are attracting attention, there is a demand for weight reduction of automobiles. Therefore, an increase in weight due to an increase in the amount of use of the wire harness becomes a problem. For this reason, light weight aluminum wires have attracted attention in place of conventionally used copper wires.

Here, a connection terminal is used when connecting such electric wires or at a connection portion of equipment. However, even in an electric wire with a terminal using an aluminum electric wire, there are cases where copper, which has excellent electrical properties, is used for the terminal portion for the reliability of the connecting portion. In such a case, an aluminum electric wire and a copper terminal are joined and used.

However, when dissimilar metals are brought into contact with each other, so-called electrolytic corrosion may occur due to the difference in standard electrode potential. In particular, since the standard electrode potential difference between aluminum and copper is large, corrosion on the electrically base aluminum side progresses due to the influence of water splashing and condensation on the contact portion. As a result, the connection between the wire and the terminal at the connection part becomes unstable, and there is a risk of an increase in contact resistance, an increase in electrical resistance due to a decrease in wire diameter, and even a disconnection, which may lead to malfunction or stoppage of electrical components. be.

For this reason, a method has been proposed in which the connecting portion between the electric wire and the terminal is covered with a resin member. For example, an electric wire with a terminal has been proposed in which a conductor exposed between a covering crimping portion and a conductor crimping portion is coated with a resin member and covered (Patent Document 1).

FIG. 5 is a partial cross-sectional view of a conventional terminal-equipped electric wire. Usually, the covering portion 115 is removed near the tip of the covered conductor wire 111 to expose the conductor wire 103 inside. The exposed conductor 103 is crimped by the conductor crimping portion 107 and the covering portion 115 is crimped by the covering crimping portion 109 . Since part of the conductor wire 103 is exposed in the inter-barrel portion 108 between the cover crimp portion 109 and the conductor crimp portion 107 , the resin member 117 covers the conductor crimp portion 107 from the inter-barrel portion 108 .

However, a minute gap (X in the drawing) is likely to occur at the boundary between the end of the covering portion 115 and the exposed portion of the conductor 103 due to the change in outer diameter. If such a gap occurs, there is a risk that moisture that has permeated between the covering crimping portion 109 and the covering portion 115 will permeate the conductor wire 103 and the conductor crimping portion 107 . Therefore, in order to ensure sufficient anti-corrosion properties, it is necessary to allow the resin member 117 to permeate the gap X and harden it.

As a method of filling the gap X with the resin member 117, for example, there is a method of adjusting the viscosity of the resin member 117 during application. However, even if the gap X can be filled with the resin member 117, there is a problem that the ultraviolet rays do not reach the back side of the conducting wire 103 when irradiated with the ultraviolet rays, and it takes time to harden.

Thus, as a method for curing the deep part of the crimped portion of the conductor, a chain transfer agent composed of an ultraviolet curable material, a compound containing at least one selected from urethane bonds, urea bonds, and isocyanate groups, and a metal-containing compound is proposed (for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2017-102998 JP 2011-123281 A

However, in the method of Patent Document 2, since a metal-containing compound is added as a chain transfer agent, there is a problem that the metal-containing compound absorbs ultraviolet rays. Therefore, there is a problem that the ultraviolet irradiation time for curing becomes long.

In particular, when a resin member is applied to an electric wire with a terminal and cured, it is desirable that the applied resin member is visible. This is for visually confirming whether or not the conductive wire is surely covered with the resin member. Therefore, in some cases, a colored resin member is used instead of a completely transparent resin member. However, when the resin member is colored in order to improve visibility in this way, there is a problem that ultraviolet rays are less likely to reach deep areas.

The present invention has been made in view of such problems, and even if it is used in a colored form, it is possible to shorten the curing time of the resin in the deep part without using a metal-containing compound. An object of the present invention is to provide an electric wire with a terminal using a material.

In order to achieve the above object, the present invention provides a resin film structure in which a coating material is applied to a member to be coated and cured, wherein the member to be coated is an electric wire with a terminal in which a coated conductor and a terminal are connected. The coated conductor includes a coated portion and a conductive wire exposed from the tip of the coated portion, the terminal has a terminal body and a crimping portion, and the crimping portion is crimped onto the conductive wire. A conducting wire crimping portion, a covering crimping portion to which the covering portion is crimped, and an inter-barrel portion between the conducting wire crimping portion and the covering crimping portion, at least from the inter-barrel portion to the conducting wire crimping portion. The portion where the conductor wire is exposed is covered with the coating material, and the coating material includes a resin base material and a photoreaction initiator added thereto, and the photoreaction initiator absorbs light in the ultraviolet region. It comprises an aminoketone-based first photoinitiator that generates radicals upon irradiation and a second photoinitiator that has photobleaching properties with respect to light in the ultraviolet region, wherein the first photoinitiator is Radicals are generated by irradiation with light in a wavelength range of 365 nm to 405 nm, and the second photoinitiator contains at least one of an acylphosphine oxide photoinitiator and an oxime ester photoinitiator. An electric wire with a terminal characterized by:

For the coating material, the coloring pigment or dye is selected from cyanine compounds, phthalocyanine compounds, naphthoquinone compounds, diimmonium compounds, naphthalocyanine compounds, squalium dyes, quinone compounds, azo compounds, quinacridones, dioxane, benzimidazolones, and carbon black. It is desirable to contain one or a combination of two or more.

The aminoketone-based first photoinitiators include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholino Linophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone.

The acylphosphine oxide photoinitiator is selected from bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the oxime ester System photoinitiators are 1,2-octanedione, 1-[4-(phenylthio)-, 2-(0-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl )-9H-carbazol-3-yl]-, 1-(0-acetyloxime).

The base resin of the coating material is modified acrylate, and may further contain one or two selected from moisture-curable silicon-modified acrylate and thermosetting epoxy-modified acrylate.

The difference in the curing reaction rate calculated based on infrared light absorption between the coating material on the surface portion in the inter-barrel portion and the coating material on the bottom surface side of the terminal on the back side of the conductor is within 3%. desirable.

ADVANTAGE OF THE INVENTION According to this invention, the electric wire with a terminal which the coating material was apply|coated to the lower part of the conducting wire, and was hardened can be obtained. In addition, the photoinitiator contains an aminoketone-based first photoinitiator, and the photoinitiator contains a second photoinitiator having photobleaching properties. can reduce the absorbance of the resin that has started, and even if the coating material is colored, light can reach deeper and curing can proceed. Therefore, the coating material can be hardened to a deep portion in a short time.

In addition, the first photoreaction initiator generates radicals when irradiated with light in the wavelength region of 365 nm to 405 nm, so that the coating material can be reliably cured by irradiation with light in the ultraviolet region.

Further, the second photoinitiator contains at least one of an acylphosphine oxide-based photoinitiator and an oxime ester-based photoinitiator, so that the photobleaching property is more assured at a wavelength around 365 to 380 nm. can be demonstrated.

In addition, if the difference in the curing reaction rate calculated based on infrared light absorption between the coating material on the surface part in the inter-barrel part and the coating material on the bottom side of the terminal on the back side of the conductor is within 3%, the coating material Since the difference in curing reaction rate between the surface and the deep part of the coating is small, it is possible to suppress deterioration of the coating material in the thermal shock test.

According to the present invention, there is provided an electric wire with a terminal using a coating material capable of shortening the hardening time of the deep resin without using a metal-containing compound, even when used in a colored state. be able to.

The perspective view which shows the electric wire 10 with a terminal. Sectional drawing which shows the electric wire 10 with a terminal. The figure which shows the terminal 1 and the covered conductor 11 before crimping. The figure which shows the positive pressure test method of the electric wire 10 with a terminal. Partial sectional view of the conventional electric wire with a terminal.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an electric wire 10 with a terminal, and FIG. 2 is a cross-sectional view. 1 is a perspective view of the coating material 17. FIG. A terminal-equipped electric wire 10 is configured by connecting a terminal 1 and a coated conductor 11 .

Covered lead wire 11 includes lead wire 13 made of aluminum or an aluminum alloy and cover portion 15 covering lead wire 13 . That is, the covered conductor wire 11 includes a covered portion 15 and the conductor wire 13 exposed from the tip thereof. The conducting wire 13 is, for example, a twisted wire in which a plurality of wires are twisted together.

The terminal 1 is of open barrel type and made of copper or copper alloy. A coated conductor 11 is connected to the terminal 1 . The terminal 1 is configured by connecting a terminal main body 3 and a crimping portion 5 via a transition portion 4 . The transition portion 4 positioned between the crimping portion 5 and the terminal body 3 is open at the top.

The terminal main body 3 is formed by forming a plate-shaped material having a predetermined shape into a tubular body having a rectangular cross section. The terminal body 3 has an elastic contact piece inside which is formed by folding a plate-like material into a rectangular cylindrical body. The terminal body 3 is connected by inserting a male terminal or the like from the front end portion. In the following description, an example in which the terminal body 3 is a female terminal that allows insertion of an insertion tab (not shown) of a male terminal or the like will be shown. is not particularly limited. For example, an insertion tab for a male terminal may be provided instead of the female terminal main body 3 .

The crimping part 5 is a part to be crimped with the coated conductor 11, and has a substantially U-shaped cross-sectional shape perpendicular to the longitudinal direction of the terminal 1 before crimping. The crimping portion 5 of the terminal 1 includes a conductor crimping portion 7 for crimping the conductor wire 13 exposed from the covering portion 15 to the distal end side of the covered conductor 11, a covering crimping portion 9 for crimping the covering portion 15 of the covered conductor 11, and a conductor crimping portion. It consists of an inter-barrel portion 8 between the portion 7 and the covering crimp portion 9 .

A portion of the inner surface of the conductor crimping portion 7 is provided with serrations (not shown) in the width direction (direction perpendicular to the longitudinal direction). By forming the serrations in this manner, the oxide film on the surface of the conductor 13 is easily destroyed when the conductor 13 is crimped, and the contact area with the conductor 13 can be increased.

At the tip of the covered conductor 11, the covering portion 15 is peeled off, and the conductor 13 inside is exposed. The covering portion 15 of the covered conductor wire 11 is crimped by the covering crimping portion 9 of the terminal 1 . Further, the conductor wire 13 exposed by peeling off the covering portion 15 is crimped by the conductor crimping portion 7 . The conductor wire 13 and the terminal 1 are electrically connected at the conductor crimping portion 7 . The end face of the covering portion 15 is located in the inter-barrel portion 8 between the covering crimping portion 9 and the conductor crimping portion 7 .

In the present invention, at least the portion where the conductor wire 13 is exposed from the inter-barrel portion 8 to the conductor crimping portion 7 is covered with the coating material 17 . That is, at least the portion where the conductor wire 13 is exposed from the inter-barrel portion 8 to the conductor crimping portion 7 is covered with the coating material 17, and the conductor wire 13 is not exposed to the outside by the coating material 17. The coating material 17 functions as an anti-corrosion material, and forms a resin coating structure by applying the coating material 17 to an electric wire with a terminal, which is a member to be coated, and curing the coating material.

Here, the coating material 17 is formed by adding a photoreaction initiator to a base material resin containing necessary components among oligomers, diluent monomers, polyols, and silane coupling agents. That is, the coating material 17 has ultraviolet curing properties. The coating material 17 of the present invention contains at least two types of photoreaction initiators: a first aminoketone-based photoreaction initiator that generates radicals when irradiated with light in the ultraviolet region; and a second photoinitiator having photobleaching properties with respect to light. Note that the coating material 17 of the present invention does not contain a metal-containing compound (metal salt or metal complex). Moreover, the coating material 17 may contain additives such as sensitizers, pigments, dyes, and lubricants.

The aminoketone-based photoreaction initiator of the first photoreaction initiator generates radicals upon irradiation with light in the wavelength region of 365 nm to 405 nm. Aminoketone-based photoreaction initiators are less susceptible to curability even when curing an ultraviolet curable resin containing pigments or dyes for visibility. Therefore, even when the coating material 17, which is not completely colorless and transparent, is applied to the terminal-equipped wire, it can be hardened to a deep portion, and it is possible to easily grasp whether or not the coating material 17 is applied by coloring. .

Furthermore, it is desirable to include a thioxanthone-based sensitizer that enhances radical generation at 365 nm to 405 nm by being excited by light in the ultraviolet region and donating electrons to the first photoreaction initiator. An aminoketone-based photoreaction initiator shifts the absorption wavelength to the longer wavelength side by mixing with a thioxanthone-based sensitizer. That is, it can be cured by a light source with a longer wavelength. Since light from a long-wavelength light source easily reaches a deep part, curability can be further improved by using, for example, a 385 nm light source, a 405 nm light source, or a light source containing both.

The second photoinitiator preferably contains at least one of an acylphosphine oxide photoinitiator and an oxime ester photoinitiator. Both acylphosphine oxide-based photoinitiators and oxime ester-based photoinitiators have photobleaching properties near 380 nm, and light transmittance is improved by irradiating with light of this wavelength. .

Note that photobleaching, also written as photobleaching or photobleaching, is one of the environmental effects and refers to a photochemical property rarely seen in excited fluorescent molecules. This reaction occurs because the fluorescent substance in the excited state is chemically activated and becomes unstable compared to the ground state. As a result of this reaction, it means that the fluorescent molecule finally changes into a low-fluorescent structure. In the invention according to the present embodiment, when the photoreaction initiator absorbs light in a certain ultraviolet region and generates radicals to initiate polymerization in the ultraviolet curable resin, the molecules of the photoreaction initiator after radical generation are Photobleaching refers to the breaking of conjugate bonds and the reduction in absorbance in the ultraviolet region. As a result, light in the ultraviolet range can be transmitted to the inside, so that even a thick film can be cured smoothly.

As the α-aminoketone-based photoreaction initiator, for example, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, which has a strong absorption peak at 260 to 340 nm, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1- with an absorption peak at 400 nm [4-(4-morpholinyl)phenyl]-1-butanone can be mentioned. Commercially available products include IRGACURE907, IRGACURE369, and IRGACURE379 (all trade names, manufactured by BASF).

In addition, the 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (907), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone- 1(369), 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (379) and a thioxanthone sensitizer As, by using 2,4-diethylthioxanthone (commercially available, Kayacure DETX-S (trade name, manufactured by Nippon Kayaku Co., Ltd.)) with absorption at 260 to 410 nm, the absorption coefficient (ε) at 405 nm is higher, contributes to deeper curing, and can be reacted more efficiently.

Acylphosphine oxide-based photoreaction initiators include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. Commercially available products include Lucirin-TPO, DAROCUR-TPO and IRGACURE819 (all trade names, manufactured by BASF).

Since these photoinitiators have a strong absorption peak at 260 to 440 nm, the LED wavelengths of 385 nm and 395 nm are more effective than 365 nm. Furthermore, the acylphosphine oxide-based photoreaction initiator exhibits a photobleaching effect in which absorption disappears due to decomposition, so that not only the surface cure but also the depth of the cure can be increased. That is, although the acylphosphine oxide photoreaction initiator has absorption in the long wavelength region (near 385 nm) at the start of irradiation with ultraviolet rays, the absorption in the long wavelength region disappears as the photopolymerization reaction progresses. Therefore, when the photopolymerization reaction progresses, the ultraviolet rays reach the deep part, and the degree of curing in the deep part can be increased.

The following coloring pigments and dyes can be used. Cyanine compounds, phthalocyanine compounds, naphthoquinone compounds, diimmonium compounds, naphthalocyanine compounds, squalium dyes, quinone compounds, azo compounds, quinacridones, dioxane, benzimidazolones, carbon black and the like can be used. These components may be used individually by 1 type, and may be used in combination of 2 or more type. Photoreaction initiators effective for hardening deep portions from the surface of the colored ultraviolet curable resin include, for example, α-aminoketone photoreaction initiators and acylphosphine oxide photoreaction initiators. As described above, the addition of an α-aminoketone-based photoreaction initiator and a thioxanthone-based sensitizer having an absorption peak in the long wavelength range increases the absorption peak in the long wavelength range (especially 405 nm as described above). Furthermore, by combining an acylphosphine oxide-based photoreaction initiator, the degree of curing on the surface and inside can be efficiently increased.

Further, oxime ester-based photoreaction initiators include 1.2-octanedione, 1-[4-(phenylthio)-, 2-(0-benzoyloxime)], ethanone, 1-[9-ethyl-6 -(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime). Commercially available products include IRGACURE OXE01 and IRGACURE OXE02 (both trade names, manufactured by BASF), and IRGACURE OXE01 (trade name, manufactured by BASF) has photobleaching properties.

In this way, by adding a thioxanthone-based sensitizer to an α-aminoketone-based photoreaction initiator that is effective for curing deep portions from the surface of a colored UV-curable resin, ) can be increased, and by using photobleaching in combination with a photoreaction initiator such as acylphosphine oxide, curing starts from the surface irradiated with light, and at the cured site , the transmittance increases, so that the light reaches a deeper portion, and the coating material 17 can be cured in a short time.

As mentioned above, the main reaction of UV-curable resins is radical polymerization, and the radicals generated by decomposition of the photoreaction initiator under the action of UV rays attack the double bonds of the modified acrylate, initiating radical polymerization. be done. The base resin is modified acrylate, and acrylic groups are added to both ends of the main chain of epoxy, polyester, urethane, etc. The acrylic groups become reactive groups that are polymerized by ultraviolet rays. In addition, by imparting other functions of the modified acrylate, which is the main component of the UV-curable resin, it is possible to cure the part where the UV rays are difficult to reach at the same time as the UV irradiation or during the process. For example, modified acrylates can impart UV-curability, moisture-curability, heat-curability, and anaerobic-curability, respectively. Deep part curability can be imparted by imparting both properties of ultraviolet curing and moisture curing or anaerobic curing in a well-balanced manner.

For example, for moisture curing, silicon-modified acrylate is preferably used, and after UV curing is completed, it can be further cured by moisture. In addition, thermosetting is achieved by using thermosetting epoxy-modified acrylate together. By irradiating with ultraviolet rays, the surface of the resin, which is difficult to thermoset, is cured. Can be cured. As for anaerobic curing, curing is completed relatively quickly under the condition that metal ions intervene, because anaerobic curing is accelerated by the heat of irradiation during curing by ultraviolet rays, and air is blocked at the surface portion by ultraviolet curing.

The amount of the photoreaction initiator added to the base material resin is desirably 0.5% by mass or more and 3.0% by mass or less. The amount of the photoinitiator to be added can be specified, for example, by measuring the absorption wavelength of the photoinitiator by ultraviolet absorption spectrum analysis.

In the present embodiment, the curing reaction rate calculated based on infrared light absorption of the coating material 17 on the surface portion of the inter-barrel portion 8 and the coating material 17 on the bottom side of the terminal 1 on the back side of the lead wire 13 is It is desirable that the difference is within 3%.

Here, the curing reaction rate of the coating material 17 can be measured as follows by measuring the infrared light absorption peak at a wave number of 1407 cm ⁻¹ with the peak appearing at a wavelength of 1506 to 1570 cm ⁻¹ as a reference peak. can.

For the prepared coating material, the acryl double bond reaction rate of the ultraviolet curable resin is measured by microscopic ATR (Attenuated Total Reflection) measurement by the FT-IR method, and the curing reaction rate is evaluated. ATR measurement is a quantitative measurement in the depth direction of the sample, in which a crystal with a higher refractive index than the sample is brought into contact with the sample, infrared light is incident on the sample, and the spectrum absorbed by the sample and reflected by the crystal is measured. measurement. By using crystals with different refractive indices, it is possible to change the amount of penetration in the depth direction of the sample. The sinking amount can be calculated using Snell's law shown in the following equation.

Here, dp is the depth of penetration, λ is the wavelength of infrared light, _n1 is the refractive index of the crystal, _n2 is the refractive index of the sample, and θ is the incident angle of the infrared light. As is clear from Equation 1, the relationship between the wave number of infrared light and the depth of penetration determined by ATR measurement depends on the crystal used. Typical ATR crystal refractive indices are KRS-5: 2.40, ZnSe: 2.41, Ge: 4.01, Diamond: 2.37, Si: 3.41. When ATR measurement is performed using a diamond crystal, for example, at a wave number of 1407 cm ⁻¹ , the depth of penetration is 1.4 μm. At a wave number of 810 cm ⁻¹ , the depth of penetration is 2.4 μm.

After curing, the coating material is taken out from each of the surface and the deep part and evaluated by microscopic ATR measurement by the FT-IR method. From the evaluation results by the FT-IR method, it is possible to obtain the infrared light absorption peak and the reference peak for each coating material on the surface and deep. Then, from these surface and deep absorption peaks and reference peaks, the reaction rate difference between the surface and deep can be obtained using Equation 2.

Curing reaction rate difference (%)
= (1-(S _{Abs./S Ref.} )/(D _{Abs./D Ref.} ))×100 Equation 2
is the absorption peak of the coating material on the surface, S _Ref. is the reference peak of the coating material on the surface, D _{Abs. is} the absorption peak of the coating material in the deep part, and D _Ref. is the reference peak.

If the difference in the curing reaction rate calculated based on infrared light absorption is within 3%, there is almost no difference in the curing reaction rate of the coating material between the surface and the deep part, so the thermal shock resistance performance can be enhanced.

Next, a method for manufacturing the electric wire with terminal 10 will be described. First, as shown in FIG. 3, the terminal 1 and the covered conductor 11 in which the tip of the covering portion 15 is peeled off to expose the conductor 13 are prepared.

Next, the conductor wire 13 of the coated conductor wire 11 is arranged in the conductor crimping portion 7 and the covering portion 15 is arranged in the covering crimping portion 9 . At this time, the tip portion of the covering portion 15 is positioned in the inter-barrel portion 8 . Next, the conductor wire 13 is crimped by the conductor crimping part 7, the covering part 15 is crimped by the covering crimping part 9, and the covered conductor 11 and the terminal 1 are connected by crimping.

Next, the coating material 17 is applied with, for example, a dispenser to at least the portion where the conductor 13 is exposed from the inter-barrel portion 8 to the conductor crimping portion 7, and is cured. The electric wire 10 with a terminal can be obtained by the above.

It is desirable that the coating material 17 has a viscosity of 300 to 3000 mPa·s during application. If the viscosity of the coating material 17 is too high, it becomes difficult to permeate the conductive wire 13 and allow the coating material 17 to permeate the lower portion of the conductive wire 13 . On the other hand, if the viscosity of the coating material 17 is too low, the applied coating material 17 will flow, making it difficult to ensure the desired thickness.

As described above, according to the present embodiment, since the aminoketone-based first photoreaction initiator is included as the photoreaction initiator, even if the resin is colored with a coloring agent or the like, it can be efficiently cured. In addition, since it contains a second photoreaction initiator that has photobleaching properties with respect to light in the ultraviolet region, when light is irradiated and curing starts, the absorbance of the resin decreases due to photobleaching, and the light penetrates deeper. can be reached. Thus, in the present embodiment, the aminoketone-based first photoinitiator and the photobleachable second photoinitiator are used in combination, for example, when colored for visibility. Even so, the deep part of the coating material 17 can be cured efficiently. Note that the coating material 17 of the present embodiment is effective not only when coloring is performed by adding a coloring agent, but also when the resin itself is colored, and when there is a possibility of discoloration of the resin. Also, it is naturally effective when it is colorless and transparent during manufacturing and storage, such as when it is colored at the time of application.

Moreover, by mixing a thioxanthone-based sensitizer, the absorption wavelength of the aminoketone-based photoreaction initiator can be shifted to the longer wavelength side, for example, the absorption in the vicinity of 405 nm can be enhanced. Therefore, since the coating material 17 can be cured using a light source with a longer wavelength, the light can reach a deeper portion.

In this embodiment, the member to be coated is the electric wire 10 with terminal to which the coated conductor 11 and the terminal 1 are connected, and the coating material 17 is applied to the electric wire 10 with terminal, which is the member to be coated, and cured. Although an example has been described, the present invention is not limited to this. The coating material 17 can be used in other fields as long as it is a member to be coated that needs to be coated with a resin coating for corrosion prevention and protection and penetrated into a deeper portion of the coating material 17 . For example, any process for applying resin to a member to be coated, such as a coating process for optical fibers, a resin coating process for electronic parts and optical pickups, a print resist curing process, and a resin coating process for bonding various members, can be used. Also available in the field.

Next, an electric wire with a terminal was experimentally produced using a plurality of coating materials, and each sample was tested, which will be described below.

As described above, the coated conductor was crimped at the crimped portion of the terminal, and the coating material was applied to the exposed portion of the conductor and cured. At this time, various electric wires with terminals were obtained by changing the type and viscosity of the coating material to be applied. Each condition and result are shown in Table 1.

The resin formulation in the table shows the type of photoreaction initiator mixed with the base material resin, and as the aminoketone photoreaction initiator, IRGACURE 379 (trade name, manufactured by BASF) was used, and the thioxanthone-based sensitizer was used. As the Kayacure DETX-S (trade name, manufactured by Nippon Kayaku Co., Ltd.), as the acylphosphine oxide photoreaction initiator, IRGACURE 379 (A in the table) and Lucirin-TPO9 (B in the table) (both (trade name, manufactured by BASF) was used, and IRGACURE OXE01 (trade name, manufactured by BASF) was used as the oxime ester photoreaction initiator. In addition, other photoinitiators include a hydroxyketone photoinitiator (IRGACURE 184 (trade name, manufactured by BASF)) and an alkyphenone photoinitiator (IRGACURE 1173 (trade name, manufactured by BASF)). was used. Note that the droxyketone-based photoreaction initiator and the alkyphenone-based photoreaction initiator do not have photobleaching properties in the ultraviolet region. In addition, 2% by mass of Pigment Red 122 (quinacridone) was added as a coloring agent to some of the resins for coloring.

In addition, the wire with terminal whose coating material is cured by each wavelength is dismantled, and the surface and deep coating materials in the part between barrels (the surface part in the part between barrels and the coating material on the bottom side of the terminal on the back side of the conductor) ) were sampled and subjected to microscopic ATR measurement by the FT-IR method. 660/610IR manufactured by VARIAN (currently Agilen Technologies) was used as a device for microscopic ATR measurement in the FT-IR method. As a detector, a silver-cadmium-tellurium compound (MCT) detector was used. As measurement conditions, the scanning speed was set to 25 kHz, the incident angle to 45 degrees, the resolution to 4 cm ⁻¹ , and the aperture size to 100 μm×100 μm.

From the evaluation results by the FT-IR method, the absorption peak and reference peak of infrared light at the surface and the deep part are obtained, and using the above-mentioned formula 2, the hardening degree difference (hardening reaction rate difference) at the surface and deep part asked for When the difference in curing degree was 3% or less, it was rated as ◯, when it exceeded 3% and 10% or less, it was rated as Δ, and when it exceeded 10%, it was rated as x.

In addition, each wire with terminals was subjected to a thermal shock test with 1000 cycles of 120°C x 30 minutes to -40°C x 30 minutes, and the positive pressure sealability of the wire with terminals after the thermal shock test was evaluated. bottom. The samples subjected to the thermal shock test were those cured by irradiation with light of 385 nm.

FIG. 4 shows an outline of the positive pressure test method. One end of the terminal-equipped wire 10 was placed in a water tank 21 filled with water, and pressurized air was sent from the end of the coated wire 11 toward the terminal 1 by the regulator 22 . Incidentally, the air pressure was set to 49 kPa. The sealing performance under positive pressure was evaluated by blowing air from the covered conductor of the electric wire with a terminal toward the terminal, and evaluating whether air leaked from the terminal 1 or not.

In the "positive pressure test after thermal shock test" in the table, ◯ indicates that there was no leakage in the positive pressure test after the thermal shock test described above, and x indicates that there was even partial leakage.

In addition, the “visibility” of each terminal-equipped wire was checked after curing of the coating material. The case where it was easy to understand that the conductor was completely covered with the coating material was rated as ◯, and the case where the presence or absence of the coating material was difficult to understand was rated as x.

As a comprehensive evaluation, 〇 in both the positive pressure test after the thermal test and the visibility item is evaluated as 〇, and either the visibility or the positive pressure test after the thermal test is evaluated as ×. bottom.

From the results, Examples 1 to 3 containing a photoinitiator with photobleaching properties, an aminoketone photoinitiator, and a thioxanthone-based sensitizer are colored, but the positive pressure test after the cold and heat test is 〇 Since it is colored, the visibility is also 0, and the overall evaluation is 0. This is due to the effect of the photoinitiator having photobleaching properties and the effect of shifting the absorption wavelength of the aminoketone-based photoinitiator, which is not easily affected even if colored, to the longer wavelength side. This is because the irradiation of the light on the wavelength side enabled hardening to a deep portion.

On the other hand, in Comparative Examples 1 to 4, in which only photoreaction initiators having photobleaching properties are used, in the case of being colored (Comparative Examples 1, 3, and 4), the positive pressure test after the thermal test was x. , and when not colored (Comparative Example 2), the visibility was x. This is because when the resin is not colored, the photobleaching effect sufficiently advances hardening to the deep part, but if the resin is colored, it is more susceptible to that effect than the aminoketone-based photoreaction initiator. , it is thought that the hardening in the deep part was slightly weakened.

In addition, in Comparative Examples 5 to 7, in which only the aminoketone-based photoreaction initiator was used, the positive pressure test after the cold/heat test was x regardless of the presence or absence of coloration. This is because deep-part curability is low with only an aminoketone-based photoreaction initiator, as compared with a photoreaction initiator having photobleaching properties. Although the details are omitted, the addition of the thioxanthone-based sensitizer reduced the difference in the degree of cure and improved the deep-part curability.

In addition, in Comparative Examples 8 and 9, which are only photoinitiators that do not have photobleaching properties without using aminoketone-based photoinitiators, the difference in the degree of cure between the surface and the deep part is 10 at any wavelength. %, and hardening did not progress to the deep part.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not influenced by the above-described embodiments. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. be understood to belong to

Reference Signs List 1 Terminal 3 Terminal main body 4 Transition portion 5 Crimping portion 7 Lead wire crimping portion 8 Inter-barrel portion 9 Insulated crimping portion 10 Wire with terminal 11 . Intermediate portion 109 …… Covered crimping portion 111 …… Covered lead wire 115 …… Coated portion 117 …… Resin member

Claims (6)

A resin film structure in which a coating material is applied to a member to be coated and cured, wherein the member to be coated is a terminal-equipped wire in which a coated conductor and a terminal are connected,
The coated conductor includes a coated portion and a conductive wire exposed from the tip of the coated portion,
The terminal has a terminal body and a crimping portion, and the crimping portion includes a conductor crimping portion to which the conductor wire is crimped, a covering crimping portion to which the covering portion is crimped, the conductor crimping portion and the covering crimping portion. and a portion between the barrels, and at least a portion where the conductor wire is exposed from the barrel portion to the conductor crimping portion is covered with the covering material,
In the coating material, a photoreaction initiator is added to a base material resin,
The photoreaction initiator includes a first aminoketone-based photoreaction initiator that generates radicals when irradiated with light in the ultraviolet region, and a second photoreaction initiator that has photobleaching properties with respect to light in the ultraviolet region. including
The first photoreaction initiator generates radicals by irradiation with light in a wavelength range of 365 nm to 405 nm,
The electric wire with a terminal, wherein the second photoreaction initiator contains at least one of an acylphosphine oxide photoreaction initiator and an oxime ester photoreaction initiator. For the coating material, the coloring pigment or dye is selected from cyanine compounds, phthalocyanine compounds, naphthoquinone compounds, diimmonium compounds, naphthalocyanine compounds, squalium dyes, quinone compounds, azo compounds, quinacridones, dioxane, benzimidazolones, and carbon black. 2. The electric wire with a terminal according to claim 1, which contains one kind or a combination of two or more kinds. The aminoketone-based first photoinitiators include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholino linophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone The electric wire with a terminal according to claim 1 or 2. The acylphosphine oxide photoinitiator is selected from bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide,
The oxime ester photoinitiator includes 1.2-octanedione, 1-[4-(phenylthio)-, 2-(0-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2 -methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime). The base resin of the coating material is a modified acrylate and further contains one or two selected from moisture-curable silicon-modified acrylate and thermosetting epoxy-modified acrylate. The electric wire with a terminal according to any one of claims 1 to 4. The difference in the curing reaction rate calculated based on infrared light absorption between the coating material on the surface portion in the inter-barrel portion and the coating material on the bottom surface side of the terminal on the back side of the conductor is within 3%. The electric wire with a terminal according to any one of claims 1 to 5.

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