JP2014147192A - Water cut-off method and water cut-off structure of wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut off water simply and reliably at the connection of a wire and a terminal, or at the wire terminal concentrated connection.SOLUTION: Whole circumference of a core wire 1a-1 exposed by stripping the insulation coating 1b of a wire 1 is covered with a dark curable ultraviolet curing resin 5, including the strip end 1c. Thereafter, it is irradiated with ultraviolet light 7 thus curing the entirety including the ultraviolet curing resin 5 located on the dark side.

Description

  The present invention relates to a water stopping method and a water stopping structure for an electric wire, and more specifically, to stop water at a terminal connecting portion and an electric wire terminal concentrated connecting portion of an electric wire terminal.

Conventionally, it is necessary to make the electric wire wired in the inundation generation region of the automobile have a water stop structure.
When connecting the ground terminal to the ground wire terminal and fixing the ground terminal to the vehicle body panel, the connection between the wire terminal and the ground terminal is made of an ultraviolet-curing type to prevent water from entering the ground wire terminal. The water is stopped using a sealant. For example, in WO2007 / 013589 (Patent Document 1), as shown in FIGS. 8A and 8B, when the ground terminal 100 is crimped and connected to the end of the electric wire 1, the insulation coating 1b of the electric wire 1 is applied. The core wire 1a is exposed between the crimped core wire barrel 100b and the core wire 1a exposed by peeling the crimped insulation coating barrel 100a and the insulation coating 1b, and an ultraviolet curable sealant 110 is applied to the exposed core wire. It is applied. In order to infiltrate the sealing agent 110 from the peeled end 1c into the insulating coating 1b, an electric wire terminal connected to a ground terminal is set on an inclined setting jig 130, and ultraviolet rays are irradiated from above.

  Moreover, when connecting many electric wires collectively, the core wire exposed from many electric wire terminals is welded, and the terminal concentration connection part is provided. As a water stop structure of this terminal concentration welded part, as shown in FIG. 9, in Japanese Patent Laid-Open No. 2003-9334 (Patent Document 2), the terminal concentration connection part 200 is inserted into a resin cap 201 and the tape 203 is inserted. The cap 201 is filled with a sealant 202 made of silicone rubber and cured at room temperature.

WO2007 / 013589 JP 2003-9334 A

  In the water stop structure of the crimping connection portion between the ground terminal and the electric wire of Patent Document 1, a sealing agent is applied to the exposed portion of the core wire, and is inclined so that the sealing agent flows into the electric wire from the peeled end of the insulation coating. The sealant is cured by UV irradiation. However, since the sealing agent that has penetrated into the electric wire is not irradiated with ultraviolet rays, it is naturally cured and cannot be cured in a short time. Therefore, the fluid sealing agent flows down in the electric wire, and the sealing agent is not filled and cured in the electric wire on the peeled end side, so that voids are easily generated. Also, the sealing agent applied to the core wire exposed between the barrels of the ground terminal is not cured by ultraviolet irradiation, and the natural curing is awaited because the lower surface side contacting the setting jig 130 is a dark side where ultraviolet irradiation is not performed. In other words, the sealing agent flows down on the inclined setting jig 130 before curing, and is not sealed with the sealing agent. Thus, both the water stop on the ground terminal connection side and the water stop from the wire terminal to the wire have a problem of low reliability.

  In addition, in the water stop structure in which the electric wire terminal concentrated connection portion 200 of Patent Document 2 is inserted into the cap and the sealing agent is filled in the cap, three members such as the cap 201, the sealing agent 202, and the tape 203 are required. . Moreover, the cap 201 of several sizes according to the magnitude | size of the electric wire terminal concentration connection part 200 is needed, and a number of parts increases. Further, when the cap 201 is filled with the sealant 202, the opening of the cap 201 needs to be raised upward, and the sealant filling operation on the wire harness assembly work table cannot be easily performed. For this reason, there is a problem that the number of work steps increases when performed in a separate step.

  The present invention has been made in view of the above problems, and the insulation coating of the electric wire is peeled off to expose the core wire, and the waterproofing of the exposed core wire and the waterproofing from the peeled end of the insulation coating to the electric wire are easily performed. It is an object of the present invention to provide a method for water-stopping an electric wire that can be reliably achieved and a water-stop structure formed by the method.

  In order to solve the above-mentioned problem, the present invention covers the entire circumference of the core wire exposed by peeling the insulation coating of the electric wire, including the peeled end, and then irradiating with ultraviolet rays. And the water stop method of the electric wire characterized by hardening the whole including the ultraviolet curable resin located in the dark part side is provided.

The ultraviolet curable resin is covered as a gel-like sheet covering the entire circumference of the core wire without any gaps.
The sheet is thinned to facilitate winding around the outer periphery of the core wire, preferably 1 mm or less in thickness, and the lower limit is preferably about 0.1 mm.
In this way, if the gel-like sheet is covered only by being wound around the core wire, the equipment becomes unnecessary as compared with the case where the core wire is filled with silicone rubber or ultraviolet curable resin made of molten resin, and on the wire harness assembly work table. Can be done easily.
In addition, you may apply | coat the said ultraviolet curable resin made into the comparatively high viscosity with low fluidity to a core wire instead of a gel-like sheet | seat.

  The gel-like sheet is wound around a core wire on a workbench for assembling a wire harness, and then an ultraviolet irradiation lamp mounted at a fixed position on the worktable is used to irradiate ultraviolet rays from one side to the sheet of the electric wire at a fixed position. It is preferable to irradiate and perform a water stop operation on the work table.

  Specifically, the terminal is connected to the exposed core wire by peeling off the insulation coating at the wire end, and then the insulation coating is peeled from the wire connection side of the terminal excluding the portion electrically connected to the counterpart terminal. Covering the periphery of the end with the UV curable resin.

Similar to Patent Document 1, the present invention is particularly preferably used when an earth terminal fixed to a vehicle body panel in a flooded area is connected to an electric wire terminal.
Even in Patent Document 1, a sealant that is cured by ultraviolet irradiation is used, and a sealant that has penetrated into an electric wire is naturally cured. However, in the present invention, a UV-curable resin that is dark-curing is used. The ultraviolet curable resin that permeates into the side opposite to the side and the electric wire can be rapidly cured as described later by ultraviolet irradiation from one side. Therefore, it is possible to quickly cure the ultraviolet curable resin in the dark part which is exposed to the lower surface side of the core wire exposed to the outside between the barrels of the terminal and the dark part which is not irradiated with ultraviolet rays because it penetrates into the electric wire. It can be surely prevented from being washed away, and water stop reliability can be improved.

  Also, the insulation coating is peeled off at a plurality of wire terminals, the core wires are bundled and ultrasonic welding or resistance welding is performed to provide a terminal concentrated connection part, and then the entire terminal concentrated connection part and the skinned end of the insulation coating are provided. Is covered with the ultraviolet curable resin.

  Although it is the same as that of Patent Document 2 in that the terminal concentration connection portion is stopped, since only the dark portion curable ultraviolet curable resin is required in the present invention, the material cost can be reduced. Further, in Patent Document 2, water stopping work cannot be performed on the wire harness assembly work table, but in the present invention, it can be performed on the wire harness assembly table as described above, and the work process can be simplified.

  Further, the core wire exposed by another electric wire is bundled with the core wire exposed by peeling off the intermediate portion in the length direction of the electric wire and caulked with an intermediate crimp terminal, and then the intermediate crimp terminal, the core wire and the insulation Covering the periphery of the peeled end of the coating with the UV curable resin.

The dark part curable ultraviolet curable resin is:
With respect to a polyisocyanate compound having two or more isocyanate groups, the number of hydroxyl groups was set to 1 or less by forming two or more hydroxyl groups of a polyol having two or more hydroxyl groups to form an ester bond with (meth) acrylate. An ultraviolet curable material (A) mainly composed of a (meth) acrylate of a polyol;
A chain transfer agent (B) comprising a metal complex compound containing at least one compound selected from a urethane bond, a urea bond and an isocyanate group, and a metal-containing compound; and an ultraviolet polymerization initiator (C). When,
It consists of the composition which mix | blended.
The ultraviolet curable resin has heat resistance that does not melt at 120 ° C. or lower.

As the ultraviolet curable resin having dark part curability blended with the chain transfer agent (B), an ultraviolet curable composition described in WO2012 / 102299 related to the prior application of the present applicant is suitably used.
The dark part curable ultraviolet curable composition is made of an ultraviolet curable resin that is located in a dark part where irradiation light does not reach and can cure a part where no radical is generated, and the ultraviolet curable material (A) and the chain transfer agent (B). And an ultraviolet polymerization initiator (C).
In addition, the whole can be reliably cured even when an ultraviolet / light transmission inhibitor composed of organic / inorganic fillers, carbon / metal particles, fibers, polymers / oligomers, various modifying additives and the like is blended.

The UV curable resin having dark portion curable properties does not require heat treatment or moisture curing treatment, and when a portion of the UV curable resin is irradiated with UV rays and cured, the dark portions where the UV rays are blocked are also sequentially transferred by the chain transfer agent. It can be cured, and the entire part impregnated with the ultraviolet curable resin can be rapidly cured including the dark part.
Therefore, the ultraviolet curable resin having the dark portion curability covered with the core wire can sequentially cure the portion located on the dark portion side opposite to the irradiation side only by irradiating ultraviolet rays from the outside. Specifically, for example, when the UV curable resin blended with a chain transfer agent is irradiated with UV light for 10 seconds with a UV lamp, the portion irradiated with the lamp is instantly cured and the light of the UV lamp reaches. Even dark areas can be cured by leaving for several tens of seconds.

In addition, when it is set as the said gel-like sheet | seat, an adhesive may be apply | coated to the whole surface of this sheet | seat, and after winding around a core wire, an adhesive may be apply | coated to an overlapping part.
As described above, when the adhesive is applied in the wound state, the adhesive can be fixed simply by being brought into close contact with the outer peripheral surface of the core wire, and means for holding the sheet in the wound state at the time of ultraviolet irradiation in the subsequent work becomes unnecessary.

Furthermore, this invention provides the water stop structure of the electric wire formed with the said water stop method.
If the structure is provided with a water stop part formed by curing the UV curable resin, the water stop part is cured, so there is no need to protect it with a rigid material such as a resin cap or resin case. Can be made lighter and lighter.
When the wire harness including the electric wire having the water stop structure is sheathed with an exterior material such as a corrugated tube, since the water stop portion is not enlarged, the terminal concentrated connection portion and the intermediate connection portion are disposed in the corrugated tube. Can be accommodated.

  As described above, in the present invention, since the dark portion curable ultraviolet curable resin is used to prevent the core wire exposed by peeling off the insulation coating of the electric wire, the core wire is covered with the ultraviolet curable resin. After that, the whole can be quickly cured simply by irradiating ultraviolet rays from one side. Therefore, the water stop reliability can be improved and the water stop work can be easily performed.

  In particular, since it is only necessary to wrap a sheet made of an ultraviolet curable resin around the water-stop portion of the electric wire terminal and then irradiate the ultraviolet ray, it can be continuously performed on the assembly work table of the wire harness.

(A)-(F) is drawing which shows the water stop method of 1st Embodiment of this invention. (A) (B) is drawing which shows the modification of 1st Embodiment. It is drawing which shows 2nd Embodiment of this invention. It is drawing which shows the modification of 2nd Embodiment. It is drawing which shows 3rd Embodiment of this invention. It is drawing which shows 4th Embodiment of this invention. It is drawing which shows 5th Embodiment of this invention. (A) (B) is drawing which shows a prior art example. It is drawing which shows another prior art example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A to 1F show a first embodiment.
1st Embodiment has stopped the connection part of the ground terminal of an electric wire terminal.
The electric wire 1 is a round electric wire having a circular cross section in which a core wire 1a in which a number of strands are twisted is covered with an insulating coating 1b made of an insulating resin, and the insulating coating 1b at the end of the electric wire 1 is peeled off from the peeled end 1c. Until the core wire 1a is exposed.

  The ground terminal 2 is crimped and connected to the exposed core wire 1a. The ground terminal 2 is provided with a core wire barrel 2b and an insulation coating barrel 2c in succession to an electrical contact portion 2a provided with a bolt hole 2h. It is crimped and connected to the electric wire 1.

  In the connection portion of the ground terminal 2, the peeled end 1c and the core wire 1a-1 are exposed between the core wire barrel 2b of the ground terminal 2 and the insulation coating barrel 2c. In order to prevent the exposed core wire 1a-1 from being submerged and to prevent the submerged end 1c from infiltrating into the insulating coating 1b, the steps shown in FIGS. Water-stopping treatment is performed, and as shown in (F), the water-stopping treatment is performed by covering with a tubular water-stopping material 10 made of a cured ultraviolet curable resin.

The water stop processing method of the electric wire terminal connected with the said earthing terminal is demonstrated.
As shown in FIG. 1B, the entire circumference of the core wire barrel 2b, the exposed core wire 1a-1, and the insulation coating barrel 2c is covered on the terminal side of the electric wire 1 crimped to the ground terminal 2 shown in FIG. Thus, the gel-like sheet | seat 5 which consists of dark part curable ultraviolet curable resin is wound. The sheet 5 may be wound once. In order to maintain the winding state, as shown in FIG. 1 (C), an adhesive may be applied in advance to the entire back surface of the sheet 5, or after the winding, the adhesive is applied to the overlapping surface and adhered. Also good.

  The sheet 5 has a thickness of about 1 mm and is easy to wind. Therefore, as shown in FIG. 1 (D), the sheet 5 is easily wound around the connection portion between the electric wire terminal and the ground terminal 2 and wound. The sheet can be adhered to the outer peripheral surfaces of the electric wire 1 and the ground terminal 2 without a gap.

  Next, as shown in FIG. 1 (E), the ultraviolet ray irradiation lamp 7 irradiates the portion around which the sheet 5 is wound from above. Neither the electric wire 1 connected to the ground terminal 2 nor the ultraviolet irradiation lamp 7 need be rotated during the irradiation. When a part of the sheet 5 is irradiated with ultraviolet rays, the irradiated portion is instantly cured, and as will be described later, the curing is chained and rapidly cured to a portion where the ultraviolet rays are not irradiated (that is, a dark portion).

The entire sheet 5 covering the outer peripheral surface of the core wire barrel 2b of the ground terminal 2 from the vicinity of the peeled end 1c of the electric wire 1 is cured, and as shown in FIG. Thus, the outer periphery of the connection portion between the electric wire 1 and the ground terminal 2 is in close contact with and covered.
Thus, since the core wire 1a-1 exposed between the peeled end 1c and the barrel of the ground terminal 2 is covered with the water-stopping material 10 without any gap, it is possible to reliably prevent the occurrence of flooding.

The dark part curable ultraviolet curable resin to be the gel-like sheet 5 will be described in detail.
The ultraviolet curable resin contains an ultraviolet curable material (A), a chain transfer agent (B), and an ultraviolet polymerization initiator (C).

The chain transfer agent (B), which is a component of the UV curable resin having dark part curability, includes (a) a compound containing at least one selected from a urethane bond, a urea bond, and an isocyanate group, and (b) And a metal complex compound containing a metal-containing compound.
The chain transfer agent (B) can exhibit intermolecular or intramolecular transmission functions after stabilizing the generated radicals. Therefore, the chain transfer agent (B) can instantaneously transmit the radicals generated in the system to a place where no radicals are generated, and the polymerization reaction can be started to advance the radical polymerization reaction. As a result, when the chain transfer agent (B) is blended with the ultraviolet curable material (A), the inside and the back side (that is, the dark part) where the irradiation light that has conventionally been difficult to cure cannot be surely cured. Can do. In addition, there is no need for an operation step of mixing a curing agent immediately before curing, a step of curing a dark part by heating or moisture curing after irradiation, etc., and the curing operation can be performed in a short time, and the curing workability is excellent. Yes.

In the chain transfer agent (B), the urethane bond, urea bond, and isocyanate group-containing compound of the component (a) are represented by the following (Formula 1) urethane bond part, the following (Formula 2) urea bond part, What is necessary is just to contain at least 1 sort (s) selected from the isocyanate group shown by the following (Formula 3) in 1 molecule or more.
(Formula 1) -NH-COO-
(Formula 2) -NH-CO-NH-
(Formula 3) -N = C = 0

The metal-containing compound (b) constituting the chain transfer agent (B) preferably contains at least one metal selected from tin, copper, zinc, cobalt and nickel. Among these, it is activated at a relatively high temperature (for example, a temperature of about 120 ° C.), and at room temperature, the effect of improving the curing rate in the dark part is hardly exhibited, so that the storage stability of the composition can be increased. From the viewpoint, a zinc-based metal complex compound or a copper-based metal complex compound is more preferable.
Specific examples of the metal-containing compound (b) include metal-containing compounds listed in paragraphs 0010 and 0154 of WO 2012/102299 relating to the prior application of the present applicant.

  In the chain transfer agent (B), the blending ratio of the above (a) and (b) is (a) :( b) = 100: 0.001 to 100: 10, preferably 100: 0.005 in mass ratio. Preferably it is 100: 5.

In the metal complex compound functioning as the chain transfer agent (B) composed of (a) and (b), the tin-based metal complex compound may be bis (2,4-pentanedionato) tin, dibutyltin bis ( Trifluoromethanesulfonate), dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, phthalocyanine tin (IV) dichloride, tetrabutylammonium difluorotriphenyltin, phthalocyanine tin (II), tributyl (2-pyridyl) tin, tributyl ( 2-thienyl) tin, tributyltin acetate, tributyl (trimethylsilylethynyl) tin, trimethyl (2-pyridyl) tin and the like.
Examples of copper-based metal complex compounds include bis (hexafluoroacetylacetonato) copper (II), bis (2,4-pentanedionato) copper (II), and bis (1,3-propanediamine) copper (II). Dichloride, bis (8-quinolinolato) copper (II), bis (trifluoro-2,4-pentanedionato) copper (II), bis (2-hydroxyethyl) dithiocarbamate copper (II), diethyldithiocarbamate copper, Dimethyldithiocarbamate copper (II), ethylenediaminetetraacetate copper (II) disodium, phthalocyanine copper (II), dichloro (1,10-phenanthroline) copper (II), phthalocyanine copper, tetra-4-tert-butylphthalocyanine copper, Tetrakis (acetonitrile) copper (I) hexafluorophosphate, copper naphthenate, etc. It can gel.
Zinc-based metal complex compounds include bis [2- (2-benzothiazolyl) phenolato] zinc (II), bis [2- (2-benzoxazolyl) phenolato] zinc (II), bis (2-hydroxyethyl) ) Zinc (II) dithiocarbamate, bis (2,4-pentanedionato) zinc (II), bis (8-quinolinolato) zinc (II), bis (tetrabutylammonium) bis (1,3-dithiol-2- Thione-4,5-dithiolato) zinc complex, disodium ethylenediaminetetraacetate, zinc diphenyldithiocarbamate (II), zinc dibutyldithiocarbamate (II), zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc phthalocyanine, naphthenic acid Zinc and the like can be mentioned.
Examples of cobalt-based metal complex compounds include bis (cyclopentadienyl) cobalt (III) hexafluorophosphate, [1,1′-bis (diphenylphosphino) ferrocene] cobalt (II) dichloride, and bis (hexafluoroacetyl). Acetonato) cobalt (II), (1R, 2R) -N, N′-bis [3-oxo-2- (2,4,6-trimethylbenzoyl) butylidene] -1,2-diphenylethylenediaminatocobalt ( II), (1S, 2S) -N, N′-bis [3-oxo-2- (2,4,6-trimethylbenzoyl) butylidene] -1,2-diphenylethylenediaminatocobalt (II), bis ( 2,4-pentanedionato) cobalt (II), bis (trifluoro-2,4-pentandionato) cobalt (II), lid Cyanine cobalt (II), ethylenediaminetetraacetic acid disodium cobalt, hexaammine cobalt (III) chloride, N, N′-disalicylic ethylenediamine cobalt (II), [5,10,15,20-tetrakis (4-methoxy) Phenyl) porphyrinato] cobalt (II), tris (2,4-pentanedionato) cobalt (III), cobalt naphthenate, and the like.
Nickel-based metal complex compounds include [1,2-bis (diphenylphosphino) ethane] nickel (II) dichloride, bis (dithiobenzyl) nickel (II), bis (hexafluoroacetylacetonato) nickel (II) Bis (2,4-pentanedionato) nickel (II), bis (tetrabutylammonium) bis (maleonitriledithiolato) nickel (II) complex, bis (tricyclohexylphosphine) nickel (II) dichloride, bis (tri Phenylphosphine) nickel (II) dichloride, bromo [(2,6-pyridindiyl) bis (3-methyl-1-imidazolyl-2-ylidene)] nickel bromide, disodium nickel (II) ethylenediaminetetraacetate, dibutyldithiocarbamic acid nickel II), such as diethyldithiocarbamate nickel may be mentioned.
The following are mentioned as a commercial item of the said metal complex compound.
BPDZ: [“Bis (2,4-pentanedionato) zinc (II)” manufactured by Tokyo Chemical Industry Co., Ltd.]
-CDEDTC: [Copper (II) diethyldithiocarbamate manufactured by Tokyo Chemical Industry Co., Ltd.]
DBTDL: [“Dibutyltin dilaurate” manufactured by Tokyo Chemical Industry Co., Ltd.]

  The ultraviolet curable material (A) has a hydroxyl group in which two or more hydroxyl groups of a polyol having two or more hydroxyl groups form an ester bond with (meth) acrylate with respect to a polyisocyanate compound having two or more isocyanate groups. It is preferable that the main component is a (meth) acrylate of a polyol whose number is set to 1 or less.

Since the number of hydroxyl groups in the (meth) acrylate of the polyol is set to 1 or less, the urethanization reaction with the polyisocyanate compound is suppressed from proceeding in a state where it is blended with the polyisocyanate compound. Thereby, the storage stability of this composition is improved. The number of hydroxyl groups in the (meth) acrylate of the polyol may be 1 or 0. From the viewpoint of storage stability of the present composition, it is more preferably 0.
Examples of the (meth) acrylate of the polyol include dipropylene glycol diacrylate, tetraethylene glycol diacrylate, 1-acryloyloxy-3-methacryloyloxy-2-propanol (2-hydroxy-3-acryloyloxypropyl methacrylate), and the like. preferable. Specific examples of the (meth) acrylate include those described in paragraph 0131 of the aforementioned WO2012 / 102299.
The following are mentioned as a commercial item of this (meth) acrylate.
・ DPGA: [Dipropylene glycol diacrylate manufactured by Tokyo Chemical Industry Co., Ltd.]
・ TEGDA: [“Tetraethylene glycol diacrylate” manufactured by Tokyo Chemical Industry Co., Ltd.]
AMPOH: [“1-acryloyloxy-3-methacryloyloxy-2-propanol (2-hydroxy-3-acryloyloxypropyl methacrylate)” manufactured by Tokyo Chemical Industry Co., Ltd.]
-IBA: [“Isobornyl acrylate” manufactured by Tokyo Chemical Industry Co., Ltd.]

Specific examples of the polyisocyanate compound having two or more isocyanate groups include aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, and aromatic polyisocyanates. Also, biuret type polyisocyanates obtained by reacting these polyisocyanates with water, adduct type polyisocyanates obtained by reacting these polyisocyanates with polyhydric alcohols such as trimethylolpropane, and some of these polyisocyanates. Examples thereof include liquid prepolymers polymerized with polyesters and polyether derivatives, and multimers obtained by converting these polyisocyanates to isocyanurates. These may be used alone or in combination of two or more.
The following are mentioned as a commercial item of the said polyisocyanate compound.
・ N3600: ["Death Module N3600" manufactured by Sumika Bayer Urethane Co., Ltd.]
・ N3200: ["Death Module N3200" manufactured by Sumika Bayer Urethane Co., Ltd.]
Moreover, the following UP-1 and UP-2 are mentioned as a synthetic | combination product of a urethane prepolymer.

The urethane prepolymer UP-1 is synthesized by the following method.
A reaction vessel equipped with a stirrer was charged with 80 parts by mass of polypropylene glycol having a number average molecular weight of 400, 40 parts by mass of hexamethylene diisocyanate and 0.1 parts by mass of dibutyltin dilaurate, and the liquid temperature was changed from room temperature to 50 ° C. while stirring. Raise over time. Thereafter, a small amount is sampled, and FT-IR is measured, and stirring is continued at 50 ° C. while confirming absorption of isocyanate near 2300 cm −1. The reaction ends when the absorption disappears. This is designated as urethane prepolymer UP-1.
The urethane prepolymer UP-2 is synthesized by the following method.
A reaction vessel equipped with a stirrer was charged with 50 parts by mass of a terminal diol-type polycaprolactone having a number average molecular weight of 1250, 13.5 parts by mass of hexamethylene diisocyanate and 0.1 parts by mass of dibutyltin dilaurate, and the liquid temperature was adjusted to room temperature while stirring. To 50 ° C over 1 hour. Thereafter, a small amount is sampled, and FT-IR is measured, and stirring is continued at 50 ° C. while confirming absorption of isocyanate near 2300 cm −1. The reaction ends when the absorption disappears. This is designated as urethane prepolymer UP-2.

  In the ultraviolet curable material (A), the blending ratio of the polyisocyanate compound and the (meth) acrylate of the polyol is 90:10 to 10:90, preferably 80:20 to 20:80, in terms of mass ratio. When the blending amount of the (meth) acrylate of the polyol exceeds 90 by mass ratio, the amount of the polyisocyanate compound responsible for the curing reaction in the dark part becomes insufficient because the blending amount of the polyisocyanate compound is too large. The curing rate tends to be slow. On the other hand, even if the blending amount of the (meth) acrylate of the polyol is less than 10 by mass ratio, the generation amount of active species for curing the polyisocyanate compound is insufficient, and the curing rate in the dark part tends to be slow.

  The blending ratio of the ultraviolet curable material (A) and the chain transfer agent (B) is preferably a mass ratio of (A) :( B) = 90: 10 to 10:90. Specifically, the (meth) acrylate of the ultraviolet curable material (A) is 50 to 70 mass%, preferably 55 to 65 mass%, and the chain transfer agent (B) is 50 to 30 mass%, preferably 45 to 45 mass%. 35% by mass.

The ultraviolet polymerization initiator (C) is used for the purpose of causing radical reaction of (meth) acrylate of polyol. The ultraviolet polymerization initiator (C) is not particularly limited as long as it is a compound that absorbs ultraviolet rays and initiates a radical reaction. Examples of the ultraviolet polymerization initiator (C) include those described in paragraph 0133 of WO2012 / 102299, such as 1-hydroxycyclohexyl phenyl ketone and 2-tail anthraquinone.
Commercially available products of the ultraviolet polymerization initiator (C) include, for example, IRGACURE 184, 369, 651, 500, 907, CGI 1700, CGI 1750, CGI 1850, CG24-61; (Manufactured by UCB).

  As a compounding quantity of the said ultraviolet-ray polymerization initiator (C), it is preferable to exist in the range of 0.01-10 mass parts with respect to 100 mass parts of said ultraviolet curing materials (A). More preferably, it is the range of 0.1-7 mass parts. When the blending amount of the ultraviolet polymerization initiator is less than 0.01 parts by mass, the amount of the ultraviolet polymerization initiator is too small and the curing reaction by ultraviolet rays is difficult to start. On the other hand, when the blending amount of the ultraviolet polymerization initiator exceeds 10 parts by mass, an insoluble material is generated, and the physical properties of the cured product may be impaired.

  In addition to the above-mentioned various components, various compounding agents can be blended with the ultraviolet curable resin, if necessary, within a range not impairing the object of the present invention. As a compounding agent, the stabilizer, plasticizer, softener, pigment, dye, antistatic agent, flame retardant, adhesiveness imparting agent, sensitizer, dispersion described in paragraphs 0117 to 0126 of the above-mentioned WO2012 / 102299 Agents, solvents, antibacterial and antifungal agents. Each compounding agent can be used in combination as appropriate. Moreover, the compounding quantity of a compounding agent can be suitably determined according to a use etc.

  The method for producing the ultraviolet curable resin is not particularly limited, but each of the above components is sufficiently kneaded by using a stirring device such as a mixing mixer under a reduced pressure or an inert gas atmosphere such as nitrogen and uniformly dispersed. The method of making it preferable is.

The sheet 5 made of the dark-curing ultraviolet curable resin used as a water-stop sheet in the present invention is in a gel form before ultraviolet curing, and the sheet 5 has flexibility and flexibility as a whole. Therefore, the sheet 5 before being irradiated with ultraviolet light can be brought into close contact with the outer peripheral surface of the electric wire 1 and the ground terminal at the connection portion between the ground terminal 2 and the electric wire 1 and can be easily wound by sushi or bonded winding.
In addition, the ultraviolet ray hits upon UV irradiation and curing starts, and the inside of the UV ray blocked from the part where the curing starts and the lower side opposite to the irradiation side are also cured by the chain transfer agent (B). Although the time is slightly delayed, it hardens in tens of seconds.

2A and 2B show a first modification of the first embodiment.
In the first modification, a ground terminal 2B capable of crimping the two electric wires 1-1 and 1-2 is used.
The crimp portion of the ground terminal 2B and the electric wires 1-1 and 1-2 is covered with a single large sheet 5 as shown. The sheet 5 is cured by irradiating ultraviolet rays as in the embodiment, and the ground terminal connection portions of the two wires are simultaneously cured.

FIG. 3 shows a second embodiment.
In the second embodiment, the female terminal 15 and the male terminal 16 that are connected to the electric wire terminal and are connected to each other are connected to the connecting portion between these terminals and the electric wire 1 as shown by cross diagonal lines in FIG. After winding the sheet 5 made of a dark-curing ultraviolet curable resin, the sheet 5 is cured by being irradiated with ultraviolet rays and water-stopped.

FIG. 4 shows a modification of the second embodiment.
In the modified example, after the female terminal 15 and the male terminal 16 are fitted and electrically connected, the sheet 5 is wound around the fitted electrical connection portion 17 again, as shown by cross diagonal lines in the figure, It is cured by irradiating with ultraviolet rays. In this way, when the fitting portion between the terminals and the connection portion between the terminal and the electric wire are all covered with a water-stopping cylinder made of a cured ultraviolet curable resin, the entire terminal connection portion can be water-stopped, It can also be accommodated in a corrugated tube.

FIG. 5 shows a third embodiment.
In the third embodiment, a dark part curable ultraviolet curable resin 18 having a low fluidity and a relatively high viscosity is discharged from a discharge pipe 19 and applied without using a sheet made of a dark part curable ultraviolet curable resin. . Thereafter, the ultraviolet curable resin 18 applied by irradiating ultraviolet rays is cured.
As described above, the dark-curing ultraviolet curable resin may be directly applied without forming a sheet, but the gel-like sheet 5 has an advantage of easy handling.

FIG. 6 shows a fourth embodiment of the present invention.
In the fourth embodiment, the terminal concentrated connection portion 20 is provided by stripping the insulation coating 1b at the ends of the plurality of electric wires 1 and bundling the core wires 1a and performing ultrasonic welding or resistance welding.
From the front end of the core wire 1a including the terminal concentrated connection portion 20 to the insulating coating 1b at the periphery of the peeled end 1c, the sheet 5 made of a dark portion curable ultraviolet curable resin is wound, as in the first embodiment. It is cured by irradiating with ultraviolet rays.
Thereby, the whole terminal concentration connection part 20 and the core wire exposure part will be in the state closely_contact | adhered and covered with the water stop material 10 which hardened and became a cylinder shape, and can improve water stop performance.
In addition, the number of parts can be reduced, for example, the resin cap described in Patent Document 2 of the prior art can be eliminated, and the tape winding operation can be eliminated, thereby simplifying the process.

FIG. 7 shows a fifth embodiment of the present invention.
In the fifth embodiment, the core wire 1a exposed by the other electric wire 1W is bundled to the core wire 1a exposed by peeling off the intermediate portion in the length direction of the electric wire 1, and is caulked and connected by the intermediate crimping terminal 30. The sheet 5 used in the first embodiment is wound around the intermediate crimp terminal 30, the core wire 1a, and the peripheral edge of the peeled end 1c of the insulating coating 1b as shown by cross hatching in the figure. Thereafter, the sheet 5 is cured by irradiating with ultraviolet rays, and the intermediate connection portion is cured and tightly covered with a tubular water-stopping material.

DESCRIPTION OF SYMBOLS 1 Electric wire 1a Core wire 1b Insulation coating 1c Skinned end 2 Ground terminal 2b Core wire barrel 2c Insulation coating barrel 5 Gel-like sheet 10 Cylindrical water stop material which hardened ultraviolet curing resin

Claims (8)

  Cover the entire circumference of the core wire exposed by peeling the insulation coating of the wire, including the stripped end, with a dark part curable ultraviolet curable resin, and then irradiate ultraviolet rays to irradiate the ultraviolet curable resin located on the dark part side. A method for water-stopping an electric wire, characterized by curing the entire structure. The ultraviolet curable resin is
With respect to a polyisocyanate compound having two or more isocyanate groups, the number of hydroxyl groups was set to 1 or less by forming two or more hydroxyl groups of a polyol having two or more hydroxyl groups to form an ester bond with (meth) acrylate. An ultraviolet curable material (A) mainly composed of a (meth) acrylate of a polyol;
A chain transfer agent (B) comprising a metal complex compound containing at least one compound selected from a urethane bond, a urea bond and an isocyanate group, and a metal-containing compound; and an ultraviolet polymerization initiator (C).
The method for water-stopping an electric wire according to claim 1, which is an ultraviolet curable resin having a dark portion curability.   The method for water-stopping an electric wire according to claim 1 or 2, wherein the ultraviolet curable resin is covered with a gel-like sheet covering the entire circumference of the core wire without a gap.   The gel-like sheet is wound around a core wire on a workbench for assembling a wire harness, and then an ultraviolet irradiation lamp mounted at a fixed position on the worktable is used to irradiate ultraviolet rays from one side to the sheet of the electric wire at a fixed position. The method for water-stopping an electric wire according to any one of claims 1 to 3, wherein the water-stopping operation is performed on the work table.   Connect the terminal to the exposed core wire by peeling off the insulation coating at the wire terminal, then, from the wire connection side of the terminal excluding the portion electrically connected to the counterpart terminal, to the periphery of the skinned end of the insulation coating, The method for water-stopping an electric wire according to any one of claims 1 to 4, wherein the wire is covered with the ultraviolet curable resin.   A plurality of the wire ends are stripped of the insulation coating, the core wires are bundled, and ultrasonic welding or resistance welding is performed to provide a terminal concentrated connection portion, and then the entire terminal concentrated connection portion and the stripped end of the insulation coating are provided. The method for water-stopping an electric wire according to any one of claims 1 to 4, wherein the ultraviolet curable resin covers the periphery.   The core wire exposed by another electric wire is bundled with the core wire exposed by peeling off the intermediate portion in the length direction of the electric wire, and caulked with an intermediate crimp terminal, and then the intermediate crimp terminal, the core wire, and the insulation coating The method for water-stopping an electric wire according to any one of claims 1 to 4, wherein the ultraviolet curable resin covers the periphery of the peeled end of the wire.   The water stop structure of the electric wire formed with the water stop method of any one of Claim 1 thru | or 7.

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