JP2016058317A - Wire Harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire harness which prevents peeling of a covering material and a waterproof agent in a splice waterproof portion of the wire harness even after exposed to a high temperature environment, and can satisfy adequate waterproof performance.SOLUTION: A wire harness has: a conductor exposure portion formed of a bundle of a conductor in which a plurality of insulated electric wires including a splice portion are exposed; and a waterproof portion where the outer peripheral surface on ends of each covering material of each of the insulated electric wires adjacent to the conductor exposure portion is successively covered with a waterproof agent and the conductor exposure portion is sealed. The waterproof portion is coated and sealed by a waterproof agent formed of a resin cured product. A ratio [E/A] between a Young's modulus E (MPa) at room temperature after high-temperature durability of the waterproof agent and a tensile bond strength A (MPa) of the waterproof agent after high-temperature durability to an electric wire coating material is set at 3.0 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wire harness, and particularly to a wire harness suitable for in-vehicle use.

  The in-vehicle wire harness is exposed to a high temperature environment during use. Moreover, waterproof performance is required in the splice portion of the wire harness. As a method for waterproofing a splice portion of a wire harness exposed to such a high temperature environment, it is known to use a moisture curable resin or an ultraviolet curable resin as a waterproofing agent (see, for example, Patent Documents 1 and 2).

  Patent Document 1 is a method of covering a splice part with a cover, injecting a liquid silicone resin between the cover and the wire conductor, causing a crosslinking reaction at room temperature, and curing to a silicone gel.

  In Patent Document 2, a waterproofing agent made of an ultraviolet curable resin is filled in a splice part and is cured in a state of being covered with a light-transmitting protective sheet, and the waterproofing agent has a plastic of the same type as a plasticizer of an electric wire covering material. The agent is added.

Japanese Patent Laid-Open No. 4-229961 JP 2013-251166 A

  Since the method described in Patent Document 1 cures the silicone gel by moisture, it takes time to cure and the processability is poor. In addition, the plasticizer contained in the wire covering material is transferred to the waterproofing agent under a high temperature environment, and the adhesive strength of the waterproofing agent is reduced and peeled off from the wire covering material, resulting in a problem that the waterproof performance cannot be satisfied.

  The method described in Patent Document 2 suppresses the plasticizer migration of the wire coating material in a high-temperature environment by adding a plasticizer of the same type as the plasticizer contained in the wire coating material to the waterproof UV curable resin. doing. However, if the wire harness is left in a high-temperature environment for a long time, the plasticizer contained in the resin and the wire coating material volatilizes, leading to thinning of the wire coating material, and between the waterproof resin and the wire coating material. There was a problem that the waterproof performance could not be satisfied due to peeling.

  The present invention has been made to solve the above problems, and the object of the present invention is to peel off the covering material and the waterproofing agent in the splice waterproofing portion of the wire harness even after being exposed to a high temperature environment. It is providing the wire harness which can prevent that and can obtain favorable waterproof performance.

The wire harness of the present invention is
The covering material of each insulated wire of the plurality of insulated wires is partially removed, and in the conductor exposed portion where the conductor is exposed, the conductors of the plurality of insulated wires are connected to each other to form a splice portion, A conductor exposed portion composed of a bundle of exposed conductors of a plurality of insulated wires including a splice portion and an outer peripheral surface of each covering material end of each insulated wire adjacent to the conductor exposed portion are continuously connected by a waterproofing agent. A wire harness having a waterproof part that is covered and sealed with the exposed conductor part,
The waterproof part is covered and sealed with a waterproofing agent made of a cured resin,
The ratio [E / A] of the Young's modulus E (MPa) at room temperature after high-temperature durability of the waterproofing agent and the tensile adhesive strength A (MPa) at room temperature of the waterproofing agent to the wire coating material after high-temperature durability, 3.0 or less,
This is the gist.

  In the wire harness of the present invention, it is preferable that the waterproofing agent is a cured product of an ultraviolet curable resin composition.

  The wire harness of the present invention is a ratio between the Young's modulus E (MPa) at room temperature after high-temperature durability of the waterproofing agent and the tensile adhesive strength A (MPa) at room temperature of the waterproofing agent after high-temperature durability to the wire coating material. By adopting a configuration where [E / A] is 3.0 or less, it is possible to prevent the coating material and the waterproofing agent from peeling off at the splice waterproof part of the wire harness even after being exposed to a high temperature environment. Thus, good waterproof performance can be obtained.

  The above-described configuration of the present invention provides good waterproof performance due to the following actions. In the wire harness, the electric wire becomes thin and thin due to a decrease in the plasticizer in a high temperature environment. If it does so, a peeling stress will be applied to the waterproofing agent filled between the electric wires in the perpendicular direction, and distortion will be added. Here, when waterproofing agents (ultraviolet curable resins) having different Young's moduli are given the same strain, the waterproofing agent having a higher Young's modulus increases the stress applied to the resin. From this, the magnitude of the value of the tensile adhesive strength in the vertical direction and the Young's modulus after high-temperature durability affects whether or not the waterproofing agent and the covering material are peeled off. Therefore, when the ratio [E / A] of Young's modulus E / tensile bond strength A is 3.0 or less, the water-proof property is waterproof. It was found that no peeling occurred between the agent and the covering material, and good waterproof performance was obtained.

FIG. 1 is a perspective view showing an external appearance in the vicinity of a water stop middle splice part of an example of the wire harness of the present invention. FIG. 2 is a horizontal sectional view taken along line AA of FIG. 3A to 3C show an example of the manufacturing process of the wire harness of the present invention, and are explanatory diagrams in the vicinity of the water stop middle splice. 4 (a) to 4 (e) show manufacturing steps of another example of the method for manufacturing the wire harness of the present invention, and are explanatory diagrams in the vicinity of the water stop intermediate splice portion. FIG. 5 is a graph showing the relationship between the post-endurance Young's modulus E and the post-endurance tensile adhesive strength A of Examples and Comparative Examples.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a perspective view showing an external appearance of an example of a wire harness according to the present invention in the vicinity of an intermediate splice portion, and FIG. 2 is a horizontal sectional view taken along line AA of FIG. The wire harness 1 of the aspect shown in FIG.1 and FIG.2 is comprised from the wire bundle in which the four insulated wires 4 coat | covered with the coating | covering material 3 which consists of an insulator around the conductor 2 which consists of core wires are bundled. Yes.

  In the intermediate splice portion 20 of the wire harness 1, the plurality of insulated wires 4 of the wire bundle has a conductor exposed portion 5 in which the covering material 3 is peeled and removed to expose the bundle of conductors 2 inside. In the conductor exposed portion 5, the conductors 2, 2, 2, 2 of the plurality of insulated wires 4, 4, 4, 4 are joined to each other and the insulated wires 4 are electrically connected.

  In the wire harness 1, the periphery of the intermediate splice part 20 is covered with a protective sheet 30 and a waterproofing agent 40 to constitute the waterproof part 10. In the waterproof part 10, the conductor exposed part 5 and the outer peripheral surface of the covering part 6 at the end of each covering material 3 of each insulated wire 4 adjacent to the conductor exposed part 5 are continuously covered with the waterproofing agent 40. The conductor exposed portion 5 is sealed.

  The prevention unit 10 is covered and sealed with a waterproofing agent 40 made of a cured resin. The waterproofing agent 40 has a Young's modulus E (MPa) at room temperature after high-temperature durability (hereinafter sometimes simply referred to as Young's modulus E after high-temperature durability) and a room temperature of the waterproofing agent after high-temperature durability with respect to the wire coating material. The ratio [E / A] of the tensile adhesive strength A (MPa) (hereinafter sometimes simply referred to as tensile adhesive strength A after high-temperature durability) is 3.0 or lower.

  In the present invention, as a characteristic of the above waterproofing agent, a configuration in which the ratio [E / A] of Young's modulus E at room temperature after high temperature durability and tensile adhesive strength A after high temperature durability is 3.0 or less is important. . It can be considered that good waterproof performance can be obtained by the above-described configuration by the following action. In general, when a wire harness is used in a high-temperature environment, the plasticizer in the coating material of the electric wire volatilizes, and the electric wire becomes thin due to a decrease in the plasticizer. If it does so, peeling stress will be applied to the waterproofing agent with which it filled between the electric wires in the perpendicular direction (radial direction of an electric wire), and distortion will be added. Here, consider how the stress applied to the resin differs for waterproofing agents having different Young's moduli (for example, ultraviolet curable resins). When the same strain is applied to waterproofing agents having different Young's moduli, the waterproofing agent having a higher Young's modulus increases the stress applied to the resin. For this reason, the magnitude of the tensile adhesive strength A in the vertical direction after high temperature durability and the value of the Young's modulus after high temperature durability affects whether or not the waterproofing agent and the covering material are peeled off. Therefore, when a study was conducted by paying attention to the relationship between Young's modulus E / tensile bond strength A, the ratio [E / A] of Young's modulus E after high temperature durability / tensile adhesive strength A after high temperature durability was 3. When it was 0 or less, it was found that peeling did not occur between the waterproofing agent and the covering material, and satisfactory waterproof performance was satisfied.

  The Young's modulus E (MPa) is a value measured in accordance with JIS K 7161 using a No. 3 dumbbell as a test piece, a tensile speed of 1 mm / min, and room temperature (23 ° C.). The Young's modulus after endurance is to evaluate the Young's modulus by measuring the sample at room temperature after heat-treating the sample at 120 ° C. for 200 hours.

  The tensile bond strength A is a value measured at room temperature according to JIS K 6849. As the adherend, a PVC plate containing the same amount of plasticizer as the insulated wire was used. The size of the PVC plate was 40 mm long × 20 mm wide × 1 mm thick. The sample was prepared by making the small face of two PVC plates face each other with a gap of 1 mm, filling a waterproofing agent between the two PVC plates, and curing. A sample for a tensile test was obtained in which two PVC plates were bonded via a waterproofing agent formed to have a width of 20 mm, a thickness of 1 mm, and a length of 1 mm. This sample was heat-treated at 120 ° C. for 200 hours and then subjected to a tensile test at room temperature to obtain a tensile adhesive strength after durability.

  The waterproofing agent 40 is not particularly limited as long as it is a cured product of a waterproof curable resin. It is particularly preferable to use a cured product of an ultraviolet curable resin composition. An existing ultraviolet curable material can be used as the ultraviolet curable resin composition. Specifically, a cured product is obtained by irradiating ultraviolet rays with a mixture of a polymerizable compound, which is a curable component such as a (meth) acrylate oligomer or (meth) acrylate monomer, and a photopolymerization initiator. Anything can be used.

  In the present invention, the description of “(meth) acrylate” means acrylate and methacrylate. The curing principle of the ultraviolet curable resin composition is that the photopolymerization initiator absorbs ultraviolet rays (ultraviolet light) to generate active species such as radical species, and the active species is carbon-carbon such as (meth) acrylate. These double bonds are radically polymerized and cured.

  In order to set the ratio [E / A] of the Young's modulus E (MPa) after the high temperature durability of the waterproofing agent and the tensile adhesive strength A (MPa) after the high temperature durability to 3.0 or less, various components of the composition What is necessary is just to adjust a kind and a compounding quantity suitably.

  The ultraviolet curable resin composition contains a polymerizable compound, a photopolymerization initiator, a thermal radical polymerization initiator, and the like. Examples of the polymerizable compound include those obtained by combining a urethane acrylate oligomer and an acrylate monomer.

For example, the ultraviolet curable resin composition used for a waterproofing agent can be comprised from the composition of the following component. Hereinafter, each component will be described.
(A) Urethane (meth) acrylate oligomer,
(B) (meth) acrylate monomer,
(C) a vinyl lactam compound,
(D) Photopolymerization initiator

(A) Urethane (meth) acrylate oligomer In the composition, it is used as a base as a waterproofing agent from the viewpoint of easy adjustment of waterproofness, flexibility, adhesiveness, viscosity and the like. The urethane (meth) acrylate oligomer is a compound having a (meth) acryloyl group obtained by reacting an isocyanate compound and a polyol compound (hydroxyl group-containing compound) with a hydroxy (meth) acrylate.

  Examples of the urethane (meth) acrylate oligomer are obtained by reacting urethane acrylate, polytetramethylene glycol, diisocyanate and hydroxyalkyl acrylate obtained by reacting bisphenol A / ethylene oxide addition diol, diisocyanate and hydroxyalkyl acrylate. Examples thereof include urethane acrylate obtained by reacting urethane acrylate, diisocyanate and hydroxyalkyl acrylate. These oligomers may be used alone or in combination of two or more.

  As said diisocyanate, the following compound is mentioned, for example. Methylene diisocyanate, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate (LDI), 1,3,6-hexamethylene triisocyanate, etc. Aliphatic isocyanate. Hydrogenated-4,4′-diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated-xylylene diisocyanate (hydrogenated XDI), 1,4-cyclohexane diisocyanate, hydrogenated-2,4-tolylene diisocyanate (hydrogenated TDI) , Cycloaliphatic isocyanates such as isophorone diisocyanate (IPDI) and norbornene diisocyanate (NBDI). Aromatic aliphatic isocyanates such as xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI); 1,4-diphenyl diisocyanate, 2,4 or 2,6-tolylene diisocyanate (TDI), 2,4 or 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), 3,3 ′ -Polyisocyanates such as aromatic isocyanates such as dimethyl-4,4'-diphenylmethane diisocyanate, O-tolidine diisocyanate, polyphenylmethane polyisocyanate (crude MDI), triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate. These may be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing compound include alcohols having 1 to 30 carbon chains having a hydroxyl group at the terminal, (poly) ethylene glycol as a terminal diol, (poly) propylene glycol as a terminal diol, (poly) hexamethylene glycol as a terminal diol, and terminal Examples include (poly) caprolactone of diol, (poly) ester (poly) ol of terminal diol, (poly) amide of terminal diol, (poly) ester of terminal diol, and the like.

  A metal-containing compound may be added to the urethane acrylate. Addition of the metal-containing compound improves dark part curability. As the metal-containing compound, those containing at least one metal selected from tin, copper, zinc, cobalt, and nickel are preferably used. As the metal-containing compound, conventionally known compounds can be used without any particular limitation as long as a plurality of kinds of the metals are contained in the constituent molecules in the form of a metal salt or a metal complex.

  As said metal salt, forms, such as carboxylate of the said metal seed | species, phosphate, sulfonate, hydrochloride, bromate, (per) (sub) chlorite, are mentioned.

  The metal complex is not particularly limited as long as it is coordinated and stabilized with an organic ligand capable of forming a coordination bond with the metal species and 1: 1 to 1: 4 (metal: ligand). A well-known thing can be used without this.

  Specific examples of the metal-containing compound include bis (2,4-pentanedionato) tin, dibutyltin bis (trifluoromethanesulfonate), dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and 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, bis (hexafluoroacetylacetonato) copper (II), bis (2,4-pentandionato) copper (II), bis (1,3-propanediamine) copper (II) dichloride, bis (8-quinolinolato ) Copper (II), bis (trifluoro-2,4-pentandionato) copper (II), bis (2-hydroxyethyl) dithiocarbamic acid (II), copper diethyldithiocarbamate, copper (II) dimethyldithiocarbamate, disodium ethylenediaminetetraacetate (II), phthalocyanine copper (II), dichloro (1,10-phenanthroline) copper (II), phthalocyanine copper, tetra -4-tert-butyl phthalocyanine copper, tetrakis (acetonitrile) copper (I) hexafluorophosphate, copper naphthenate, bis [2- (2-benzothiazolyl) phenolato] zinc (II), bis [2- (2-benzo Oxazolyl) phenolato] zinc (II), zinc (II) bis (2-hydroxyethyl) dithiocarbamate, bis (2,4-pentanedionato) zinc (II), bis (8-quinolinolato) zinc (II) Bis (tetrabutylammonium) bis (1,3-dithiole-2-thione-4,5-dithiolato) zinc complex, disodium zinc ethylenediaminetetraacetate, zinc dibenzyldithiocarbamate (II), dibutyldithio Zinc (II) carbamate, zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc phthalocyanine, zinc naphthenate, bis (cyclopentadienyl) cobalt (III) hexafluorophosphate, [1,1'-bis (diphenylphosphate) Fino) ferrocene] cobalt (II) dichloride, bis (hexafluoroacetylacetonato) cobalt (II), (1R, 2R) -N, N'-bis [3-oxo-2- (2,4,6-trimethyl) Benzoyl) 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), phthalocyaninecobalt (II) ), Ethylenediaminetetraacetic acid disodium cobalt, hex Ammine cobalt (III) chloride, N, N'-disalicylic ethylenediamine cobalt (II), [5,10,15,20-tetrakis (4-methoxyphenyl) porphyrinato] cobalt (II), tris (2,4 -Pentandionato) cobalt (III), cobalt naphthenate, [1,2-bis (diphenylphosphino) ethane] nickel (II) dichloride, bis (dithiobenzyl) nickel (II), bis (hexafluoroacetylacetonate ) Nickel (II), bis (2,4-pentanedionato) nickel (II), bis (tetrabutylammonium) bis (maleonitriledithiolato) nickel (II) complex, bis (tricyclohexylphosphine) nickel (II) Dichloride, bis (triphenylphosphine) nickel (II) dichloride, bromo [(2,6-pyridinediyl) bis (3-methyl-1-imidazolyl-2-ylidene)] nickel bromide, ethylenediaminetetraacetic acid Examples thereof include disodium nickel (II) acid, nickel dibutyldithiocarbamate (II), nickel diethyldithiocarbamate and the like. These may be used alone or in combination of two or more.

(B) (Meth) acrylate monomer By selecting the type and the number of functional groups, the initial Young's modulus in the composition can be adjusted, and the overall viscosity can be adjusted. The (meth) acrylate monomer is not particularly limited as long as it is a compound having one or more (meth) acrylate groups in the molecule ((meth) acrylate), and conventionally known ones can be used.

  Examples of the acrylate monomer include a chain acrylate monomer and a cyclic acrylate monomer. The cyclic acrylate monomer is an acrylate monomer having a cyclic structure such as an alicyclic ring or an aromatic ring. Specific examples of the (meth) acrylate monomer include isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, Cyclohexyl (meth) acrylate, (meth) acrylic acid, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, (meth) acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate 4-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, octyl (meth) acrylate Rate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Isostearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol ( (Meth) acrylate, methoxypolypropylene glycol (meth) acrylate, polyoxyethylene nonylphenyl ether Relate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7 -Mono (meth) acrylates such as amino-3,7-dimethyloctyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, butanediol di (meth) Acrylate, hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, decanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 2-hydroxy Cy-3-acryloyloxypropyl methacrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tricyclode Candimethylol di (meth) acrylate, 1,4-butanepolyol di (meth) acrylate, 1,6-hexanepolyol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene Glycol di (meth) acrylate, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, polyester di (meth) acrylate, tris (2-hydroxyethyl) Sosocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, EO adduct of bisphenol A di (meth) acrylate, hydrogenated bisphenol A EO adduct or PO adduct polyol di (meth) acrylate, epoxy (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether of bisphenol A, triethylene glycol divinyl ether, trimethylolpropane tri ( (Meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane EO adduct tri (meth) acrylate, trisacryloyloxyethyl phosphate, pentaerythritol tet (Meth) acrylate, tetrafurfuryl alcohol oligo (meth) acrylate, ethyl carbitol oligo (meth) acrylate, 1,4-butanediol oligo (meth) acrylate, 1,6-hexanediol oligo (meth) acrylate, trimethylol Examples thereof include poly (meth) acrylates such as propane oligo (meth) acrylate, pentaerythritol oligo (meth) acrylate, (poly) urethane (meth) acrylate, and (poly) butadiene (meth) acrylate. These may be used alone or in combination of two or more.

(C) Vinyl lactam compound When a composition hardens | cures, it can provide softening property and can improve adhesiveness. It is also possible to adjust the Young's modulus after durability. Specific examples of the vinyl lactam compound include N-vinyl pyrrolidone and N-vinyl caprolactam. Examples of compounds that can impart softening properties include hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, and the like.

(D) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is a compound that absorbs ultraviolet rays and initiates radical polymerization, and conventionally known ones can be used.

  Specific examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, ethyl anthraquinone, triphenylamine, carbazole, 3 -Methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2- Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthiol Xanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the photopolymerization initiator, commercially available products such as IRGACURE184, 369, 651, 500, 907, CGI1700, CGI1750, CGI1850, CG24-61; ) Etc. can be used.

  A thermal radical polymerization initiator may be added to the composition in place of the radical polymerization initiator, and the composition may be configured as a thermosetting resin. Examples of the thermal radical polymerization initiator include azoisobutyl nitrile (AIBN), benzoyl peroxide (BPO), lauroyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert -Peracid compounds such as butyl perbenzoate and cyclohexanone peroxide.

  In addition to the above components, the ultraviolet curable resin composition includes a stabilizer, a plasticizer, a softener, a pigment, a dye, an antistatic agent, a flame retardant, an adhesiveness imparting agent, a sensitizer, a dispersant, and a solvent. An antibacterial and antifungal agent may be added.

  Examples of the stabilizer include an anti-aging agent, an antioxidant, and a dehydrating agent. Specifically, these include, for example, hindered phenol compounds, hindered amine compounds (anti-aging agents), butylhydroxytoluene, butylhydroxyanisole, triphenyl phosphate, etc. (antioxidants), maleic anhydride, phthalic anhydride, Examples thereof include acid chlorides (dehydrating agents) such as benzophenone tetracarboxylic dianhydride, quicklime, carbodiimide derivatives, and stearyl chloride. A small amount of a polymerization inhibitor such as metaquinone can also be used as a stabilizer.

  Examples of the plasticizer include dioctyl adipate, dibutyl sebacate, diethylhexyl sebacate, isodecyl succinate, diethylene glycol dipenzoate, pentaerythritol ester, butyl oleate, methyl acetylricinoleate, tricresyl phosphate, phosphoric acid Examples include trioctyl, propylene glycol adipate polyester, butylene glycol adipate polyester, phenol, lauric acid, stearic acid, docosanoic acid, paraffinic oil, naphthenic oil, and aroma oil.

  Examples of the pigment include inorganic pigments such as titanium dioxide, zinc oxide, ultramarine, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate, and organic pigments such as azo pigments and copper phthalocyanine pigments. Can be mentioned.

  Examples of the antistatic agent include hydrophilic compounds such as quaternary ammonium salts, polyglycols, and ethylene oxide derivatives.

  Examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, and brominated polyether.

  Examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and epoxy resins.

  Examples of the sensitizer include dimethylformamide, N-methylpyrrolidone, triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, As isoamyl 4-dimethylaminobenzoate and commercially available products, Ubekryl P102, 103, 104, 105 (above, manufactured by UCB) and the like can be mentioned.

  Examples of the dispersant include surfactants such as polyoxyethylene nonylphenyl ether and polyethylene glycol octylphenyl ether.

  The solvent is not particularly limited as long as it can dissolve the solid component in the composition of the curable material. Specifically, the solvent may be a polar solvent such as tetrahydrofuran, dimethylformamide, ethyl acetate, methyl ethyl ketone, or dichloroethane. And chlorinated solvents such as trichlorobenzene.

  The waterproofing agent is formed by irradiating the ultraviolet curable resin composition with ultraviolet rays and curing. Irradiation light may be visible light in addition to ultraviolet rays. Various conventionally known irradiation devices can be used as the ultraviolet irradiation device. Moreover, the irradiation conditions of ultraviolet rays can be appropriately set according to each ultraviolet curable material.

  The wire harness shown in FIG.1 and FIG.2 has the softness | flexibility which the protection sheet 30 can deform | transform following the deformation | transformation of the surface of the waterproofing agent 40. FIG. The protective sheet 30 covers the periphery of the waterproofing agent 40 in a state of being in close contact with the surface of the waterproofing agent 40. The waterproofing agent 40 is cured by being irradiated with ultraviolet rays while being penetrated into the conductor exposed portion 5 of the insulated wire.

  Moreover, the waterproofing agent 40 of the waterproof part 10 is hardened in a state of being in close contact with the surface of the covering material 3 of the insulated wire 4 adjacent to the conductor exposed part 5. In the waterproof part 10, the waterproofing agent 40 covers the periphery of the covering part 6 before and after the conductor adjacent to the conductor exposed part of the insulated wire 4. Thus, the waterproofing agent 40 covers the covering portion 6, thereby preventing moisture from entering from the gap between the covering material 3 and the conductor 2.

  As the covering material 3 of the insulated wire 4, a soft vinyl chloride resin composed of a vinyl chloride resin and a plasticizer is used. Examples of the plasticizer include phthalate ester plasticizers such as diisononyl phthalate (DINP), trimellitic acid ester plasticizers such as tri-2-ethylhexyl trimellate, 2-ethylhexyl adipate, dibutyl sebacate, and the like. Aliphatic dibasic acid ester plasticizers, epoxy plasticizers such as epoxidized soybean oil, and phosphate ester plasticizers such as tricresyl phosphate.

  For the conductor 2 of the insulated wire 4, a single wire or a stranded wire of a wire such as copper, a copper alloy, or aluminum is used.

  The intermediate splice part 20 is obtained by partially removing the covering material 3 at the intermediate part in the longitudinal direction of the insulated wire 4 to expose the conductor 2 and joining the conductor 2 of another insulated wire 4 to the conductor 2. The conductor 2 of the other insulated wire 4 may be exposed at the intermediate portion in the longitudinal direction of the insulated wire 4 or may be exposed at the end of the insulated wire 4. . Here, the latter example will be described. Moreover, in the wire harness 1, the insulated wire 4 is not limited to four, What is necessary is just two or more, and the number of the insulated wires 4 is not specifically limited.

  In the intermediate splice portion 20, the conductors 2 can be joined to each other by means such as welding by resistance welding, ultrasonic welding, laser welding, or the like. The conductor 2 in the splice part 20 may be joined by a method in which a component such as an intermediate crimp terminal is crimped to the joint part.

  The protective sheet 30 covers the surface of the waterproof agent 40 in a state of being in close contact with the surface of the waterproof agent 40. The protective sheet 30 has transparency to irradiation light such as ultraviolet rays when the curable resin composition of the waterproofing agent 40 is cured. The light transmittance of the protective sheet 30 is preferably, for example, an ultraviolet transmittance of 50% or more, and more preferably an ultraviolet transmittance of 90% or more. The thickness of the protective sheet 30 is preferably 100 μm or less, more preferably 5 to 50 μm.

  As the protective sheet 30, a wrap sheet of olefin resin such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and polyvinylidene fluoride, or a wrap sheet of general-purpose resin such as polyester, polyethylene terephthalate, and nylon can be used. . The protective sheet 30 is preferably a sheet of polyvinyl chloride resin, polyvinylidene chloride resin, or polyvinylidene fluoride resin that has particularly good self-adhesion (adhesion).

  Hereinafter, the manufacturing method of the wire harness of FIG. 1 will be described. 3A to 3C show an example of the manufacturing process of the wire harness, and are explanatory diagrams in the vicinity of the water stop intermediate splice. As shown in FIG. 3A, first, a wire bundle 7 in which an intermediate splice portion 20 is formed in advance using a plurality of insulated wires is prepared. The wire bundle 7 has a conductor exposed portion 5 where the insulator 3 of the insulated wire 4 is removed and the internal conductor 3 is exposed.

  Then, as shown in FIG. 3A, a protective sheet 30 large enough to cover the intermediate splice portion 20 is prepared, and the intermediate splice portion 20 of the wire bundle 5 is placed on the protective sheet. Next, a waterproofing agent is supplied onto the intermediate splice unit 20. The waterproofing agent 40 is discharged and supplied from the nozzle 60 of the discharge device by a predetermined amount. Supply the waterproofing agent at room temperature. In addition, after supplying the waterproofing agent 40 to the protection sheet 30, you may make it mount an electric wire bundle on a waterproofing agent.

  Next, as shown in FIG. 3B, the folded portion side of the protective sheet 30 is wound around the intermediate splice portion 20 and the waterproof agent 40, and the overlapping portion where the protective sheets 30 overlap each other in the portion without the intermediate splice portion 20. Bend it to 32. The overlapping portion 32 of the protective sheet 30 is maintained in an overlapped state by the self-adhesiveness of the protective sheet 30.

  Next, the protective sheet 30 is wound around the surface of the waterproof agent 40 of the intermediate splice unit 20 so that the waterproof sheet 40 is filled in the protective sheet 30. After the protective sheet 30 is folded in half, the overlapping portion of the protective sheet 30 is rubbed with the roll 51 and the waterproofing agent 40 of the overlapping portion 32 is pushed toward the intermediate splice portion 20. The overlapping portion 32 of the protective sheet 30 is wound around the waterproof portion 10 to be in close contact therewith.

  Next, as shown in FIG. 3C, the overlapping portion of the protective sheet 30 is wound around the intermediate splice portion 20 and the waterproofing agent 40. When the protective sheet 30 is pulled and wound in a tensioned state, the waterproof part 10 is wound around the intermediate splice part 20 and the waterproofing agent 40 while being pressed from the outside of the protective sheet 30.

  As a result, the waterproofing agent 40 locally present around the intermediate splice part 20 is extruded and travels between the outer peripheral part of the intermediate splice part 20 and the protective sheet 30, and around the outer periphery of the intermediate splice part 20. Cover the whole. The protective sheet 30 is maintained in a state of being wound around the waterproof portion 10 by self-adhesion. Moreover, the waterproof part 10 is also maintained in a state where it is pressed from the outside of the protective sheet 30.

  Next, as shown in FIG. 3 (c), using the ultraviolet irradiation device 52, ultraviolet rays are applied to the intermediate splice unit 20 in a state where the protective sheet 30 is wound around the outer periphery of the intermediate splice unit 20 and the waterproofing agent 40. 53 is irradiated and the waterproofing agent 40 is hardened.

  As the ultraviolet irradiation device, a light source such as a bulb-type UV lamp or an LED-UV lamp in which Hg, Hg / Xe, a metal halide compound or the like is enclosed can be used. Further, the ultraviolet irradiation device may use a condensing UV irradiation device that collects and irradiates light from the light source with a reflection mirror.

  4 (a) to 4 (e) show manufacturing steps of another example of the method for manufacturing the wire harness of the present invention, and are explanatory diagrams in the vicinity of the water stop intermediate splice portion. As a method of winding the protective sheet 30 around the intermediate splice part 20, as shown in FIG. 4A, a winding device using a pair of rollers 110 arranged so as to contact each other can be used. In the winding device, when the electric wires at both ends of the intermediate splice portion 20 are moved downward along the pair of side grooves, the intermediate splice portion 20 is sandwiched between the pair of rollers 110, and the pair of rollers The roller 110 is moved downward while rotating. Hereinafter, a winding method using this winding apparatus will be described.

  First, as shown in FIG. 4A, the protective sheet 30 is placed on the top plate portion, the waterproof agent 40 is supplied onto the protective sheet 30, and the intermediate splice portion 20 is placed.

  Next, as shown in FIG. 4B, the wire bundle is moved downward along the lateral groove. The intermediate splice part 20 is sandwiched between the pair of rollers 110 while being sandwiched by the protective sheet 30. The pair of roller portions 110 sandwich the intermediate splice portion 20, the waterproof agent 40 and the protective sheet 30 while being elastically deformed according to the shape of the peripheral portion of the intermediate splice portion 20. Thereby, as shown in FIG.4 (c), the protective sheet 30 is wound around the intermediate splice part 20 and the waterproofing agent 40, while force is applied from the circumference.

  Next, as shown in FIG. 4D, the rod-shaped member 120 is moved toward the intermediate splice portion 20 with the intermediate splice portion 20 sandwiched between the pair of rod-shaped members 120. As shown in FIG. 4E, the protective sheet 30 is wound around the surface of the waterproof agent 40 in a state where the waterproof agent 40 is pressed from the outside of the protective sheet 30. After winding, the waterproofing agent 40 is cured in the same manner as shown in FIG.

  The wire harness of the present invention can be suitably used as a vehicle-mounted wire harness that is exposed to a high-temperature environment during use and requires waterproof performance of the splice part.

  Examples of the present invention and comparative examples are shown below. The present invention is not limited to these examples.

Examples 1-6, Comparative Examples 1-6
UV curable resin compositions having the component compositions shown in Tables 1 and 2 were prepared and used as waterproofing agents. The initial Young's modulus, post-endurance Young's modulus E, and post-endurance tensile adhesive strength A of each waterproofing agent were measured to determine the ratio [E / A]. The results are shown in Tables 1 and 2. Furthermore, the waterproof treatment of the intermediate splice part was given using the waterproofing agent shown in Table 1 and Table 2, the wire harness of Examples 1-6 and Comparative Examples 1-6 was produced, and the waterproof performance of each wire harness was tested. Tables 1 and 2 show the test results. Details of each component of the waterproofing agent in Tables 1 and 2, the method for producing the waterproof intermediate splice part, the waterproof test method, etc. are as follows.

(1) Adjustment of waterproofing agent-Urethane (meth) acrylate (UA-1)
Synthesis by esterification reaction of NCO terminal of urethane prepolymer composed of modified tetramethylene ether glycol (PTG-L: Hodogaya Chemical Co.), which is a copolymer polyether glycol of tetrahydrofuran and 3-methyltetrahydrofuran, and isophorone diisocyanate, and hydroxypropyl acrylate Urethane acrylate was used. The synthesis method is as follows.

[Method of synthesizing urethane acrylate]
A reaction vessel equipped with a stirrer was charged with 213 g (208 mmol) of modified polytetramethylene ether glycol having a number average molecular weight of 1020, 52 g (234 mmol) of isophorone diisocyanate and 0.05 g of dibutyltin dilaurate, and the liquid temperature was changed from room temperature to 50 with stirring. Raised to 1 ° C over 1 hour. Thereafter, a small amount was sampled, FT-IR was measured, and stirring was continued at 50 ° C. while confirming the absorption of isocyanate near 2300 cm ⁻¹ . The content of residual isocyanate groups was calculated from the absorption area of FT-IR, and the reaction was terminated when it decreased to about 15% compared to before the reaction and disappeared, and a colorless transparent viscous liquid was obtained. Further, 6.8 g (52 mmol) of hydroxypropyl acrylate and 0.02 g of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] were charged, and the liquid temperature was changed from room temperature to 50 with stirring. Raised to 1 ° C over 1 hour. Thereafter, a small amount was sampled, FT-IR was measured, and stirring was continued at 50 ° C. while confirming the absorption of isocyanate near 2300 cm ⁻¹ . The content of residual isocyanate groups was estimated from the absorption area of FT-IR, and when the absorption disappeared, the reaction was terminated, and a colorless transparent viscous liquid was obtained. This is UA-1. Both ends are diacrylates of acrylate.

・ (Meth) acrylate IBA: Isobornyl acrylate DPGA: Dipropylene glycol diacrylate (Because it has a bifunctional acrylic group, initial Young's modulus is adjusted)
・ Vinyl lactam compound NVP: N-vinylpyrrolidone (adhesion factor, Young's modulus after endurance adjustment)
・ Photopolymerization initiator
Irgacure184: BASF, 1-hydroxy-cyclohexyl-phenyl-ketone

(2) Young's modulus measurement A sample was prepared under the following conditions and measured according to JIS K 7161.
-Sample: No. 3 dumbbell-Curing conditions: 200 mW / cm ² with UV lamp (manufactured by USHIO), UV irradiation for 20 seconds-Tensile speed: 1 mm / min
Initial Young's modulus: After preparing a sample, a tensile test was performed at room temperature to obtain a tensile modulus.
Young's modulus after durability: The sample was treated at 120 ° C. for 200 hours, and then subjected to a tensile test at room temperature to obtain a tensile modulus.

(3) Measurement of tensile adhesive strength for coating material A waterproofing agent was filled between the small face surfaces (width 20 mm × thickness 1 mm) of two adherends, and the waterproof material was cured under the following conditions. A sample was created. Using this sample, after heat-treating under the following conditions, the tensile adhesive strength was measured at room temperature according to JIS K 6849, and the post-endurance tensile adhesive strength was determined.
-Adhering material: A PVC plate containing 25 wt% of trimethic acid tris (2-ethylhexyl) (TOTM) as a plasticizer was used (length 40 mm × width 20 mm × thickness 1 mm).
-Length of waterproofing agent: 1mm
・ Curing conditions for waterproofing agent: UV lamp (manufactured by USHIO) 200 mW / cm ² , UV irradiation for 20 seconds ・ Tensile speed: 50 mm / min
・ Heat treatment conditions: Heat sample at 120 ° C. for 200 hours

(4) Production of waterproof intermediate splice part A PVC-coated electric wire containing 25 wt% of tris (2-ethylhexyl) trimetate (TOTM) as a plasticizer was used. An intermediate splice work having a PVC coated electric wire with an outer diameter of 4.4 mm as a main wire and two PVC coated electric wires with an outer diameter of 3.6 mm as branch wires was produced.

(5) Filling and curing waterproof agent After using transparent PVC wrap film as a protective sheet, 1.1g of the waterproof agent is applied to the center of the wrap film, and the intermediate splice part of the intermediate splice work is placed Then, the PVC wrap film is bonded and narrowed down, and the bonded PVC wrap film is further wound to form a shape covering about 16 mm length of the intermediate splice part and the coating material surface, and a UV lamp (manufactured by USHIO INC.) Is 200 mW / cm 2. The waterproofing agent was cured by irradiating with ultraviolet rays for 20 seconds.

(6) Evaluation of waterproof performance by pressure resistance test In the pressure resistance test, an air pressure of 200 kPa was applied from all the electric wires at both ends of the harness for 1 minute in a state where the entire intermediate splice was immersed in water, and the presence or absence of air leak was observed. The case where there was no air leak was set as “◯”, and the case where air leak was confirmed during the pressurization with an air pressure of 200 kPa for 1 minute was set as “x”. About the air leaked sample, the cross section of the sample was cut | disconnected and the presence or absence of peeling with a waterproofing agent and a coating | covering material was observed. Evaluation was performed after the sample was endured at 120 ° C. for 200 hours. Further, the reduction rate of the diameter of the wire covering material in contact with the waterproofing agent due to durability at 120 ° C. for 200 hours was measured.

  FIG. 5 is a graph showing the relationship between the post-endurance Young's modulus E and the post-endurance tensile adhesive strength A of Examples and Comparative Examples. The line shown in FIG. 5 indicates [E / A] = 3. The lower side of this line is a part where [E / A] is 3 or less, and the upper part of the line is a part where [E / A] is 3 or more. In the wire harnesses of Examples 1 to 6, as shown in Table 1 and FIG. 5, Young's modulus E at room temperature after high-temperature durability and tensile adhesion of the waterproofing agent after high-temperature durability to the wire coating material are attached to the intermediate splice portion. Since a waterproofing agent having a ratio [E / A] with a strength A of 3.0 or less was used, the difference between the adhesive force to the coating material and the stress (= Young's modulus) in the peeling direction was small, so even after high temperature durability No peeling between the waterproofing agent and the covering material occurred, and the waterproofing performance was excellent.

  On the other hand, as shown in Table 2 and FIG. 5, the wire harnesses of Comparative Examples 1 to 6 are bonded to the intermediate splice portion at the room temperature after the high temperature durability and the tensile adhesion of the waterproofing agent to the wire covering material. Since a waterproofing agent having a ratio [E / A] with strength A of more than 3.0 was used, the waterproof performance after durability could not be satisfied.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  For example, in the wire harness of the above aspect, the splice portion is provided in the middle of the electric wire, but the splice portion may be provided at the end of the electric wire.

DESCRIPTION OF SYMBOLS 1 Wire harness 2 Conductor 3 Coating | covering material 4 Insulated electric wire 5 Conductor exposure part 6 Front and back coating part adjacent to conductor exposure part 7 Wire bundle 10 Water stop middle splice part (waterproof part)
20 Intermediate splice part (splice part)
40 waterproofing agent

Claims (2)

The covering material of each insulated wire of the plurality of insulated wires is partially removed, and in the conductor exposed portion where the conductor is exposed, the conductors of the plurality of insulated wires are connected to each other to form a splice portion, A conductor exposed portion composed of a bundle of exposed conductors of a plurality of insulated wires including a splice portion and an outer peripheral surface of each covering material end of each insulated wire adjacent to the conductor exposed portion are continuously connected by a waterproofing agent. A wire harness having a waterproof part that is covered and sealed with the exposed conductor part,
The waterproof part is covered and sealed with a waterproofing agent made of a cured resin,
The ratio [E / A] of the Young's modulus E (MPa) at room temperature after high-temperature durability of the waterproofing agent and the tensile adhesive strength A (MPa) of the waterproofing agent to the wire coating material after high-temperature durability is 3. A wire harness characterized by being 0 or less.   The wire harness according to claim 1, wherein the waterproofing agent is a cured product of an ultraviolet curable resin composition.