JPS61220205A - Crosslinked polyethylene insulated wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a cross-linked polyethylene insulated wire, specifically a cross-linked polyethylene insulated wire having a colored coating film with excellent adhesion formed on the surface of an insulator made of cross-linked polyethylene by irradiation with ultraviolet rays. Regarding insulated wires.

Crosslinked polyethylene is generally obtained by chemically crosslinking polyethylene using an organic peroxide or physically crosslinking it by irradiating it with electron beams, and has excellent electrical, mechanical, and thermal properties. Because of this, it is widely used as an insulating coating material for electric wires, cables, etc.

[Conventional technology]

Conventionally, polyethylene, including cross-linked polyethylene,
So-called polyolefin polymers such as polypropylene are non-polar substances and their surfaces are inert, so it is extremely difficult to form a colored coating film with strong adhesion on such polyolefin polymers. ing.

In particular, cross-linked polyethylene is difficult to dissolve even in ordinary organic solvents, and it does not melt to the thermal decomposition temperature when heated, so it is almost impossible to form a colored coating film with good adhesion on the surface using conventional solvent-based paints. has been done.

Therefore, when producing color identification wires for cross-linked polyethylene insulated wires, it is important to knead colored pigments together with the polyethylene during extrusion coating of the polyethylene before cross-linking, color the entire polyethylene resin, and then cross-link it, or to Colored tape attachment methods have been used in which colored nylon or other tape is attached between the cross-linked polyethylene coating, but the former method requires a lot of work to change the color, and the latter method requires less tape. There are disadvantages in that production efficiency decreases, such as requiring the work of inserting the color and stocking each color, and furthermore, the cost of the coloring material is high, resulting in high costs.

Therefore, as a simpler method than these methods, a surface coloring method in which a solvent-based paint using a vehicle is applied to the surface of cross-linked polyethylene can efficiently produce the required length of color identification wire. It has been proposed as the most effective method and is being used because it has advantages such as cost reduction without the complexity of color changing work during extrusion coating.

In other words, this surface coloring method uses a resin such as cyclized rubber, polyamide, or vinyl chloride as a vehicle, and then applies a paint that is dissolved in a solvent together with a coloring pigment, and then air-dries it or heats it above the melting point of the vehicle. This is a method in which the solvent is volatilized and the colored pigment is applied to the surface of crosslinked polyethylene along with the vehicle. However, with this type of surface coloring method, the adhesion of the paint to cross-linked polyethylene is poor, and in a friction test using felt with a load of 500 g, the paint film peeled off after approximately 1θ to several tens of reciprocating frictions, resulting in damage to electric wires and cables. When exposed to frequent bending, friction, etc., the colored paint is likely to peel off in a relatively short period of time. Furthermore, there are problems such as the coloring becoming unclear and environmental pollution caused by volatilization of the solvent in the paint during production, so that this method cannot be said to be satisfactory.

[Problem that the invention seeks to solve]

The present invention was developed by focusing on the above-mentioned problems in forming a colored coating on electric wires using polyolefin polymers, especially cross-linked polyethylene as insulation material. Conventionally, it was extremely difficult to form a strong colored coating on the surface. The purpose of the present invention is to provide a crosslinked polyethylene insulated wire in which a colored coating film with excellent adhesion is formed on the surface of a crosslinked polyethylene insulator by a relatively simple method.

Means for Solving Problem C] That is, the present invention includes a prepolymer having an acryloyl group and/or a methacryloyl group in the molecule, a monomer having the above group in the molecule, and It is a crosslinked polyethylene insulated wire having a colored coating film formed by applying a colored coating mixture of an oligomer and a pigment, and then curing the coating by irradiating it with ultraviolet rays.

In the present invention, examples of the prepolymer having an acryloyl group and/or methacryloyl group in the molecule include the compounds described below. That is, a terminal isocyanate compound obtained by reacting a diisocyanate compound and a polyol in advance is further added with β-hydroxyalkyl (meth)acrylate [(meth)acrylate is a general term for both acrylate and methacrylate. The same applies to the following descriptions and similar descriptions] in the molecule obtained by reacting
Addition polymerization compound having 1 or more (meth)acryloyl groups, obtained by ring-opening polymerization of dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and glycidyl (meth)acrylate.゛A linear polyester compound having many pendant (meth)acryloyl groups, a polyhydric alcohol having at least three esterifiable hydroxyl groups on adjacent carbon atoms, (meth)acrylic acid, dicarboxylic acid and its Polymerizable esters produced by coesterification with dicarboxylic acids selected from the group consisting of anhydrides, obtained by reacting melamine or benzoguanamine with formaldehyde, methyl alcohol, β-hydroxyalkyl (meth)acrylate, etc. Melamine poly(meth)acrylate resin, unsaturated polyester resin obtained by reacting glycidyl etherified polyhydroxy compound with (meth)acrylic acid, bisphenol type epoxy resin, novolak type epoxy resin, etc. Examples include epoxy poly(meth)acrylate resins obtained by reacting a resin containing two or more of them with (meth)acrylic acid.

In addition, examples of monomers having an acryloyl group and/or methacryloyl group in the molecule include 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate. Examples include acrylate, hexyldiglycol (meth)acrylate, (meth)acrylamide, methylol (meth)acrylamide, butoxymethyl (meth)acrylamide, and the like. Further, as oligomers having a group similar to the above monomer in the molecule, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1
, 6-hexanethiol di(meth)acrylate, neopentyl glycol di(meth)acrylate, bisoxyethylenated bisphenol A diacrylate, bisoxypropylenated bisphenol A diacrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and the like.

Therefore, the blending ratio of the monomer and/or oligomer to the prepolymer is 95:5 to 5:95 parts by weight, preferably 80:20 to 10:90 parts by weight.

If the blending ratio of the 7-mer and/or oligomer to the prepolymer is outside the above range, it will be difficult to obtain a sufficiently cured coating film. That is, if the prepolymer exceeds 95 parts by weight, the curability is good but the adhesion is poor, and if the prepolymer is less than 5 parts by weight, the curability in air is poor and the curing speed is extremely slow. descend.

In addition, the main resin having the above composition may contain various thermoplastic resins that are compatible with the monomers and oligomers, such as polyvinyl acetate resin and polyvinyl butyral resin, in order to alleviate curing distortion of the coating film and improve adhesion. , cellulose resin, vinyl acetate acrylate copolymer resin, xylene resin, saturated polyester resin, etc. can be blended.

Such a resin compounding agent has a content of 0.1 parts by weight per 100 parts by weight of the main resin.
It is desirable to add ~ioo parts by weight, preferably 0.5 to 30 parts by weight. If the amount of this compounding agent added is less than 0.1 part by weight, there will be almost no effect in alleviating the curing distortion of the coating film, and if it exceeds 100 parts by weight, the curability and solvent resistance of the coating film will be extremely reduced, so this is not desirable. do not have.

There are no particular restrictions on the coloring pigments added to the main ingredient of the present invention, but typical examples include titanium oxide, lead white, tin oxide, carbon black, zinc white, lead zinc oxide, red iron oxide,
Examples include red lead, chrome vermilion, cobalt red, yellow lead, yellow iron oxide, zinc yellow, titanium yellow, ultramarine blue, chrome green, Hansa yellow, permanent yellow, permanent orange, permanent red, phthalocyanine blue, and phthalocyanine green.

In addition to the photopolymerization initiator, sensitizer, filler, etc. that are generally added to photocurable coating compositions, the base composition may further contain a leveling agent, antifoaming agent, surfactant, etc. as necessary. , a polymerization inhibitor, a diluting solvent, etc. can be appropriately blended.

Among the above, photopolymerization initiators include benzophenone,
Benzyl, benzyl dimethyl ketal, 4,4'-bisdiethylaminobenzophenone, 2,2-jethoxyacetophenone, thioxanthone, alkylanthraquinone, 2,2-dimethoxy-2-phenylacetophenone, α-aziroxime ester, 1-phenyl-1 ,2
-Propanedione-2-(0-ethoxycarbonyl)oxime, ■-Phenyl-1,2-propanedione-2-
(0-benzoyl)oxime, chlorinated acetophenone derivative, 2-hydroxy-2-methylpropiophenone,
Examples include 4'-isopropyl-2-hydroxy-2-methylpropiophenone and the like alone or in a mixture of two or more.

In addition, sensitizers include aliphatic amines, amines containing aromatic groups, sulfur compounds such as sodium diethyldithiophosphate, NN-disubstituted-P-aminobenzonitrile compounds, and phosphorus compounds such as tri-n-butylphosphine. compounds, nitrogen compounds such as N-nitrosohydroxylamine derivatives, and the like.

The amount of these photopolymerization initiators and sensitizers is usually 0.05 to 10.0 parts by weight, preferably 0.05 to 10.0 parts by weight, and preferably 0.
．． It is added in an amount of 1 to 5 parts by weight.

Further, as the filler, fillers commonly used in paints can be used, such as extender pigments such as talc, mica, and calcium carbonate, and thixotropic agents (thixotropy imparting agents) such as silica, aluminum hydroxide, and bentonite.

The colored coating film of the crosslinked polyethylene insulated wire of the present invention is formed by applying a colored paint (hereinafter referred to as UV paint) made by blending each of the above components onto the crosslinked polyethylene insulator, and then irradiating it with ultraviolet rays. Ru.

This UV paint has a gel fraction of 50% or more, preferably 65%.
% or more of crosslinked polyethylene, and the coating thickness is preferably about 10 μm or less, preferably about 5 μm, and uniformly coated. That is, if the coating thickness is about 10 μm or more or if the coating thickness is non-uniform, this is not preferable because it will hinder the rapid formation of a cured coating film with a small amount of irradiation energy. Further, as a coating method, general methods such as spray coating, flow coating, roller coating, dip coating, etc. are employed.

Next, as an ultraviolet source for curing the applied UV paint, carbon arc lamps, mercury vapor lamps, ultraviolet fluorescent lamps, tungsten lamps, xenon lamps, argon glow lamps,
Sufficient curing can be achieved with short-time irradiation using a metal halide lamp or the like.

Although the amount of ultraviolet irradiation varies depending on the coating thickness, composition, etc., a satisfactory coating film can be formed with an irradiation energy of about 300 to 10,100 O/cd.

〔Example〕

The present invention will be further explained below with reference to Examples.

First, Table 1 summarizes the composition of the UV paint used in each example.

Notes to Table 1 *l is a prepolymer having two acryloyl groups in one molecule obtained by adding acrylic acid to a bisphenol-type epoxy resin.

*2 is isophorone diisocyanate 2-hydroxyethyl acetate Addition reaction of acrylate Two atoms in one molecule obtained Prepo with chloroyl group Rimmer.

*3 uses u, c, c, company product name Vinylai) VAGH.

Example 1 A first wire was attached to a cross-linked polyethylene (gel fraction approximately 80%) insulated wire having an outer diameter of 3.4 mm and running continuously at a speed of 50 m/min.
A UV paint having the composition and blending ratio shown in the table was applied to a film thickness of about 5 μm by dipping and squeezing out the excess paint. Next, a metal halide lamp (manufactured by Eye Graphics,
A crosslinked polyethylene insulated wire having a completely cured black beautiful colored coating was obtained by irradiating ultraviolet rays with an input power of 8 KW and an effective lamp length of 50 cm.

The colored coating film on this cross-linked polyethylene insulated wire was tested using an abrasion tester (Toyo Seiki Seisakusho Department P-V, F type Electr).
ic Wire Abrasion Te5ter)
As a result of performing a felt friction test under a load of 500g, there was no peeling of the paint film even after 1000 reciprocating frictions.
It showed strong adhesion and excellent wear resistance.

Example 2 A first wire was attached to a cross-linked polyethylene (gel fraction approximately 70%) insulated wire having an outer diameter of 4.0 and running continuously at a speed of 40 m/min.
A UV paint having the composition and blending ratio shown in the table was applied to a film thickness of about 5 μm by dipping and squeezing out excess paint. Next, the crosslinked polyethylene insulated wire was irradiated with ultraviolet rays under the same conditions as in Example 1 to obtain a completely cured crosslinked polyethylene insulated wire having a beautiful red colored coating.

A friction test similar to that in Example 1 was performed on the colored coating film on this cross-linked polyethylene insulated wire, and the result was that the coating did not peel off even after 1000 reciprocating frictions, indicating strong adhesion and excellent wear resistance. .

Implementation (PIJ3) After dip coating a cross-linked polyethylene (gel fraction approximately 65%) insulated wire with an outer diameter of 3.7 cm that runs continuously at a speed of 40 m/min with a UV paint having the composition and blending ratio shown in Table 1. The coating was applied to a thickness of about 10 μm by squeezing out the excess coating material.Then, it was irradiated with ultraviolet rays under the same conditions as in Example 1 to obtain a crosslinked polyethylene insulated wire having a beautiful blue colored coating that was completely cured. Obtained.

A friction test similar to that in Example 1 was performed on the colored coating film on this cross-linked polyethylene insulated wire, and the results showed that the coating did not peel off even after 1000 reciprocating frictions (showing strong adhesion and excellent wear resistance). Ta.

Comparative Example 1 A solvent-based paint consisting of 40% by weight of cyclized rubber resin, 10% by weight of cyanine blue as a coloring pigment, and 50% by weight of toluene as a solvent was coated with crosslinked polyethylene (gel fraction approximately 80%)! ! A cross-linked polyethylene insulated wire was obtained by applying a coating film to a thickness of about 10 μm by squeezing out excess paint after dipping the electric wire, and solidifying it by air drying.

A friction test similar to that in Example 1 was performed on the colored coating film on this crosslinked polyethylene insulated wire, and as a result, the coating peeled off after about 40 reciprocating frictions.

Comparative Example 2 A solvent-based paint consisting of 30% by weight of a vinyl chloride resin, 20% by weight of carbon as a coloring pigment, and 50% by weight of a ketone solvent was applied to a cross-linked polyethylene (gel fraction approximately 70%) insulated wire by dipping and then the excess was applied. A crosslinked polyethylene insulated wire having a colored coating was obtained by applying the coating to a thickness of about 10 μm by squeezing the coating and solidifying it by air drying.

A friction test similar to that in Example 1 was performed on the colored coating film on this crosslinked polyethylene insulated wire, and as a result, the coating peeled off after about 20 reciprocating frictions.

〔Effect of the invention〕

As is clear from the above Examples and Comparative Examples, the colored coating film of the crosslinked polyethylene insulated wire of the present invention has extremely strong adhesion and excellent wear resistance compared to colored coating films made of conventional solvent-based paints. The color recognition function can be maintained for a long period of time even when subjected to frequent bending or friction.

Moreover, since this colored coating film can be formed quickly with a small amount of ultraviolet ray irradiation, it is possible to implement it in-line with the crosslinked polyethylene insulated wire manufacturing process, thereby improving production efficiency. Furthermore, since UV paint is a solvent-free type, it has the advantage that there is no problem of environmental pollution due to solvent volatilization.

(Volunteer to write procedural amendments) February 7, 1985 □ Mr. Uga Michibu 1, Indication of the incident 1985 Patent Application No. 059428
No. 2. Name of the invention: Cross-linked polyethylene insulated wirework Person making the amendment: Relationship with 1. Patent applicant address: No. 4-28 Mita IT, Minato-ku, Tokyo Name (689)
) Yazaki Sogyo Co., Ltd. and 2 others 4, agent 5, W-Mr. Date Showa 1999
Day 6, Number of inventions increased by amendment Contents of amendment (Patent Application No. 60-059428) 1, W
On page 6, line 9 of the specification, "to adjacent carbon atoms" is deleted.

2. Same, page 9, line 2, correct "distortion" to "distortion".

3. Same, page 13, line 3, "irradiation amount" is corrected to "irradiation energy."

4, page 13, line 4, ``Correct approximately 300J to r300J.

5, same, page 14, Table 1 compound name column, 4 lines of countermeasures, “
``Carbon Black'' was changed to ``Carbon Black'', and the same three lines were used.
Correct "cyanine blue" to "phthalocyanine blue".

6, same page, page 16, line 6, ````Next'' is corrected to ``Next, upper and lower reflectors arranged in series in the traveling direction of the electric wire are provided''.

7, same, page 16, line 8, “ultraviolet rays” is changed to “ultraviolet rays 1
"From a distance of 0 cm."

8, same page, page 16, line 10, "obtained."

(Irradiation energy 420 mJ/aJ) Corrected as J.

9, same, page 17, line 5, "obtained." is corrected to "obtained. (irradiation energy 520 mJ/cd) J.

10, page 17, line 15, "10μ" is corrected to "5μ".

ii, same, page 17, line 18, "obtained." was replaced with "obtained."

(Irradiation energy 520 mJ/cd) Corrected as J.

12, same, page 19, line 12, "irradiation amount" is corrected to "irradiation energy."

Patent applicant: Yazaki Sogyo Co., Ltd. 2 others

Claims (2)

[Claims] (1) A prepolymer having an acryloyl group and/or methacryloyl group in the molecule, a monomer and/or oligomer having the above group in the molecule, and a pigment are blended on the surface of an insulator made of crosslinked polyethylene. A crosslinked polyethylene insulated wire characterized by having a colored coating film formed by applying a colored coating material and then curing it by irradiating it with ultraviolet rays. (2) The crosslinked polyethylene insulated wire according to claim 1, wherein the blending ratio of the prepolymer to the monomer and/or oligomer is 95:5 to 5:95 parts by weight.