JPS643287B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for applying insulation coating treatment to an arbitrary shape on the outer periphery of an optical fiber bar code.

Hereinafter, a case will be described in which the present invention is applied to an insulating coating of an optical fiber bar code.

Recently, the range of applications of optical fibers, photodiodes, etc. has been increasing, and they are being used in various electrical devices and devices. For example, one example of the application of optical fibers to high-voltage electrical equipment is the application to failure detection devices such as power capacitors, in which the electrical equipment body is installed on top of a pedestal insulated with ceramic or resin insulators.

An application example will be specifically explained with reference to FIG.

In Figure 1, 1 is an electrical device using an insulating stand such as an electrical capacitor, 2 is the main body of the electrical device, 3 is an insulator, 4 and 5 are the upper and lower frames of the insulating stand, and 6 is the main body of the electrical device. 2 is a protection device generating section that has a function of electrically detecting the occurrence of an abnormality and converting the signal into an optical signal; 7 is a protection device light receiving section that receives the signal and operates an electric contact; 8 is a section between 6 and 7 mentioned above; It is an optical fiber barcode that connects the

Optical fiber barcodes are usually cylindrical cords coated with flexible organic materials such as polyethylene, and there are no commercially available cords with insulation coatings that take creepage voltage into consideration, such as cords with pleated coatings. This is the current situation, and when applying a coating with irregularities such as pleats, continuous production by extrusion molding or the like is almost impossible.

However, when optical fiber barcodes are applied to high-voltage electrical equipment such as those mentioned above, ground voltage is constantly applied between both ends of the optical fiber barcodes.
In reality, in order to protect the coating surface from staining and deterioration or creeping dielectric breakdown during rain, insulation treatment as shown in FIG. 2 is applied and used.

In FIG. 2, 3 is a ceramic or resin insulator having through holes, and 8 is an optical fiber bar cord that passes through the insulator 3. 9 is resin injected for corona prevention or waterproofing.

Optical fiber barcodes that have been insulated as shown in Figure 2 require insulators depending on the length and diameter of the optical fiber barcode, and ceramic insulators in particular are susceptible to cracking due to earthquakes and other vibrations. Since this is likely to occur, sufficient anti-vibration measures are required.

Furthermore, after inserting the optical fiber barcode, it is necessary to fill the air gap in the insulator through hole and inject resin for waterproofing purposes.

The conventional insulation coating method described above takes a long time to manufacture, is expensive, and is not sufficiently waterproof.

Furthermore, the connection of optical fiber barcodes always involves a heavy insulator, which significantly reduces work efficiency when assembling electrical equipment.
Furthermore, it was also impossible to connect the optical fiber bar cord in a bent state.

The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide an extremely simple and highly reliable insulation coating treatment method when, for example, an optical transmission line is incorporated into high-voltage electrical equipment.

That is, the present invention relates to a hydrogenated product of a polyhydroxybutadiene polymer having a melting point of 40 to 130°C and solid at room temperature, and a hydrogenated product of the formula (): 2,4-toluene diisocyanate represented by
A molding material made of a dimer and an active tertiary amine catalyst for urethane polymerization is preformed into a predetermined shape, and the preformed molded product and the insulating coating are placed in a mold and heated with a solvent. The present invention relates to a method for insulating a cable connection portion by hardening it.

Active No. 3 for urethane polymerization used in the present invention
Examples of the class amine catalyst include triethylenediamine, triethylamine, dimethylaminophenol, tris(dimethylaminomethyl)phenol, and pyridine.

The hydrogenated product of polyhydroxybutadiene polymer, which is the main ingredient of the molding material used in the present invention, is a thermosetting resin, and the main ingredient is a 2,4-toluene diisocyanate dimer represented by the formula (), which is a curing agent. The ratio is the number of moles of isocyanate groups in the curing agent to the number of moles of hydroxyl groups in the base agent.
A ratio of NCO/OH=0.8 to 1.2 is preferred. The ratio of the base agent to the catalyst is preferably 0.1 to 0.5 parts by weight based on 100 parts by weight of the base agent.

The thermosetting resin used for the molding material has a melting point within the above range, and the molding material consisting of the base resin, curing agent, and catalyst can have a shelf life of one month or more (melting point temperature It has the ability to flow due to

If the melting point of the hydrogenated polyhydroxybutadiene polymer used in the present invention is lower than 40°C, it will tend to flow at room temperature and cannot maintain its preformed shape. In addition, since it has adhesive properties, workability is significantly reduced. On the other hand, when the temperature is higher than 130°C, the melting temperature during molding becomes high, so a gelation reaction occurs during melting, resulting in poor appearance such as resin missing parts and voids, which is not preferable.

The preformed molded product according to the present invention is placed inside a mold so as to cover the cable connection portion, and then heated and hardened. Further, during heat curing, the sum of the volumes of the preformed molded product and the cable connection part must be equal to or larger than the volume of the hollow part of the mold so that voids do not occur inside.

Since the mold only needs to be heated by placing a preformed molding material therein for covering the cable connection, a relatively simple structure is sufficient.

An embodiment of the present invention will be described below with reference to FIGS. 3, 4, and 5.

FIG. 3a shows an example of the manufacturing process of a preformed molded article used in the present invention, and FIG. 3b is an explanatory diagram illustrating the content of the manufacturing process. In this example, first, the hydrogenated product of polyhydroxybutadiene polymer used as the main ingredient and the curing agent 2,
4-Toluene diisocyanate dimer prepared so that the molar ratio of isocyanate groups to hydroxyl groups was equal was mixed in a heating stirring device 10.
After mixing, the mixture is cooled to room temperature, and kneaded in a solid state using two rolls 12, and the above-mentioned main agent such as triethylenediamine is added as a urethane polymerization active catalyst.
It is added at a ratio of 0.3 parts by weight to 100 parts by weight and kneaded until uniformly dispersed. Mixture 11 after kneading
is passed through a calender roll 13 and formed into a sheet having a desired thickness.

Next, the mixture 11 formed into a sheet shape is cut by the cutting cutter 14, and the mixture 11 is cut into 11a or 11.
A preformed molded product as shown in b can be obtained.

Next, FIG. 4 shows a partial sectional view of the two-part simple mold used in this example. 15a is the main body of the upper mold, and 15b is the main body of the lower mold. Note that both are equipped with a heating device (not shown). 16 is a clamp for clamping the mold, 17a and 17b are means for fixing the optical fiber cord 8, and 18 is a molding material in a molten state.

To carry out molding, first, the upper mold 15a and the lower mold 15b are opened, and a preformed molded article is placed in each molded article, and heated to the melting temperature of the molded article. Next, insert the optical fiber barcode 8 into the lower mold 15.
b and fixed to the mold 15 with fasteners 17a and 17b, and then the upper mold 15a is placed on the lower mold 1.
5b, the mold is clamped using a clamping tool 16, and the mold is cured by holding at a predetermined temperature (for example, at 140 to 160° C. for 1 to 2 hours). After cooling, the mold is opened and the molded product is taken out.

FIG. 5 is a sectional view showing the insulating coating of the optical fiber bar code after demolding. Reference numeral 19 represents an insulating coating after curing, and reference numerals 8a and 8b represent connection terminals to photosensitive elements, etc., provided at both ends of the optical fiber bar code 8, respectively.

According to the method of the present invention, unlike the conventional method shown in FIG. It is possible to form an insulating coating even after connecting terminals etc.
Waterproofing is also extremely effective compared to conventional methods because it is an integrally molded part. Moreover, it is easy to mold as it can be molded using an extremely simple mold as shown in FIG. 4, and has the great advantage that it can be performed on-site as long as there is a heating source (such as an electric heater).
It is sufficient that the mold clamping force of the mold is extremely low, such as one that can be tightened with a fingertip, or an upper mold that uses only its own weight and does not use any particular clamping tool.

The insulating coating method according to the present invention is suitable for insulating coating of transmission paths between different potentials of all kinds of electrical equipment,
In particular, when applied to the insulation coating of the signal transmission path from the ultra-high voltage section to the ground potential, a significant effect in terms of safety can be obtained.

Incidentally, in the above explanation, the case where the present invention is applied to an optical transmission member has been explained, but it goes without saying that the present invention is not limited to this.

As explained above, according to the present invention, there is an effect that a high-performance insulation coating can be easily obtained.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of the application of the optical transmission member;
Figure 2 is a cross-sectional view showing an example of insulation coating using the conventional method.
FIG. 3a is a diagram showing the manufacturing process of a preformed molded article according to an embodiment of the present invention, FIG. 3b is an explanatory diagram illustrating the contents of the process shown in FIG. 3a, and FIG. FIG. 5 is a partial sectional view showing an example of manufacturing using a simple mold according to an embodiment of the invention, and FIG. 5 is a diagram showing an optical fiber bar code coated with insulation obtained by an embodiment of the invention. In the figure, 8 is an optical fiber barcode, 11a, 11
b is a preformed molded product, 15 is a mold, 1
9 is an insulating coating. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A hydrogenated product of polyhydroxybutadiene polymer having a melting point of 40 to 130°C and solid at room temperature, formula (): 2,4-toluene diisocyanate represented by
A molding material made of a dimer and an active tertiary amine catalyst for urethane polymerization is preformed into a predetermined shape, and the preformed molded product and the insulating coating are placed in a mold and heated and melted. An insulation coating method characterized by curing. 2. The insulation coating method according to claim 1, wherein the insulation coating is an optical fiber bar code.