JPH0133886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for applying an arbitrary shape of insulation coating to a fragile and fragile optical transmission member.

[Prior Art/Problems to be Solved by the Invention] Recently, the range of applications of optical fibers, photodiodes, etc. has been increasing steadily, and they are being applied to various electrical appliances and devices. For example, one example of the application of optical fiber to high-voltage electrical equipment is its application to failure detection devices such as power capacitors, in which the electrical equipment itself is installed on top of a stand insulated with ceramic or resin insulators.

The application example will be specifically explained based on FIG. 1.

In Fig. 1, 1 is the main body of electrical equipment using an insulating stand such as a power capacitor, 3 is an insulator, 4 and 5 are the upper and lower frames of the insulating stand, and 6
electrically detects the occurrence of an abnormality in the electrical equipment main body 1,
7 is a protection device generating section that has the function of converting the signal into an optical signal, 7 is a protection device light receiving section that receives the signal and operates an electrical contact, and 8 is an optical transmission member (hereinafter referred to as an optical fiber) that connects the above 6 and 7. (referred to as a code).

Normally, the optical fiber bar code 8 is a cylindrical code coated with a flexible organic material such as polyethylene. For example, there are no commercially available cords with a pleated insulation coating that takes into account the creepage withstand voltage. This is the current situation. Furthermore, if a coating is applied that has irregularities such as pleats, continuous production by extrusion molding or the like is almost impossible.

However, when the optical fiber barcode 8 is applied to high-voltage electrical equipment as described above, ground voltage is constantly applied between both ends of the optical fiber barcode, resulting in contamination and deterioration of the coating surface or creeping insulation breakdown during rain. In reality, in order to protect the device from damage, it is used with an insulation treatment as shown in FIG.

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

For optical fiber barcodes 8 that have been insulated as shown in Figure 2, an insulator is required depending on the length and diameter of the optical fiber barcode 8. Particularly in the case of ceramic insulators, it is difficult to resist earthquakes and other vibrations. As a result, cracks are likely to occur, so sufficient anti-vibration measures are required.

Also, after inserting the optical fiber barcode 8,
It is necessary to fill the air gap in the insulator through hole and inject resin for waterproofing purposes.

The conventional insulating coating method for optical transmission members as described above takes a long time to manufacture, is expensive, and is not sufficiently waterproof. Furthermore, a heavy insulator is always attached to the connection, which significantly reduces work efficiency when assembling electrical equipment, etc.
It was also impossible to connect the optical fiber barcode in a bent state.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and includes (a) a hydrogenated product of a polyhydroxybutadiene polymer having a melting point of 40 to 130°C and the general formula (): (In the formula, R ₁ , R ₂ and R ₃ are the same or different, each is an alkyl group having 1 to 3 carbon atoms, and n is an integer of 1 to 4) or (b) melting point 40 A thermosetting resin composition (hereinafter referred to as (a) or (b) thermal (referred to as curable resin composition)
The present invention relates to an insulating coating method for an optical transmission member, characterized in that the optical transmission member is vacuum degassed, preformed into a predetermined shape, placed in a mold together with the optical transmission member, and heated and molded at low pressure.

The method of the present invention is a new simple molding method that eliminates the above-mentioned drawbacks. According to the method of the present invention, it is extremely simple and highly reliable when, for example, incorporating an optical transmission line into high-voltage electrical equipment. Become.

[Example] An example of the present invention will be described based on FIGS. 3 and 4.

Figure 3 shows an example of a manufacturing device for obtaining a preformed molding material, in which 10 is a normal vacuum stirring device, and 11 is a device used for insulation coating (a).
Or the thermosetting resin composition (b). Reference numeral 12 denotes a mold for the preform, but a plastic case or the like with excellent mold releasability may also be used. The thermosetting resin composition, which has been sufficiently vacuum degassed at a temperature above the melting point using the vacuum stirring device 10, is placed in the mold 1.
After being injected into the mold 2, it is cooled to room temperature and removed from the mold to obtain a preformed molded product 13. The thermosetting resin composition used for manufacturing the molded article 13 is solid at working temperature, and is preferably maintained at room temperature or low temperature (below 0°C) to maintain a pot life of, for example, one month or more (near the melting point). It has the ability to flow when heated and can be used normally).

A specific example of the thermosetting resin composition includes a main ingredient made of a hydrogenated polyhydroxybutadiene polymer having a melting point of 40 to 130°C, and a general formula (): (In the formula, R ₁ , R ₂ and R ₃ are the same or different, each is an alkyl group having 1 to 3 carbon atoms, and n is an integer of 1 to 4) with a curing agent consisting of an isocyanate compound. , or melting point 40-100
C. and a mixture of a main agent made of an epoxy resin having two or more epoxy groups in the molecule and a curing agent made of a modified amine of boron trifluoride.

Examples of the epoxy resin having two or more epoxy groups in the molecule, which is one of the main ingredients used in the present invention, include Epicote 1001 (manufactured by Ciel Corporation),
Examples include GY6071 (manufactured by Ciba), as well as Epicote 828, Epicote 1004, and Epicote 1007.
Examples include epoxy resins whose melting points are adjusted to 60 to 90°C using DER438, DER431 (all manufactured by Dow), etc. (all manufactured by Ciel).

The isocyanate compound represented by the general formula () used as a curing agent in the present invention includes:
For example, 3-isocyanatomethyl-3,5,5
-trimethylcyclohexyl isocyanate, 3
-isocyanate ethyl 3,5,5-trimethylcyclohexyl isocyanate, 3-isocyanate propyl-3,5,5-triethylcyclohexyl isocyanate, and the like. Also,
As a modified amine block complex salt of boron trifluoride,
Tateba Anchor 1170, Anchor 1171, Anchor
Examples include 1040 and Anchor 1222 (both manufactured by Anchor Chemical).

The hydrogenated product of the polyhydroxybutadiene polymer and the epoxy resin, which are the main ingredients of the thermosetting resin composition used in the present invention, are both thermosetting resins, and the hydrogenated product and the epoxy resin of the polyhydroxybutadiene polymer are cured. The ratio of the isocyanate compound represented by the general formula () which is the agent is preferably such that the ratio of the hydroxyl groups present in the main agent to the isocyanate groups present in the curing agent is NCO/OH = 0.8 to 1.2. In addition, the ratio of the epoxy resin as the main ingredient to the modified amine block complex salt of boron trifluoride as the curing agent is such that the equivalent ratio of the epoxy resin to the curing agent is 1/1.
It is preferable to become

The thermosetting resin has a melting point within the above range, and the thermosetting resin composition, which is a molding material consisting of a base resin and a curing agent, can be stored for one month or more at room temperature or at a low temperature below 0°C. It has a usage time.

The melting point of the hydrogenated polyhydroxybutadiene polymer and epoxy resin used in the present invention is 40°C
If the temperature is lower, it will flow easily at room temperature and will not be able to maintain its preformed shape. Moreover, since it has adhesive properties, workability is significantly reduced.
On the other hand, when the temperature is higher than 130℃ for hydrogenated polyhydroxybutadiene polymers and 100℃ for epoxy resins, the melting temperature during molding becomes high, so a gelation reaction occurs during melting, leaving resin missing parts and voids. Both are unfavorable because they cause poor appearance.

The preformed molded product of the present invention is placed inside a mold so as to cover a desired portion (part or all) of the light transmission member, and is heated and hardened. Further, during heat curing, it is preferable that the sum of the volumes of the preformed molded product and the light transmission member be equal to or larger than the volume of the hollow part of the mold so that voids are not generated inside.

A relatively simple structure is sufficient for the mold, since it is sufficient to place a preformed molded product for covering the light transmission member inside the mold and heat it. Further, since the preformed molded product is vacuum degassed as described above, inclusion of voids can be prevented.

Next, FIG. 4 shows a partial cross-sectional view of a simple mold that can be divided into two parts used in the above embodiment of the present invention.

In the figure, 14a is the main body of the upper mold, and 14b is the main body of the lower mold. Although not shown, both are equipped with a heating device. 15 is a fastener for clamping the mold, 16 is a fastener for fixing the optical fiber bar code, and 18 is a thermosetting resin composition.

In order to carry out molding, first, the upper mold 14a and the lower mold 14b are opened, a preformed molded article is placed in each molded article, and the molded articles are heated to the melting temperature of the molded article. Next, insert the optical fiber barcode 8 into the lower mold 1.
4b and fixed to the mold using fasteners 16a and 16b, then the upper mold 14a is placed together and the mold is clamped using the fastener 15, and maintained at a predetermined temperature (for example, 140 to 160°C). Cure for 1-2 hours). After cooling, open the mold and take out the molded product.

FIG. 5 is a sectional view showing the insulating coating of the optical fiber bar code after demolding. Reference numeral 18 indicates an insulating coating after curing, and reference numerals 8a and 8b indicate connection terminals provided at both ends of the optical fiber bar code 8, respectively, to a photosensitive element or the like.

According to the above-mentioned method of the present invention, there is no need for operations such as injecting resin after passing the optical fiber code through the through hole of the insulator as in the conventional method shown in FIG. It is possible to form an insulating coating even after connecting terminals, etc., and the waterproofness is also extremely superior compared to conventional methods because it is an integrally molded part. Moreover, it is easy to mold because it can be molded using an extremely simple mold as shown in FIG. 4, and it has the great feature that it can be worked on site as long as there is a heating source (such as an electric heater). Furthermore, voids are not mixed into the thermosetting resin composition that has been thermoformed. 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 one that uses only the dead weight of the upper mold and does not use any particular clamping tool.

The simple molding method of the present invention is suitable for insulating coatings on transmission lines between different potentials in all kinds of electrical equipment, and in particular, when applied to insulating coatings on signal transmission lines from ultra-high voltage parts to ground potential, it has great safety benefits. You can get the effect.

[Effects of the Invention] According to the method of the present invention, it is possible to easily apply a high-performance insulating coating in an arbitrary shape to a fragile and fragile member such as an optical transmission member.

[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. 3 is an explanatory diagram showing an example of manufacturing a preformed molded article used in the present invention, FIG. 4 is a sectional view showing an example of manufacturing according to an embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view showing the optical transmission member provided with the obtained insulating coating. In the figure, 8 is a light transmission member, 13 is a preformed molded product, 14 is a mold, and 18 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) A hydrogenated product of a polyhydroxybutadiene polymer having a melting point of 40 to 130°C and the general formula (): (In the formula, R ₁ , R ₂ and R ₃ are the same or different, each is an alkyl group having 1 to 3 carbon atoms, and n is an integer of 1 to 4) or (b) melting point 40 A solid thermosetting resin composition consisting of an epoxy resin having two or more epoxy groups in the molecule and a modified amine of boron trifluoride is vacuum defoamed at ~100°C and preformed into a predetermined shape. 1. A method for insulating an optical transmission member, the method comprising: subsequently placing the optical transmission member in a mold and heat-molding the optical transmission member at low pressure.