JPS5889677A - Sealing compound of resin for feedthrough - Google Patents

Abstract

PURPOSE:The titled sealing compound of resin useful for submarine optical repeaters, etc., having improved water pressure resistance and hermetic properties, comprising a curing agent consisting of a polyamide resin obtained by reacting an alkylenediamine, etc. with a dimer of a unsaturated fatty acid and an epoxy resin. CONSTITUTION:An epoxy resin(e.g., bisphenol A type epoxy resin, novolak type epoxy resin, etc.) is blended with a curing agent consisting of a polyamide resin obtained by reacting an alkylenediamine such as ethylenediamine, etc. or polyethylenetriamine such as triethylenetetramine, etc. with a dimer of an unsaturated fatty acid, to give a sealing compound of resin for feedthrough.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin-sealed feed-through suitable for use in submarine optical repeaters and the like, and particularly to a resin-sealed feed-through material with excellent water pressure resistance and airtightness.

As a method of fixing an optical fiber to a feedthrough, there is a method of injecting a thermosetting resin into the feedthrough and curing it to seal it. As the sealing resin, an epoxy adhesive is used, comprehensively judged from the characteristics of moisture permeability, adhesive strength, and optical fiber optical loss. Here, the properties of the epoxy adhesive after curing vary greatly depending on the type of curing agent used, so it is necessary to select a curing agent that is suitable for the purpose. Therefore, as a curing agent for epoxy adhesives for feedthroughs that need to reduce optical loss in optical fibers, cured products with low Young's modulus and excellent flexibility, low curing shrinkage, and low internal stress are recommended. Polyamide resins are used that give The structure of a feedthrough in which an epoxy resin composition such as the one described above is used is shown in the accompanying drawings. Here, 1 is a feed-through type, 2 is an optical fiber, 2A is optical fiber glass, and 3 is a sealing resin.

The feedthrough type 1 and the optical fiber 2 are bonded and sealed with a sealing resin 3.

The coating of the optical fiber 2 is partially removed to create a structure in which the fiber glass 2A and the sealing resin 3 are directly bonded to each other, thereby improving adhesiveness.

In the attached drawings, the upper side of the feedthrough is the cable side, and the lower side is the inside of the repeater. Feedthrough with this structure has a simple manufacturing process and is suitable for feedthrough type 1.
Moreover, there is an advantage that the initial adhesive strength between the optical fiber glass 2A and the sealing resin 3 is also large. However, conventional epoxy adhesives using polyamide 9 resin curing agents have poor water resistance and moisture resistance, and when used for a long period of time under high humidity conditions, they may cause damage to feed-through type 1 and optical fiber glass. The adhesion strength of the sealing resin 3 to the two people decreases, and water and moisture easily enter the submarine optical repeater and the like through these interfaces. Therefore, there was a drawback that the water pressure resistance was poor in withstanding water pressure applied to the feedthrough due to trouble such as cable cutting. In addition, the sealing resin itself had a high moisture permeability and poor airtightness.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks and provide a feed-through resin sealant having excellent water pressure resistance and airtightness.

That is, to summarize the present invention, the present invention relates to a feedthrough resin comprising a curing agent made of a polyamide resin obtained by reacting an alkylene diamine or a polyalkylene polyamine with a dimer of unsaturated fatty acids, and an epoxy resin. Regarding sealing material.

In the present invention, as a curing agent for an epoxy resin composition, a polyamide resin (
Product examples: Perzamide V140, V-125, ■-11
5; manufactured by Henkel Japan Co., Ltd.) to constitute the sealing resin 3. A suitable example of an alkylene diamine is ethylene diamine, and a suitable example of a polyalkylene polyamine is a polyethylene polyamine such as triethylenetetramine. In order to improve the water pressure resistance due to the structure of the feed-through, it is necessary to provide sufficient space between the feed-through mold 1 and the sealing resin 6, and between the optical fiber glass 2A and the sealing resin 3, even when submerged in water and under high humidity conditions. It is necessary to obtain sufficient adhesive strength. In particular, in conventional products, it has been found that the adhesive strength between the feed-through mold 1 and the sealing resin 3 is significantly reduced due to the influence of moisture, so it is necessary to improve the adhesive strength to the feed-through mold 1. Furthermore, in order to improve the airtightness of the feedthrough, it is necessary to use a resin with low moisture permeability as the A-blocking resin 3.

The present inventors have taken advantage of the characteristics of an epoxy resin composition containing a polyamide resin curing agent that provides a cured product with excellent removability and low curing shrinkage, and has made it more durable under water immersion and high humidity conditions than conventional products. By using an epoxy resin composition that has excellent adhesive strength (hereinafter abbreviated as water-resistant and moisture-resistant adhesive strength) and low moisture permeability, it was possible to significantly improve the water pressure resistance and airtightness of the feedthrough.

Hereinafter, the present invention will be further described in detail by giving examples thereof and comparative examples with conventional products. However, the present invention is not limited to these examples.

Example Bisphenol A-based epoxy resin (Product example: Ezaki Ebiko 828: manufactured by Yuka Shell Epoxy Co., Ltd.) was used as the main ingredient, and as a hardening agent, it was added to 1 mole of dimer of an unsaturated fatty acid mixture containing riluic acid as the main component. A polyamide resin (product example: Persamide V-140, manufactured by Henkel Japan Co., Ltd.) prepared by mixing and reacting 2 moles of triethylenetetramine (TTA), which is an example of a polyalkylene polyamine, is used. The base material and the curing agent are mixed at a weight ratio of 2:1, and after defoaming, the mixture is injected between the feed-through mold 1 and the optical fiber glass 2A. The adhesive was left at 60° C. for 7 hours to cure, and then allowed to cool.

Table 1 shows the initial shear adhesive strength of the sealing resin 3 with the feed-through type 1 in the feed-through fabricated in this manner and the rate of decrease in shear adhesive strength after immersion in 80°C hot water for 6 hours, together with comparative examples. Shown below.

Table 1 In the examples, the initial shear bond strength is the same as that of the conventionally used comparative example, but the rate of decrease in shear bond strength due to the influence of hot water is less than 1/10, and the water and moisture resistant adhesive strength is remarkable. improved. For this reason, the water pressure resistance withstanding the applied paddy field after being used for a long period of time under water immersion or high humidity conditions and undergoing deterioration has been significantly improved.

Next, Table 2 shows the moisture permeability of the feedthrough produced by this example and the moisture permeability of the resin itself, together with comparative examples.

The moisture permeability of the cured product of the conventional evo\xy resin composition for feedthrough shown in the comparative example in Table 2 was 9. OX 10-”
97cm・sec・cmHta, and the moisture permeability of the feedthrough made using this is 38×10”cc/sec・m
Hf, whereas the moisture permeability in the example of the present invention was 5. OX 10-” cc 7 seconds.・tan H
f, and the airtightness was significantly improved.

As described above, by improving the water pressure resistance and airtightness of the feedthrough, reliability as a component has also been significantly improved.

In the present invention, the epoxy resin is not limited to bisphenol A-based epoxy resin, and the curing agent is not limited to polyamide resin obtained by reacting a dimer of an unsaturated fatty acid mixture with 'I'TA. As the epoxy resin, a novolac type epoxy resin or a glycidyl ester type epoxy resin can be used, and as a curing agent, a polyamide resin made by reacting a dimer of an unsaturated fatty acid mixture with ethylene diamine, or a dimer of an unsaturated fatty acid mixture can be used. This can be achieved by using a polyamide resin (product example: Persamide V-115, 125, manufactured by Henkel Japan Co., Ltd.) prepared by reacting a polymer with diethylene tri'amine.

As explained above, according to the present invention, the water pressure resistance and airtightness, which were conventional problems in resin-sealed feedthroughs, can be significantly improved, and the present invention can be applied to feedthroughs for submarine optical repeaters. This has the advantage of greatly improving the reliability of submarine optical repeaters.

[Brief explanation of the drawing]

The accompanying drawing is a cross-sectional view of the feedthrough. 1: Feed-through type, 2: Optical fiber, 2A: Optical fiber glass, 5: Sealing resin patent applicant Hiroshi Nakamoto, agent of Nippon Telegraph and Telephone Public Corporation

Claims (1)

[Claims] 1. A resin sealing material for feedthrough comprising a curing agent such as a polyamide resin obtained by reacting an alkylene diamine or a polyalkylene polyamine with an unsaturated fatty acid dimer, and an epoxy resin.