JPH03218827A - complex - 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] [Industrial Application Field] The present invention is a vulcanized fiber board, which is an organic industrial material that is made by integrating natural fiber paper using the clumping action of glue oil such as zinc chloride, and a silicone fiber board. More specifically, the present invention relates to a composite body having a resin film formed thereon, and more specifically to a composite body in which the electrical properties of vulcanized fibers, particularly arc resistance, are improved by forming a silicone resin film on a vulcanized fiber plate.

[Conventional technology]

Vulcanized fiberboard is an organic industrial material that is made by laminating natural fiber paper and using glue such as zinc chloride. Can be punched, bent, drawn, etc., and has wear resistance and electrical insulation properties. Impact resistance. It is a material with excellent oil resistance, and is therefore suitable for use in light electrical equipment, heavy electrical equipment, various types of punctures, and mechanical parts. It has many uses, including transportation containers, spinning machines, sports, leisure, industrial safety equipment, and polishing.

Among these uses, vulcanized fiber is suitably used as an insulating material for earth leakage circuit breakers (commonly known as breakers) that protect electric wiring equipment and the like from large currents and overcurrents.

Vulcanized fiber has relatively excellent arc resistance against the arc that occurs when interrupting current with an earth leakage circuit breaker, and is made of pure natural cellulose, which does not easily generate carbon that can act as a conductive path for arcing. The generated gas is clean, there is no corrosion of equipment, no bad odor, etc., and it has a cooling effect when the constituent water is released and the gas produced by decomposition, has excellent processability, and is low in cost. This is because it has excellent properties as an insulating material for earth leakage circuit breakers. [Problems to be Solved by the Invention] However, vulcanized fibers do not satisfy the required characteristics of all breakers currently in use. The arc resistance (measurement method JIS K 6911) of vulcanized fiber is usually about 120 seconds, and for high voltage applications of 660V or higher, arc resistance. Insufficient heat resistance and water absorption. Hygroscopicity has also been pointed out as a drawback. Furthermore, if a flame retardant such as a phosphate ester flame retardant is added to impart flame retardancy to the vulcanized fiber, electrolytes will be included in the vulcanized fiber, resulting in poor arc resistance. There is also the problem that arc resistance and flame retardance are difficult to achieve.

Therefore, materials such as glass polyester and ceramics have conventionally been used as high voltage circuit breaker materials. However, since materials such as glass polyester and ceramic fibers have difficulty in processability, there has been a strong demand for improvements in the properties of vulcanized fibers, which have excellent processability, particularly in arc resistance.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a composite that effectively exhibits the original characteristics of vulcanized fiber, has excellent arc resistance, and can be suitably used as a material for circuit breakers. shall be.

[Means and effects for solving the problem] As a result of extensive studies to achieve the above object, the present inventor formed a silicone resin film on a vulcanized fiber board to create a composite of vulcanized fiber/silicone resin film. In this case, even if the silicone resin film is formed to a very small thickness compared to the thickness of the vulcanized fiber without impairing the moldability of the vulcanized fiber, the arc resistance of the vulcanized fiber is significantly improved. The arc resistance of flame-retardant vulcanized fiber containing a flame retardant is significantly improved, and it is possible to achieve the same arc resistance as that of a vulcanized fiber that is not flame-retardant. We discovered that it is possible to achieve both durability and arc resistance.
This is what led to the present invention. Therefore, the present invention provides a composite comprising a silicone resin film formed on a vulcanized fiber board.

The present invention will be described in further detail below.

The composite of the present invention uses a vulcanized fiber board as a base material, and has a silicone resin film formed on one or both sides of the base material. Here, as the vulcanized fiber serving as the base material of the present invention, any known organic industrial material can be used, which is an organic industrial material that is integrated with natural fiber paper using the clumping effect of glue such as zinc chloride. Further, as the vulcanized fiber serving as the base material of the present invention, one that has been flame retardant treated with a flame retardant can also be suitably used. In this case, flame retardants include phosphate ester flame retardants, chlorine flame retardants, bromine flame retardants, etc. When these flame retardants are made into glue with zinc chloride etc., zinc chloride By adding to an aqueous solution of
It can be easily flame retardant treated. Next, the silicone composition for forming the silicone resin film is not particularly limited, but it can be used without impairing the good processability of the vulcanized fiber board, and which can be used to punch out the composite. It is important to maintain sufficient toughness against external mechanical stresses such as shearing and bending, and to prevent the silicone resin film from pulverizing into powder and adhering to conductive parts on the surface of the device. Therefore, silicone rubber coatings are preferable to hard and brittle coatings. Silicone rubber compositions that can form this silicone rubber film include condensation-curing silicone rubber compositions, addition-curing silicone rubber compositions,
Examples include organic peroxide-curable silicone rubber compositions and ultraviolet-curable silicone rubber compositions. Workability.
Various materials can be used depending on arc resistance, film strength, etc.

In addition, in order to sufficiently adhere the silicone resin film onto the vulcanized fiber board and form a composite, it is preferable to perform a brimer treatment on the surface of the vulcanized fiber, but from the viewpoint of the manufacturing process, it is preferable to use a self-adhesive silicone rubber composition. It is effective to omit the brimer processing. Any of these silicone rubber compositions can have a known composition, and commercial products such as KE45TS (condensation curing self-adhesive silicone rubber composition) and KE1800TA/TB manufactured by Shin-Etsu Chemical Co., Ltd. (Addition-curing self-adhesive silicone rubber composition), KE121
2A/B/C (addition-curing self-adhesive silicone rubber composition). KE951U (organic peroxide-curable silicone rubber composition), Kll! 1955A/B
(Addition-curable silicone rubber composition) and the like.

In the composite of the present invention, the thickness of the silicone resin film is not particularly limited, but may be any thickness depending on the required arc resistance, and can usually be 5 to 1000 μm thick. In particular, when used as an insulating material for high-voltage circuit breakers, the thickness is preferably 50 μm or more.

As a method for forming the silicone resin film as described above, a conventional method depending on the type of composition can be adopted,
The silicone composition can be applied to the vulcanized fiber board as it is, or if necessary, it can be diluted with a solvent and applied to the vulcanized fiber board to obtain a constant film thickness.

The application methods include spray application and brush application. Coater application. Calendar molding. The method can be appropriately selected from known methods such as disop coating and screen printing depending on the coating speed and viscosity of the silicone resin. The curing method after application may be a conventional method depending on the curing method of the composition.

〔Effect of the invention〕

As explained above, the composite of the present invention has very good arc resistance by forming a silicone resin film on vulcanized fiber, and can also have both flame retardancy and good arc resistance. , combined with the good moldability of vulcanized fiber, makes it particularly suitable for use as an insulating material for high-voltage circuit breakers.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples.

〔Example〕

First, vulcanized fibers A and B were manufactured as follows.

<Manufacture of vulcanized fiber A> Cotton cellulose paper (200 x 500 x O.4 cranes) was immersed in a 70% zinc chloride aqueous solution for 5 minutes, then 4 sheets of this paper were stacked on top of each other and aged for 60 minutes to coagulate and integrate. The paper was washed with water for 20 minutes. Next, it was dried at 120° C. for 2 hours to produce vulcanized fiber A (thickness: 1.6 mm).

<Manufacture of vulcanized fiber B (flame retardant)> In the manufacture of vulcanized fiber A above, the same procedure was used except that a mixed aqueous solution of 70% zinc chloride aqueous solution and 5% tetrakis (hydroxymethyl) phosphonium chloride was used. A flame-retardant vulcanized fiber B was manufactured using the following methods. Next, silicone rubber compositions (1) to (V) shown below were applied to the surfaces of the vulcanized fibers A and B obtained above by the method shown in Table 1 to form a cured film. The arc resistance of the vulcanized fiber on which the silicone film was formed was tested according to JIS-K-6911, and the adhesive strength (shear adhesive strength) of the silicone film was tested using the method described below. The results are also listed in the same table.

After applying the silicone rubber composition shown below on a vulcanized fiber with a width of 25 mm, the coated surfaces were overlapped and brought into close contact (overlap width 10 fi), and after curing under the conditions shown in the table, The shear adhesive strength was measured at a tensile rate of 50 days/sin.

These results show that compared to vulcanized fibers that do not have a silicone rubber coating, vulcanized fibers that have a silicone rubber coating with a thickness of only 30 to 200 μm have significantly improved arc resistance, and are particularly difficult to use. It is recognized that the effect is remarkable with flammable vulcanized fiber B.

Applicant: Shin-Etsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A composite made of a silicone resin film formed on a vulcanized fiber board.