JPS5817312Y2 - electrical insulation materials - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electrical insulating material, and more specifically to a material in which an electrical insulating material made of adjusted granular mica and a heat-resistant base material is laminated with a reinforcing agent layer interposed therebetween. It is related to.

In recent years, pulp-like particles obtained from synthetic polymers have attracted attention as electrical insulating materials because of their favorable heat resistance and electrical properties.

Examples of these specific conventional techniques include 1. Special Public Sho 3
5-11851 and Japanese Patent Publication No. 43-20421.

The former describes pulp-like particles, and Zenni describes a high-temperature-resistant sheet-like structure suitable for electrically insulating paper consisting of an entangled mixture of granular mica and substantially unfused aromatic polyamide fibrids.

However, when these are used as electrical insulating materials, their versatility in terms of insulation, impregnating properties, and peeling resistance of mica is still unsatisfactory.

, that is, for structures based on Japanese Patent Publication No. 43-20421,
Although mica and aromatic polyamide are used as a mixture, in this embodiment, from the blending ratio alone, if there is a large amount of mica,
It easily peels off due to friction, and the structural strength during molding is significantly reduced, making workability extremely difficult.

On the other hand, if the amount of aromatic polyamide is increased, the insulating properties associated with impregnating properties will become difficult, and if the content is moderate, the effect will be insufficient in all properties, which is not preferable.

More specifically, problems arise when applied to mica paper, for example.

In other words, mica paper is usually bonded to an insulating substrate using varnish to supplement its strength, but in addition to the above-mentioned disadvantages, it also causes corona generation due to voids in the varnish layer, making its practicality difficult. It causes inconvenience.

Based on these, the present inventors have already adhered a layer 2 consisting of 91% by weight or more of granular mica and 9% by weight or less of a heat-resistant polymer onto one side of the heat-resistant base material layer 1 by heating and pressing. Electrical insulation material
165800).

However, in this range, we focused on the structural strength among the various items to be improved as a material, and as a result of intensive research, we added strands, yarns, cheesecloth, etc. as an intermediate layer to the structure of the previous application. By doing so, it has been discovered that the above-mentioned disadvantages can be solved advantageously.

In the structure of the present invention, in addition to the strength provided by the heat-resistant substrate layer, a separate layer intended for electrical properties made of mica and a minimum heat-resistant polymer is provided, and a structural base material reinforcing layer is provided. Therefore, the structural strength can be further improved.

91% by weight on one or both sides of the heat-resistant base layer 1
When laminating the sheet layer 2 made of the above granular mica and pulp-like particles of a heat-resistant polymer of 9% or less by weight, an electric material characterized in that strands, yarns, and cheesecloth are provided as the intermediate layer 3. It is an insulating material.

For example, the intermediate layer 3 in Gogo may be arranged by arranging strands or yarns at arbitrary intervals in at least one of the vertical, horizontal, or diagonal directions, or by using a binder or by arranging the strands or yarns. Instead, you can use cheesecloth that has been made into a grid beforehand.

Although such a structure is possible in the embodiments shown in FIGS. 1 and 2, it is not prohibited to further laminate two or more of these as required.

Further, as a method for doing so, the dried layers can be easily laminated by simply superimposing them and heating and pressurizing them to a temperature range in which the heat-resistant polymer softens.

Ultimately, the heat-resistant base material and heat-resistant polymer used in the present invention may be anything as long as they are insulating, but both have moldability and melt or soften when heated. It has to be something.

Generally, the layer 2 made of granular mica and a heat-resistant polymer is obtained by mixing mica and pulp-like particles made of the above polymer and forming the mixture.

On the other hand, the heat-resistant base material layer 1 is made of the above-mentioned polymer.
Fibers and/or fibers made of pulp-like particles alone or in combination with polymers
Alternatively, those obtained by mixing inorganic fibers and making paper, non-woven fabrics, woven fabrics, mesh-like sheets, synthetic films, etc. made of the above-mentioned polymer fibers can be used.

In this way, the sheet layer 2 made of granular mica and pulp-like particles of a heat-resistant polymer is integrated on one or both sides of the heat-resistant base material layer 1 by heating and pressing. Furthermore, if the heat-resistant base material layer requires varnish impregnation,
Nonwoven fabrics, woven fabrics, and mesh-like sheets are preferred, and it is preferable to increase the fiber component in the mixing ratio of pulp-like particles and fibers.

Examples of materials that can be used as the heat-resistant base material include aromatic polymer pulp particles or fibers thereof, such as aromatic polyamide, aromatic polyamideimide, polyester, and aromatic polyester. These include glass net, ceramic, alumina, rock wool and asbestos.

Examples of the granular mica include muscovite-type potash mica, ferruginous mica, reticulite, biotite-phlogopite type phlogopite, and biotite.

Further, as the pulp-like particles of the heat-resistant polymer provided together with the granular mica, aromatic polymers such as aromatic polyamide,
Examples include aromatic polyamideimide, aromatic polyester, polyester, polyolefin, and polycarbonate, and any of these can be used alone or in combination.

Furthermore, the materials as strands, yarns, and cheesecloth are
Any material that is substantially heat resistant and insulative may be used, but in general, synthetic fibers that may or may not contain glass or aromatic compounds can be used.

Furthermore, as described above, the present invention provides a structure in which strands, yarns, or cheesecloth is provided in the intermediate layer between the heat-resistant base material layer 1 and the mica and heat-resistant polymer layer 2 to satisfy structural strength without impairing electrical properties. Therefore, those skilled in the art can develop various applications for it, including mica paper that does not use varnish, and its industrial utility value is great.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, in which Figure 1 shows a strand or yarn with adhesive on one side, Figure 2 shows an example with cheesecloth adhesive on one side, and Figure 3 shows a strand or yarn with adhesive on both sides. Items with yarn 1. Figure 4 shows a double-sided adhesive cheesecloth, in which 1 is a heat-resistant base material layer, 2 is a heat-resistant base layer,
3 indicates a layer consisting of particulate mica and a heat-resistant polymer, and 3 indicates a strand, yarn or cheesecloth, respectively.

Claims (1)

[Scope of utility model registration request] When laminating a sheet layer 2 consisting of pipe-shaped particles of 91% by weight or more of granular mica and 9% by weight or less of a heat-resistant polymer on one or both sides of the heat-resistant base material 1, the intermediate layer 3 may be a strand or yarn. Alternatively, an electrical insulating material characterized by being provided with cheesecloth and heated and pressurized in a temperature range in which the polymer softens without using an adhesive.