KR100433914B1 - Superdielectric high voltage insulation for dynamoelectric machinery - Google Patents

Abstract

The electrically conductive member 2 is insulated with a thin coating 6 of a dendritic insulating composition which interacts with an oligomer bound to an oligomer containing at least one metal of Cr, Sn, Zn.

Description

Super dielectric high voltage insulator for generator machine {SUPERDIELECTRIC HIGH VOLTAGE INSULATION FOR DYNAMOELECTRIC MACHINERY}

_{KAl 2 AlSi 3 O 10 (OH} ) 2 ( moose nose bytes) or _{KMg 3 AlSi 3 O 10 (OH} ) 2 ( sample logo Fight), and silicates of soldiers mica is its particularly high dielectric strength, low dielectric loss, such high Resistance, good thermal stability and excellent corona resistance have long been used as main elements of high voltage electrical insulators in electrical machines above 7Kv. At present, mica is, for example, US patent specification Nos. As shown in 4,112,183 and 4,254,351 (Smith and Smith et al.), They are used in the form of flakes on glass fiber backings that provide the mechanical integrity required for the machine surrounding the coil. In many cases, the mica tape is wrapped around the coil and then impregnated with the low viscosity liquid insulator resin by vacuum-pressure impregnation (“VPI”). Such a process empties the chamber containing the coil to remove air and moisture trapped in the mica tape, and then introduces an insulating resin under pressure to completely fill the mica tape with resin to remove voids and to remove the resin insulator in the mica matrix. It consists of producing. This resin is then cured by a long heating cycle. Indeed, removal of complete voids is difficult, and the voids can cause electrical and mechanical problems. And of course, mica tapes are thick, bulky, and difficult to apply to coils.

Currently used mica problems occur in two areas:

(1) very finely at the interface between mica and polymer insulator

(2) In the VPI process required to completely fill the mica tape layer with polymer insulators.

The mica surface is a problem area because it is not "wet" very well by the insulator resin. Thus, there is a tendency to form voids on the surface of the mica that are not completely removed during emptying of the coil prior to filling with the insulator resin.

Surface treatment of mica and the addition of humectants to the resin have not completely eliminated this problem to date. Such voids can be of great importance both in the electrical performance of the coil and in the mechanical integrity of the coil. Electrically, the voids can act as locations of partial discharges that can increase electrical losses in the coil and degrade the quality of the surrounding insulation over prolonged exposure.

Mechanically, the voids can be the place where delamination begins, which causes a potential collapse of the coil.

The problems associated with the VPI process are the result of some of the steps originally involved:

(1) bake the coil, (2) empty it, (3) impregnate it, and (4) harden it.

Each step is time consuming and must be performed accurately to produce the final coil that meets electrical and mechanical requirements. The process time and scrap coils represent a significant increased cost of the coil fabrication method.

The requirements for using mica as high voltage insulators have been questioned. ABB, Bjorklund et al., 1994 IEEE International Symposium on Electrical Insulation , June 5-8, 1994 pp. 482-484, "A New Rotating Insulator without Mica for Rotating HV Machines," specifies the use of a chromium oxide protective layer for resin enamel as a replacement for aligned paper containing 50% mica, and then as a readily produced copper rotating insulator. . Nonlinearity of chromium oxide obviously has a great effect on the absorption of free electron charge.

Others have previously experimented with highly positively charged materials with good thermal stability. Drljaca et al. "Insert into montmorillonite with respective chromium (III) hydrolysis oligomers", Vol. 31, No. 23, 1992, pp. 4894-4897 stated that chromium-inserted / intercalated columnar clays have adsorptive and catalytic properties and are a viable alternative to zeolites, sodium or calcium aluminosilicates used for ion exchange water softening. Drljaca et al., “A New Method for Generating Chromium (III) Inserted Clay”, Inorganica Chimica Acta , 256, 1997, pp. 151-154, are described as montmorillonite clays, Al ₂ O ₃ · 4 SiO ₂ · H ₂ O. The reaction of Cr (III) dimers with other dimer units to form a flat sheet for insertion has also been described.

Still involved in clay, but in other areas, Miller is "a small clay particle pack unique property punch" Plastic World , Fillers, October 1997, pp. 36-38 describes inorganic filled plastic nanocomposites with excellent mechanical strength, heat resistance, flame resistance and gas-barrier properties. These composites originally used nylon materials containing bundles of small plates of montmorillonite clay, about 0.5 micrometers to 2 micrometers wide and 1 nanometer (nm) thick, or 0.001 micrometers thick, used as automotive timing belts. . More recently, attempts have been made to bond such small plates to other resins. Miller describes a small plate as having a high "aspect ratio", that is, a high width relative to the thickness, during which molecular bonds are formed between the plate and the polymer. Clay producers such as Nancor Inc. and AMCOL Intl. Have found that the spacing between plates is from about 4 Angstrom units, about 0.0004 micrometers, so that organic resin molecules can be directly ionically or covalently bonded to the surface of a small plate. It chemically stretches, ie "opens" to such a thickness that it can adhere, causing the plates to react directly into the polymer structure during the subsequent polymerization / compound. Plate bundles are also stripped into individual plates by clay producers to assist in polymerization / combination. The molecular “tail”, as Miller mentions, has the chemical function of overcoming incompatibility between hydrophilic clays (with water affinity) and hydrophobic (water repellent) organic polymers and allows them to form molecular bonds directly. . That is, the polymer is inserted directly into the nanoclay. In addition to the timing belt, further use is indicated by thermoplastic gas barrier packing, microwave containers, and epoxy resin circuit boards.

This process is also described in US Pat. 4,889,885, generally described by Usuki et al., Of Yoyota Chou. There, onium ions from materials such as ammonium salts, sulfonium salts and phosphonium salts have been used to extend the interlayer distances of clays such as montmorillonite through ion exchange with inorganic ions in clay minerals. This causes the clay mineral to bring the polymer into the interlayer space and directly connect the polymer and the layer of clay inorganic to each other through ionic bonding. The onium salt has a molecular skeleton that serves as a polymerization initiator. If the onium salt has a molecular skeleton that is the basic structural unit of the resin, the salt will have a phenol group (for phenol resins), an epoxy group (for epoxy resins), and a polybutadiene group (for acrylonitrile butadiene rubber). Yano and Usuki et al. Of Toyota R & D, "Synthesis and Characterization of Polyamide-Clay Hybrids," Journal of Polymer Science , Part A, Polymer Chemistry, Vol. 31, 1993, pp. 2493-2498 describes the use of montmorillonite with an ammonium salt of dodecylamine as an aligned filler in polyamide resin hybrids, used as gas barrier films. There, sodium type montmorillonite was mixed with hot water to disperse sodium, and then replaced with ammonium salts of dodecylamine that interacted with dimethylacetamide ("DMAC") and "opened" a plate of montmorillonite. The intercalated montmorillonite is then simply dispersed into a polyamide matrix and cast into the membrane, where the montmorillonite oriented parallel to the membrane surface provides a barrier to gas penetration.

Peeling of the plate bundles and polymer insertion are also described in US Pat. 5,698,624 to Beall et al. Here the polymerizable monomer is mixed with the material inserted or stripped directly between the plates and then polymerized. Suitable polymers specified are in particular polyamides, polyesters, polyurethanes, polyepoxides. Here the organic ammonium molecules are inserted into sodium or calcium montmorillonite clay plates, increasing the thickness in the plates, "opening", followed by high shear mixing to strip off the silicate layer and then mixing it directly with the matrix polymer to mechanically Improves strength and / or high temperature properties. All cases of plate and polymer interactions appear to be direct interactions between polymers and "open" nanoplates. Other patents in this field are disclosed in US Patent Specification Nos. 5,721,306; 5,760,121; and 5,804,613 (Tsipursky et al .; Beall et al .; and Beall et al., Respectively).

Impregnated and vacuum pressure impregnated mica tapes remain the standard for high voltage electrical insulators and chromium oxide overcoatings demonstrate improved PD (partial discharge) resistance, but with a single application while having all the desirable properties of bulky mica matrix insulators. There is still a need for ultra-thin low cost high voltage electrical insulators that can be dip coated, sprayed or extruded on high voltage electrical conductors.

The present invention relates to an epoxy resin of high dielectric strength capability that provides a high voltage epoxy resin matrix for embedded silicates using epoxy chromium ion bonds in the silicate material embedded with chromium upon curing. These resins can be used extensively for insulators of generators, stators and rotors. High dielectric strength allows its use as a very thin insulator and allows for low cost dip coating or spray processes.

Accordingly, a primary object of the present invention is to provide an improved low cost, high voltage electrical insulator that can replace impregnated mica flakes or mica tapes and still be applied to thin cross sections while still providing high voltage protection and having high voltage durability. To provide.

A further object of the present invention is to provide a low cost, high voltage electrical insulator that still has a dramatic improvement in voltage durability while still using a silicon containing component, and thus can be applied to thin sections.

It is furthermore an object of the present invention to provide a low cost, high voltage that can be applied to thin sections while still utilizing some of the advantages of tin and chromium compounds as demonstrated by the Smith '183 patent and chromium and zinc compounds as claimed by the Smith et al' 351 patent. It is to provide an electrical insulation.

The above and other objects of the present invention are insulated with a coating of a resin which interacts with and binds an oligomer containing a metal selected from the group consisting of Cr, Sn, Zn, and mixtures thereof, the oligomer comprising Al.Si.O. Placed within the structure, the structure is achieved by providing an electrically conductive member consisting of a resin weight of about 3 wt.% To 35 wt.%. Preferably the coating is 0.1 cm to 0.3 cm thick and is dip coated, sprayed or extruded onto a substrate, such as a conductor, where the conductor can be a metal coil for a generator machine, such as an electrical generator of 7 Kv or more.

The invention also relates to a process for producing a resin coating suitable for use as an electrical insulator. The method comprises (a) providing an oligomer containing a metal selected from the group consisting of Cr, Sn, Zn, and mixtures thereof; (b) providing a material of solid Al.Si.O based material having a plate shape and having a space that can be expanded between their component plates; (c) selected from the group consisting of polyepoxide resins, styrenic polyepoxide resins, polyester resins and 1,2-polybutadiene resins, which can interact and polymerize in the presence of Cr, Sr, Zn Providing a liquid resin; (d) inserting the oligomer containing the metal into the space in the solid Al.Si.O base material; And (e) the liquid resin and the solid metal-inserted Al.Si.O-based material are in contact with each other to form a resin mixture such that the metal-inserted Al.Si.O solid is dispersed in the liquid resin. Further steps include (f) applying the resin mixture to the substrate; Then (g) the metal intercalated Al.Si.O liquid resin mixture is heated so that the resin interacts with the metal to interact with the liquid resin and the oligomers and polymerize the resin therewith around the Al.Si.O solid. Causing the reaction to provide an Al.Si.O ₂ solid in the cured polymerized solid matrix of the resin.

Particularly useful resins are solvent-free polyepoxide (epoxy) resins, styrenic polyepoxide resins, polyester resins, and 1,2-polybutadiene resins. They all interact and polymerize in the presence of a catalyst of Cr, Sr, Zn. Preferred Al.Si.O structures are montmorillonite and preferred oligomers are Cr (III) oligomers. The voltage endurance of these materials is greater than 1000 hours at 7.5 Kv / mm (188 volts / mil) and is generally in the much larger range of 2800-3000 hours at 188 volts / mil. For example, the general range of unfilled epoxy resin is 1000 hours @ 188 volts / mil, so the resin of the present invention can be applied at a thickness below 0.063 cm (0.025 inch) at voltages up to 35 Kv.

These and other advantages of the present invention will become apparent from the following description of the drawings. FIG. 1 is a cross-sectional view of an encapsulated electrical article having a thin spray coating of the insulator of the present invention, which best represents the present invention. 2 is a cross-sectional view of a motor containing a coil insulated with a thin dip coated or extruded layer of insulator of the present invention. FIG. 3 is a generator comprising a coil insulated with a dip coated or extruded layer of insulator of the present invention. Fig. 4 is an ideal schematic diagram showing the reaction sequence used in the present invention. Fig. 5 is a comparative graph of the average life of the control sample A and the intercalated material B of the present invention. The chemical structural formula of one resin composition that can be used in the present invention. FIG. 7A is one chemical structural formula corresponding to R shown in FIG. 6. FIG. FIG. 8 is a chemical formula of the bisphenol epoxide used in the present invention. FIG. 9 is a chemical formula of the polymer of the present invention. FIG. 10 is one chemical structure of the oligomer of the present invention. 11 is an additional chemical structure of the oligomers of the present invention. FIG. 12 is a chemical structure of dimer chains formed by the reaction between oligomers of the present invention. FIG. 13 shows a comparison of charge / radius ratios of various cations in accordance with the present invention. Table 14 provides a table providing short term voltage breakdown for various embedded clays in accordance with the present invention. Description of Preferred Embodiments

Referring now to FIG. 1, an insulated electrical member such as coil 2 is shown, which has a lid 4 contained in a thin cured insulated casing 6, the casing having the resin of the invention applied to the member. Composition. 1 is thus illustrative of certain articles of the invention. That is, electrical or electronic components encapsulated or encapsulated in the applied composition of the present invention.

2 shows a cross section of one embodiment of the motor 20. The motor has a slot 22 in it, contains an insulated coil 23, and is surrounded by a metal armature 24 having a slot 25 therein with respect to the stator circumference at 26. 21). The stator slot includes an insulated coil 27. All insulators coated on the coil substrates 23 and 27 can constitute the resin composition of the present invention. 3 shows a cross section of one embodiment of a generator 30. The generator has a slot 32 inside and contains an insulated coil 33 and surrounded by a metal rotor 31, which is surrounded by a metal stator 34 having a slot 35 therein about the stator circumference at 36. The same substrate component. The stator slot contains an insulated coil 37 and also contains internal cooling channels although not shown. All insulators coated on the coils 33 and 37 may comprise the resin composition of the present invention.

One type of resin composition that can be used in the present invention is the reaction of epichlorohydrin and dihydric phenol in alkaline medium at about 50 ° C. using 1-2 or more moles of epichlorohydrin per mole of dihydric phenol. Can be obtained by Heating continues for several hours to react, and the product is then washed to remove salts and bases. The product is generally a complex mixture of glycidylpolyethers instead of one simple compound. However, the main product is represented by the chemical structural formula shown in FIG. 6. In the chemical formula n is a continuous integer 0,1,2,3 ...., and R represents the divalent hydrocarbon radical of the divalent phenol. Typically divalent hydrocarbon radicals have a composition similar to that shown in FIG. 7A, providing diglycidyl ethers of bisphenol A type epoxides. It is noted that the divalent hydrocarbon radicals also have a composition similar to that shown in FIG. 7B, which provides the diglycidyl ether of the bisphenol F type epoxide resin.

Bisphenol epoxides used in the present invention have greater than one 1,2-epoxy equivalent. They will generally be diepoxides. Epoxy equivalent refers to the average number of 1,2-epoxy groups as shown in Figure 8, contained in the average molecule of glycidyl ether.

Other glycidyl ether resins useful in the present invention include polyglycidyl ethers of novolacs, such as phenol formaldehyde condensates, prepared by reaction of epihalohydrin with aldehydes. Alicyclic epoxides are also useful as glycidyl ester epoxy resins, both of which are aglycidyl ether epoxides, both of which are well known in the art and described in detail in US Pat. No. 4,254,351 by Smith et al, Epoxidized polybutadienes which are also useful in the present invention are described. All these resin compositions described previously will now be defined and described as "polyepoxide resin".

Other useful resins include polyester, 1-2 polybutadiene, all of which are well known in the art. Generally, polyester resins are a large group of synthetic resins, almost all of which are made by reaction of dibasic acids with dihydric alcohols. In a few cases, trifunctional monomers such as glycerol or citric acid are used. The term "polyester resin" applies especially to products made from unsaturated dibasic acids such as maleic acid. Unsaturated polyester resins can be further polymerized through crosslinking. Often, other unsaturated monomers, such as styrene, are added during this second stage of the polymerization, which can take place at room temperature with a suitable peroxide catalyst. Maleic anhydride and fumaric acid are common unsaturated acid components, while phthalic anhydride or adipic or azelaic acid are the corresponding saturated substances. Commonly used glycols are ethylene, propylene, diethylene, dipropylene, and some butylene glycols. The polymerizable monomer added is styrene, vinyltoluene, diallyl phthalate or methyl methacrylate. In addition to unsaturated polyester resins, there are other important types. One large group is alkyd resins. They are made from saturated acids and alcohol monomers, with a variety of modifications, usually including unsaturated fatty acids.

Generally 1,2-polybutadiene is a synthetic rubber made from butadiene H ₂ C═CH—CH═CH ₂ . In the 1,2- form, butadiene causes polymerization of 1,2- so that No. 1 carbon of each butadiene molecule is attached to No. 2 carbon of another molecule. When this happens, the main backbone of the resulting polymer contains only No. 1 and No. 2 carbons, while all No. 3 and No. 4 carbons are in the vinyl side chain, for example as shown in FIG. 9. These 1,2-polybutadienes exist in isotactic, syndiotactic and atactic forms but cannot have cis and trans forms.

Furthermore, a brief description of these resins is given in Rose, The Condensed Chemical Dictionary , 6th Ed. pp.909-911 (1961).

Useful oligomers containing metal M, selected from the group consisting of Cr, Sn, Zn, and mixtures thereof, are, for example, dimer structures, as shown in FIG. 10.

Such oligomers are described by Drljaca et.al in Inorganic Chemistry Vol. 31, No. 23, pp 4894-4897 (1992), as described in greater detail when M = Cr, also among other well-known structures, for example trimers, open tetramers, closed tetramer structures. There may be.

The reaction sequence useful for providing the insulated conductive member of the present invention is shown generally in FIG. 4. The oligomers will be prepared to contain Cr, Sn, Zn, or mixtures thereof. This can generally be achieved by reaction of strong acids (ie perchloric acid) with metal salts (chromium nitrate, tin chloride dehydrate, zinc nitrate hydrate).

One particularly useful Cr (III) oligomer is chromium (III) 2,4-pentane diionate having the composition shown in FIG. See also FIG. 4 further. Here, oligomers of this type are indicated by reference numeral 40.

Such oligomers can optimally react with each other to form dimer rings in the form of planar sheets about 0.0004-0.0009 micrometers (4-9 Angstrom units) thick. This is shown in Figure 12, for example Drljaca et al. Inorganica Chimica Acta , 256 (1997) pp. It is specified in 151-154.

A material of solid Al.Si.O based material, such as unmodified mica-type silicate, having a plate form and spaces between component plates that can be expanded is generally represented as 42 in FIG. 4. Clay type silicates such as, for example, unmodified muskobite mica, phlogopite mica or montmorillonite, or mixtures thereof, such materials, generally represented by (43), may be used to increase or even increase the spacing between component plates. It can be processed to be "open" so that oligomers and organic resin molecules can be inserted into mica or clay plates and the results are shown in step (2). As a normal previous step, these mica or clay plates help extend mica or clay interlayer distances or spacing and make their materials less hydrophilic and more hydrophobic, so that hydrophobic polymer materials are generally easier to interact with mica or clay. It may be treated chemically by contact with amines, onium salts such as ammonium salts, or other chemicals added in an amount effective to allow it to function.

In step 2, as mentioned in the background above, the oligomer 40 containing the metal is placed in the open Al.Si.O base material, i.e., inserted therein, so that the structure 43 ', eg For example, muscobite KAl ₂ AlSi ₃ O ₁₀ (OH) ₂ , phlogopite KMg ₃ AlSi ₃ O ₁₀ (OH) ₂ or montmorillonite Al ₂ O ₃ .4SiO ₂ .H ₂ O. This is in one way dissolving the oligomer containing the metal in a suitable solvent, for example ketone chromium (III) 2.4-pentanedionate, and then contacting the solution with the Al.Si.O ₂ base material for an effective time, Followed by drying.

The metal-containing oligomer, now disposed in the "open" Al.Si.O material, is represented entirely by (43 '), which polymerizes with itself and also contains the metal disposed in the Al.Si.O material. To interact with a suitable resin composition capable of polymerizing with oligomers.

Inset mica, clay, etc. 43 'mixed with a suitable resin composition 44 is shown in step (2).

The oligomer-metal containing the range of Al.Si.O ₂ to the resin is about 3 wt% to 35 wt%, preferably 5 wt% to 20 wt%. As shown in step (3) of FIG. 4, upon heating, the resin composition 44 will form a polymer 46 with chain linkages in and around the Al.Si.O material 43.

The mechanism that causes the protection of the polymer material from electrical breakdown can be explained as follows. Mica is the only material that has a high resistance to partial discharge, thereby increasing the voltage durability and life of the insulating material. It is now generally believed that the mechanisms responsible for this protective habit are electronic, not physical. High energy electrons resulting from partial discharges (sometimes referred to as "electron avalanches") are slowed down and lost energy by the strong positive field generated by the arrangement of K ⁺ ions trapped in a silicate lattice cluster. This effect is clearly the cause of the protective properties of mica in the original high voltage insulation system.

As will be evident later in the field of use of the present invention, the concepts and technical approaches sought here have been made on the basis of this electronic deactivation mechanism. The selection of transition metal salts can be guided by considering the charge / size ratio. One mechanism by which mica is effective at capturing free electrons is the presence of K ⁺ ions in the lattice cluster. These ions are usually held very tightly and are very effective scavengers of free electrons.

In general, transition metal ions have a higher charge and a smaller size, and thus a much higher charge / size ratio. Some examples are shown in the table of FIG. 13. The concept provides an insulating material with partial discharge protection (and thus longer voltage durability) that is much more effective than that found in mica by replacing K ⁺ ions with metal ions in this lattice cluster. This is because the higher charge / radius ratio of these metal ions will give more efficient energy removal of the fast charges causing damage to the insulating material.

The resulting composition may be applied to an electrical member such as a wire or coil, an electronic component or the like. The insulating effect of the composition is extraordinary and it will be enough to be applied to a cross section as thin as 0.06 cm. When fully developed, this new dielectric material can be used in high performance molded resins or as an alternative to advanced mica tapes for vacuum pressure impregnated resin production. The ultimate revenue will be an opportunity to dramatically reduce their base wall thickness beyond current levels.

Ultimately, the insulation system, ie 0.005 cm (0.002 inch) thickness, may very well be the result of this development in generator coils. The very high dielectric capability of these materials will enable such extremely thin insulation layers to be used.

Various other high voltage applications benefit from these materials by developing improved insulation for rotors, high dielectric patches for repairing damaged stator coils, and solid insulation for phase leads and series connectors in hot air-cooled generators. Can be.

The invention will now be further illustrated by the following examples.

Example 1

The type of mica-type silicate used in this experiment was Aldrich Chemical Co. Montmorillonite silicate clay (trade name "K-10"). This material has the following characteristics: non-flowing white powder, particle surface area 220-270m ² / g and volume density 300-370 g / l. A solution of 1 g octadecylamine (“ODA”), which is a primary amine in 150 ml ethanol / water (50/50 v / v), also from Aldrich Chemical Co., was heated to 45 ° C. Separately, 1 g of silicate clay was suspended in 100 ml water and added to octadecylamine solution to open a small plate gap. After heating at 70 ° C. for 10 hours, the mixture was filtered and washed with fresh ethanol / water (50/50 v / v). The product was dried in air and then placed in a vacuum oven at 50 ° C. for 10 hours, which finally gave the silicate clay a more open structure suitable for insertion. The silicate was then treated with chromium (III) 2,4-pentanedionate having the formula [C ₅ H ₇ O ₂ ] ₃ Cr available from Aldrich Chemical Co. This reaction was carried out by dissolving the chromium compound in methylethyl ketone and stirring with silicate at room temperature for 2 hours. The resulting product was air-dried and then placed in a 50 ° C. vacuum oven for 12 hours to obtain Cr ( ³⁺ ) embedded clay.

The chromium embedded clay was then suspended in a liquid polyepoxide vacuum pressure impregnation resin made according to the instructions of US Pat. No. 4,254,351, and cast into a 10.2 cm diameter cake sample. These samples were gelled at 135 ° C. for 2 hours and then heated for 16 hours at 150 ° C. until complete curing. Typically, chromium intercalated silicate was added to the epoxy resin at a 10% (by weight) level. Control samples of polyepoxide resin alone were also cast and cured into a 10.2 cm diameter cake sample as above.

The cured Cr ( ³⁺ ) intercalated sample was then subjected to a long term voltage durability test with an epoxy "control sample". Typically, the samples were tested at 24 Kv under oil applying a voltage stress of about 7.5 Kv / mm (188 volts / mil) and the life to failure was observed. The results are shown in FIG. 5, with the average lifespan expressed in hours. This data is the average lifetime of four or more test samples in each group. From the results, epoxy resin sample B containing a chromium-inserted silicate additive has a voltage endurance life more than three times that of “control” sample A, whereby surprisingly the addition of chromium intercalated silicate is advantageous for dielectric strength. Is proved.

Recognizing that this initial experiment was done with normal particle size clay (not nano-sized clay small plates) and that the chromium compound used for intercalation was a standard chromium (III) modification, that is why it was discussed earlier in this specification, namely Because of the more effective intercalation with chromium and better dispersion of dielectric enhancement additives in the resin matrix, it is expected that even more surprising voltage endurance performance will be found with chromium oligomers and nano-sized clay plates. The use of Sn or Zn instead of Cr yields equally good results, and styrenic polyepoxides, polyesters and 1,2-polybutadiene resins can replace polyepoxides (epoxy) used above.

Example 2

In addition to the long term voltage endurance test described in Example 1, there are other important tests used in the evaluation of high voltage electrical insulation. One such test is a short term dielectric strength measurement (ASTM D-149) that involves placing a sample of cured resin (typically about 110 mils thick) between two electrodes under oil. The applied voltage increases uniformly from zero to breakdown, the specified speed is 0.5 to 1.0 Kv per second. Typically for electrical insulators of the above specified thickness, the voltage will exceed 35 Kv before breakdown occurs. The dielectric strength voltage breakdown value is then calculated by dividing the voltage at breakdown by the sample thickness (Volts / mil).

Samples of various embedded clays were prepared, cured, and tested using the ASTM D-149 test procedure as previously described in Example 1. In this series of experiments, small-particle sized nanoclays, inserted into chromium oligomers, were also included. The experimental results found are summarized in the table shown in FIG. 14.

The results show that when the clay material is intercalated into metals such as Cr and Sn and added to the epoxy resin at levels of 1% to 9%, the short term voltage breakdown value is significantly higher. This is especially true for nanoclay samples inserted with chromium oligomers, where the dielectric strength of the epoxy is increased by about 23% compared to the nanoclay samples without insertion. It was also observed that the embedded nanoclay material is easier to mix and disperse in the epoxy resin than other embedded clay samples, thereby providing a more homogeneous distribution throughout the sample during curing.

While specific embodiments of the invention have been described in detail, it will be understood by those skilled in the art that various modifications and alternatives may be developed in light of the overall teachings herein. Accordingly, the specific combinations disclosed are merely illustrative and do not limit the scope of the invention, in which all scope of the appended claims and any and all equivalents thereof are provided.

Claims (21)

Insulated with a coating of resin which interacts with an oligomer bound to an oligomer containing metal selected from the group consisting of Cr, Sn, Zn and mixtures thereof, the oligomer being disposed in an Al.Si.O containing structure Wherein the structure comprises about 3 wt% to 35 wt% of the weight of the resin. The insulated member of claim 1 wherein the member is a metal coil. The insulated member of claim 1 wherein the member is a wire. The insulated member of claim 1 wherein the member is an electronic component. The insulated member of claim 1 wherein the Al.Si.O containing structure is selected from mica-type silicates, clay-type silicates and mixtures thereof. The insulated member of claim 1 wherein the oligomer contains Cr. The insulated member of claim 1 wherein the oligomer contains Sn. The insulated member of claim 1 wherein the oligomer contains Zn. The insulated member of claim 1 wherein the resin is selected from the group consisting of polyepoxide resins, styrenic polyepoxide resins, polyester resins, and 1,2-polybutadiene resins. The insulated member of claim 1 wherein the resin coated insulator has greater voltage durability for about 1000 hours at 7.5 Kv / mm (188 volts / mil). The insulated member of claim 1 wherein the member is a copper coil in an electrical generator. A resin coating composition suitable for use as an electrical insulator comprising a resin that interacts with an oligomer bound to an oligomer containing a metal selected from the group consisting of Cr, Sn, Zn and mixtures thereof, wherein the oligomer is Al.Si. Wherein the structure is comprised between about 3 wt.% And about 35 wt.% Of the weight of the resin. 13. The composition of claim 12, wherein the Al.Si.O containing structure is selected from mica-type silicates, clay-type silicates and mixtures thereof. 13. The composition of claim 12, wherein the oligomer contains Cr. 13. The composition of claim 12 wherein the oligomer contains Sn. 13. The composition of claim 12, wherein the oligomer contains Zn. 13. The composition of claim 12 wherein the resin is selected from the group consisting of polyepoxide resins, styrenic polyepoxide resins, polyester resins and 1,2-polybutadiene resins. As a method of producing a resin coating suitable for use as an electrical insulator, (A) providing an oligomer containing a metal selected from the group consisting of Cr, Sn, Zn and mixtures thereof; (B) providing a solid Al.Si.O based material having a small plate shape and having a space that can be expanded between the small plates that are their components; (C) a liquid selected from the group consisting of polyepoxide resins, styrenic polyepoxide resins, polyester resins and 1,2-polybutadiene resins which can interact and polymerize in the presence of Cr, Sr, Zn Providing a resin; (D) inserting the oligomer containing the metal into the space in the solid Al.Si.O base material; And (E) bringing the liquid resin and the Al.Si.O base material into which the solid metal is inserted into contact with each other and forming a resin mixture, such that the Al.Si.O solid into which the metal is inserted is dispersed in the liquid resin. Manufacturing method. 19. The method of claim 18, comprising the following additional steps. (F) applying the resin mixture to the substrate; And (G) heating the metal-inserted Al.Si.O liquid resin mixture, the resin interacts with the metal, thereby interacting with the liquid resin and oligomers, and polymerizing them around the resin and around the Al.Si.O solids. Producing an Al.Si.O solid in a cured polymerized solid matrix of resin. 19. The Al.Si.O solid plate material is processed by contacting with a material that expands the space between the component platelets in step (B), wherein the Al.Si.O containing structure is mica-type silicate. , Clay-type silicates, and mixtures thereof. 19. The method of claim 18, wherein the cured matrix of resin and the Al.Si.O solid have a voltage endurance greater than about 1000 hours at 7.5 Kv / mm.